Agile Testing Methods, Techniques, and Tools

Agile Testing Methods

There are certain testing practices that can be followed in every development project (agile or not) to produce quality products. These include writing tests in advance to express proper behaviour, focusing on early defect prevention, detection, and removal, and ensuring that the right test types are run at the right time and as part of the right test level. Agile practitioners aim to introduce these practices early. Testers in Agile projects play a key role in guiding the use of these testing practices throughout the lifecycle. 

Test-Driven Development, Acceptance Test-Driven Development, and Behaviour-Driven Development

Test-driven development, acceptance test-driven development, and behaviour-driven development are three complementary techniques in use among Agile teams to carry out testing across the various test levels. Each technique is an example of a fundamental principle of testing, the benefit of early testing and QA activities, since the tests are defined before the code is written. 

Test-Driven Development

Test-driven development (TDD) is used to develop code guided by automated test cases. The process for test-driven development is:

  • Add a test that captures the programmer’s concept of the desired functioning of a small piece of code
  • Run the test, which should fail since the code doesn’t exist
  • Write the code and run the test in a tight loop until the test passes
  • Refactor the code after the test is passed, re-running the test to ensure it continues to pass against the refactored code
  • Repeat this process for the next small piece of code, running the previous tests as well as the added tests

The tests written are primarily unit level and are code-focused, though tests may also be written at the integration or system levels. Test-driven development gained its popularity through Extreme Programming, but is also used in other Agile methodologies and sometimes in sequential lifecycles. It helps developers focus on clearly defined expected results. The tests are automated and are used in continuous integration.

Acceptance Test-Driven Development

Acceptance test-driven development defines acceptance criteria and tests during the creation of user stories. Acceptance test-driven development is a collaborative approach that allows every stakeholder to understand how the software component has to behave and what the developers, testers, and business representatives need to ensure this behaviour.

Acceptance test-driven development creates reusable tests for regression testing. Specific tools support creation and execution of such tests, often within the continuous integration process. These tools can connect to data and service layers of the application, which allows tests to be executed at the system or acceptance level. Acceptance test-driven development allows quick resolution of defects and validation of feature behaviour. It helps determine if the acceptance criteria are met for the feature.

Behaviour-Driven Development

Behaviour-driven development allows a developer to focus on testing the code based on the expected behaviour of the software. Because the tests are based on the exhibited behaviour from the software, the tests are generally easier for other team members and stakeholders to understand.

Specific behaviour-driven development frameworks can be used to define acceptance criteria based on the given/when/then format:

Given some initial context,

When an event occurs,

Then ensure some outcomes. 

From these requirements, the behaviour-driven development framework generates code that can be used by developers to create test cases. Behaviour-driven development helps the developer collaborate with other stakeholders, including testers, to define accurate unit tests focused on business needs. 

The Test Pyramid

A software system may be tested at different levels. Typical test levels are, from the base of the pyramid to the top, unit, integration, system, and acceptance. The test pyramid emphasises having a large number of tests at the lower levels (bottom of the pyramid) and, as development moves to the upper levels, the number of tests decreases (top of the pyramid). Usually unit and integration level tests are automated and are created using API-based tools. At the system and acceptance levels, the automated tests are created using GUI-based tools. The test pyramid concept is based on the testing principle of early QA and testing (i.e., eliminating defects as early as possible in the lifecycle). 

Testing Quadrants, Test Levels, and Testing Types

Testing quadrants, align the test levels with the appropriate test types in the Agile methodology. The testing quadrants model, and its variants, helps to ensure that all important test types and test levels are included in the development lifecycle. This model also provides a way to differentiate and describe the types of tests to all stakeholders, including developers, testers, and business representatives. 

In the testing quadrants, tests can be business (user) or technology (developer) facing. Some tests support the work done by the Agile team and confirm software behaviour. Other tests can verify the product. Tests can be fully manual, fully automated, a combination of manual and automated, or manual but supported by tools. The four quadrants are as follows: 

  • Quadrant Q1 is unit level, technology facing, and supports the developers. This quadrant contains unit tests. These tests should be automated and included in the continuous integration process.
  • Quadrant Q2 is system level, business facing, and confirms product behaviour. This quadrant contains functional tests, examples, story tests, user experience prototypes, and simulations. These tests check the acceptance criteria and can be manual or automated. They are often created during the user story development and thus improve the quality of the stories. They are useful when creating automated regression test suites.
  • Quadrant Q3 is system or user acceptance level, business facing, and contains tests that critique the product, using realistic scenarios and data. This quadrant contains exploratory testing, scenarios, process flows, usability testing, user acceptance testing, alpha testing, and beta testing. These tests are often manual and are user-oriented.
  • Quadrant Q4 is system or operational acceptance level, technology facing, and contains tests that critique the product. This quadrant contains performance, load, stress, and scalability tests, security tests, maintainability, memory management, compatibility and interoperability, data migration, infrastructure, and recovery testing. These tests are often automated.

During any given iteration, tests from any or all quadrants may be required. The testing quadrants apply to dynamic testing rather than static testing.

The Role of a Tester

Throughout this article, general reference has been made to Agile methods and techniques, and the role of a tester within various Agile lifecycles. This subsection looks specifically at the role of a tester in a project following a Scrum lifecycle. 

Teamwork 

Teamwork is a fundamental principle in Agile development. Agile emphasises the whole-team approach consisting of developers, testers, and business representatives working together. The following are organisational and behavioural best practices in Scrum teams:

  • Cross-functional: Each team member brings a different set of skills to the team. The team works together on test strategy, test planning, test specification, test execution, test evaluation, and test results reporting.
  • Self-organising: The team may consist only of developers, but, as noted before, ideally there would be one or more testers.
  • Co-located: Testers sit together with the developers and the product owner.
  • Collaborative: Testers collaborate with their team members, other teams, the stakeholders, the product owner, and the Scrum Master.
  • Empowered: Technical decisions regarding design and testing are made by the team as a whole (developers, testers, and Scrum Master), in collaboration with the product owner and other teams if needed.
  • Committed: The tester is committed to question and evaluate the product’s behaviour and characteristics with respect to the expectations and needs of the customers and users.
  • Transparent: Development and testing progress is visible on the Agile task board.
  • Credible: The tester must ensure the credibility of the strategy for testing, its implementation, and execution, otherwise the stakeholders will not trust the test results. This is often done by providing information to the stakeholders about the testing process.
  • Open to feedback: Feedback is an important aspect of being successful in any project, especially in Agile projects. Retrospectives allow teams to learn from successes and from failures.
  • Resilient: Testing must be able to respond to change, like all other activities in Agile projects.

These best practices maximise the likelihood of successful testing in Scrum projects.

Sprint Zero 

Sprint zero is the first iteration of the project where many preparation activities take place. The tester collaborates with the team on the following activities during this iteration:

  • Identify the scope of the project (i.e., the product backlog)
  • Create an initial system architecture and high-level prototypes
  • Plan, acquire, and install needed tools (e.g., for test management, defect management, test automation, and continuous integration)
  • Create an initial test strategy for all test levels, addressing (among other topics) test scope, technical risks, test types, and coverage goals
  • Perform an initial quality risk analysis
  • Define test metrics to measure the test process, the progress of testing in the project, and product quality
  • Specify the definition of “done”
  • Create the task board
  • Define when to continue or stop testing before delivering the system to the customer

Sprint zero sets the direction for what testing needs to achieve and how testing needs to achieve it throughout the sprints.

Integration 

In Agile projects, the objective is to deliver customer value on a continuous basis (preferably in every sprint). To enable this, the integration strategy should consider both design and testing. To enable a continuous testing strategy for the delivered functionality and characteristics, it is important to identify all dependencies between underlying functions and features.

Test Planning

Since testing is fully integrated into the Agile team, test planning should start during the release planning session and be updated during each sprint. Test planning for the release and each sprint should address the issues.

Sprint planning results in a set of tasks to put on the task board, where each task should have a length of one or two days of work. In addition, any testing issues should be tracked to keep a steady flow of testing.

Agile Testing Practices

Many practices may be useful for testers in a scrum team, some of which include: 

  • Pairing: Two team members (e.g., a tester and a developer, two testers, or a tester and a product owner) sit together at one workstation to perform a testing or other sprint task.
  • Incremental test design: Test cases and charters are gradually built from user stories and other test bases, starting with simple tests and moving toward more complex ones.
  • Mind mapping: Mind mapping is a useful tool when testing. For example, testers can use mind mapping to identify which test sessions to perform, to show test strategies, and to describe test data.

These practices are in addition to other practices discussed in this article and previous articles on the basics pages.

Assessing Quality Risks and Estimating Test Effort

A typical objective of testing in all projects, Agile or traditional, is to reduce the risk of product quality problems to an acceptable level prior to release. Testers in Agile projects can use the same types of techniques used in traditional projects to identify quality risks (or product risks), assess the associated level of risk, estimate the effort required to reduce those risks sufficiently, and then mitigate those risks through test design, implementation, and execution. However, given the short iterations and rate of change in Agile projects, some adaptations of those techniques are required.

Assessing Quality Risks in Agile Projects

One of the many challenges in testing is the proper selection, allocation, and prioritisation of test conditions. This includes determining the appropriate amount of effort to allocate in order to cover each condition with tests, and sequencing the resulting tests in a way that optimises the effectiveness and efficiency of the testing work to be done. Risk identification, analysis, and risk mitigation strategies can be used by the testers in Agile teams to help determine an acceptable number of test cases to execute, although many interacting constraints and variables may require compromises.

Risk is the possibility of a negative or undesirable outcome or event. The level of risk is found by assessing the likelihood of occurrence of the risk and the impact of the risk. When the primary effect of the potential problem is on product quality, potential problems are referred to as quality risks or product risks. When the primary effect of the potential problem is on project success, potential problems are referred to as project risks or planning risks.

In Agile projects, quality risk analysis takes place at two places.

  • Release planning: business representatives who know the features in the release provide a high-level overview of the risks, and the whole team, including the tester(s), may assist in the risk identification and assessment.
  • Iteration planning: the whole team identifies and assesses the quality risks.

Examples of quality risks for a system include:

  • Incorrect calculations in reports (a functional risk related to accuracy)
  • Slow response to user input (a non-functional risk related to efficiency and response time)
  • Difficulty in understanding screens and fields (a non-functional risk related to usability and understandability)

As mentioned earlier, an iteration starts with iteration planning, which culminates in estimated tasks on a task board. These tasks can be prioritised in part based on the level of quality risk associated with them. Tasks associated with higher risks should start earlier and involve more testing effort. Tasks associated with lower risks should start later and involve less testing effort.

An example of how the quality risk analysis process in an Agile project may be carried out during iteration planning is outlined in the following steps:

  1. Gather the Agile team members together, including the tester(s).
  2. List all the backlog items for the current iteration (e.g., on a task board).
  3. Identify the quality risks associated with each item, considering all relevant quality
    characteristics.
  4. Assess each identified risk, which includes two activities: categorising the risk and determining its level of risk based on the impact and the likelihood of defects.
  5. Determine the extent of testing proportional to the level of risk.
  6. Select the appropriate test technique(s) to mitigate each risk, based on the risk, the level of risk, and the relevant quality characteristic.

The tester then designs, implements, and executes tests to mitigate the risks. This includes the totality of features, behaviours, quality characteristics, and attributes that affect customer, user, and stakeholder satisfaction. 

Throughout the project, the team should remain aware of additional information that may change the set of risks and/or the level of risk associated with known quality risks. Periodic adjustment of the quality risk analysis, which results in adjustments to the tests, should occur. Adjustments include identifying new risks, re-assessing the level of existing risks, and evaluating the effectiveness of risk mitigation activities.

Quality risks can also be mitigated before test execution starts. For example, if problems with the user stories are found during risk identification, the project team can thoroughly review user stories as a mitigating strategy.

Estimating Testing Effort Based on Content and Risk

During release planning, the Agile team estimates the effort required to complete the release. The estimate addresses the testing effort as well. A common estimation technique used in Agile projects is planning poker, a consensus-based technique. The product owner or customer reads a user story to the estimators. Each estimator has a deck of cards with values similar to the Fibonacci sequence (i.e., 0, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, …), or any other progression of choice (e.g., shirt sizes ranging from extra-small to extra-extra-large). The values represent the number of story points, effort days, or other units in which the team estimates. The Fibonacci sequence is recommended because the numbers in the sequence reflect that uncertainty grows proportionally with the size of the story. A high estimate usually means that the story is not well understood or should be broken down into multiple smaller stories. 

The estimators discuss the feature, and ask questions of the product owner as needed. Aspects such as development and testing effort, complexity of the story, and scope of testing play a role in the estimation. Therefore, it is advisable to include the risk level of a backlog item, in addition to the priority specified by the product owner, before the planning poker session is initiated. When the feature has been fully discussed, each estimator privately selects one card to represent his or her estimate. All cards are then revealed at the same time. If all estimators selected the same value, that becomes the estimate. If not, the estimators discuss the differences in estimates after which the poker round is repeated until agreement is reached, either by consensus or by applying rules (e.g., use the median, use the highest score) to limit the number of poker rounds. These discussions ensure a reliable estimate of the effort needed to complete product backlog items requested by the product owner and help improve collective knowledge of what has to be done. 

Techniques in Agile Projects

Many of the test techniques and testing levels that apply to traditional projects can also be applied to Agile projects. However, for Agile projects, there are some specific considerations and variances in test techniques, terminologies, and documentation that should be considered. 

Acceptance Criteria, Adequate Coverage, and Other Information for Testing

Agile projects outline initial requirements as user stories in a prioritised backlog at the start of the project. Initial requirements are short and usually follow a predefined format. Non-functional requirements, such as usability and performance, are also important and can be specified as unique user stories or connected to other functional user stories. Non-functional requirements may follow a predefined format or standard, such as [ISO25000], or an industry specific standard.

The user stories serve as an important test basis. Other possible test bases include:

  • Experience from previous projects
  • Existing functions, features, and quality characteristics of the system
  • Code, architecture, and design
  • User profiles (context, system configurations, and user behaviour)
  • Information on defects from existing and previous projects
  • A categorisation of defects in a defect taxonomy
  • Applicable standards (e.g., [DO-178B] for avionics software)
  • Quality risks

During each iteration, developers create code which implements the functions and features described in the user stories, with the relevant quality characteristics, and this code is verified and validated via acceptance testing. To be testable, acceptance criteria should address the following topics where relevant:

  • Functional behaviour: The externally observable behaviour with user actions as input operating under certain configurations.
  • Quality characteristics: How the system performs the specified behaviour. The characteristics may also be referred to as quality attributes or non-functional requirements. Common quality characteristics are performance, reliability, usability, etc.
  • Scenarios (use cases): A sequence of actions between an external actor (often a user) and the system, in order to accomplish a specific goal or business task.
  • Business rules: Activities that can only be performed in the system under certain conditions defined by outside procedures and constraints (e.g., the procedures used by an insurance company to handle insurance claims).
  • External interfaces: Descriptions of the connections between the system to be developed and the outside world. External interfaces can be divided into different types (user interface, interface to other systems, etc.).
  • Constraints: Any design and implementation constraint that will restrict the options for the developer. Devices with embedded software must often respect physical constraints such as size, weight, and interface connections.
  • Data definitions: The customer may describe the format, data type, allowed values, and default values for a data item in the composition of a complex business data structure (e.g., the ZIP code in a US mail address).

In addition to the user stories and their associated acceptance criteria, other information is relevant for the tester, including:

  • How the system is supposed to work and be used
  • The system interfaces that can be used/accessed to test the system
  • Whether current tool support is sufficient
  • Whether the tester has enough knowledge and skill to perform the necessary tests

Testers will often discover the need for additional information (e.g., code coverage) throughout the iterations and should work collaboratively with the rest of the Agile team members to obtain that information. Relevant information plays a part in determining whether a particular activity can be considered done. This concept of the definition of done is critical in Agile projects and applies in a number of different ways as discussed in the following sub-subsections. 

Test Levels

Each test level has its own definition of done. The following list gives examples that may be relevant for the different test levels.

  • Unit testing
    • 100% decision coverage where possible, with careful reviews of any infeasible paths
    • Static analysis performed on all code
    • No unresolved major defects (ranked based on priority and severity)
    • No known unacceptable technical debt remaining in the design and the code
    • All code, unit tests, and unit test results reviewed
    • All unit tests automated
    • Important characteristics are within agreed limits (e.g., performance)
  • Integration testing
    • All functional requirements tested, including both positive and negative tests, with the number of tests based on size, complexity, and risks
    • All interfaces between units tested
    • All quality risks covered according to the agreed extent of testing
    • No unresolved major defects (prioritised according to risk and importance)
    • All defects found are reported
    • All regression tests automated, where possible, with all automated tests stored in a common repository
  • System testing
    • End-to-end tests of user stories, features, and functions
    • All user personas covered
    • The most important quality characteristics of the system covered (e.g., performance, robustness, reliability)
    • Testing done in a production-like environment(s), including all hardware and software for all supported configurations, to the extent possible
    • All quality risks covered according to the agreed extent of testing
    • All regression tests automated, where possible, with all automated tests stored in a common repository
    • All defects found are reported and possibly fixed
    • No unresolved major defects (prioritised according to risk and importance)

User Story

The definition of done for user stories may be determined by the following criteria: 

  • The user stories selected for the iteration are complete, understood by the team, and have detailed, testable acceptance criteria
  • All the elements of the user story are specified and reviewed, including the user story acceptance tests, have been completed
  • Tasks necessary to implement and test the selected user stories have been identified and estimated by the team

Feature

The definition of done for features, which may span multiple user stories or epics, may include:

  • All constituent user stories, with acceptance criteria, are defined and approved by the customer
  • The design is complete, with no known technical debt
  • The code is complete, with no known technical debt or unfinished refactoring
  • Unit tests have been performed and have achieved the defined level of coverage
  • Integration tests and system tests for the feature have been performed according to the defined coverage criteria
  • No major defects remain to be corrected
  • Feature documentation is complete, which may include release notes, user manuals, and on-line help functions

Iteration 

The definition of done for the iteration may include the following:

  • All features for the iteration are ready and individually tested according to the feature level criteria
  • Any non-critical defects that cannot be fixed within the constraints of the iteration added to the product backlog and prioritised 
  • Integration of all features for the iteration completed and tested 
  • Documentation written, reviewed, and approved 

At this point, the software is potentially releasable because the iteration has been successfully completed, but not all iterations result in a release. 

Release

The definition of done for a release, which may span multiple iterations, may include the following areas:

  • Coverage: All relevant test basis elements for all contents of the release have been covered by testing. The adequacy of the coverage is determined by what is new or changed, its complexity and size, and the associated risks of failure.
  • Quality: The defect intensity (e.g., how many defects are found per day or per transaction), the defect density (e.g., the number of defects found compared to the number of user stories, effort, and/or quality attributes), estimated number of remaining defects are within acceptable limits, the consequences of unresolved and remaining defects (e.g., the severity and priority) are understood and acceptable, the residual level of risk associated with each identified quality risk is understood and acceptable.
  • Time: If the pre-determined delivery date has been reached, the business considerations associated with releasing and not releasing need to be considered.
  • Cost: The estimated lifecycle cost should be used to calculate the return on investment for the delivered system (i.e., the calculated development and maintenance cost should be considerably lower than the expected total sales of the product). The main part of the lifecycle cost often comes from maintenance after the product has been released, due to the number of defects escaping to production. 

Applying Acceptance Test-Driven Development

Acceptance test-driven development is a test-first approach. Test cases are created prior to implementing the user story. The test cases are created by the Agile team, including the developer, the tester, and the business representatives and may be manual or automated. The first step is a specification workshop where the user story is analysed, discussed, and written by developers, testers, and business representatives. Any incompleteness, ambiguities, or errors in the user story are fixed during this process. 

The next step is to create the tests. This can be done by the team together or by the tester individually. In any case, an independent person such as a business representative validates the tests. The tests are examples that describe the specific characteristics of the user story. These examples will help the team implement the user story correctly. Since examples and tests are the same, these terms are often used interchangeably. The work starts with basic examples and open questions. 

Typically, the first tests are the positive tests, confirming the correct behaviour without exception or error conditions, comprising the sequence of activities executed if everything goes as expected. After the positive path tests are done, the team should write negative path tests and cover non-functional attributes as well (e.g., performance, usability). Tests are expressed in a way that every stakeholder is able to understand, containing sentences in natural language involving the necessary preconditions, if any, the inputs, and the related outputs. 

The examples must cover all the characteristics of the user story and should not add to the story. This means that an example should not exist which describes an aspect of the user story not documented in the story itself. In addition, no two examples should describe the same characteristics of the user story. 

Functional and Non-Functional Black Box Test Design

In Agile testing, many tests are created by testers concurrently with the developers’ programming activities. Just as the developers are programming based on the user stories and acceptance criteria, so are the testers creating tests based on user stories and their acceptance criteria. (Some tests, such as exploratory tests and some other experience-based tests, are created later, during test execution) Testers can apply traditional black box test design techniques such as equivalence partitioning, boundary value analysis, decision tables, and state transition testing to create these tests. For example, boundary value analysis could be used to select test values when a customer is limited in the number of items they may select for purchase. 

In many situations, non-functional requirements can be documented as user stories. Black box test design techniques (such as boundary value analysis) can also be used to create tests for non-functional quality characteristics. The user story might contain performance or reliability requirements. For example, a given execution cannot exceed a time limit or a number of operations may fail less than a certain number of times. 

Exploratory Testing and Agile Testing

Exploratory testing is important in Agile projects due to the limited time available for test analysis and the limited details of the user stories. In order to achieve the best results, exploratory testing should be combined with other experience-based techniques as part of a reactive testing strategy, blended with other testing strategies such as analytical risk-based testing, analytical requirements-based testing, model-based testing, and regression-averse testing. Test strategies and test strategy blending is discussed in the basics Level pages. 

In exploratory testing, test design and test execution occur at the same time, guided by a prepared test charter. A test charter provides the test conditions to cover during a time-boxed testing session. During exploratory testing, the results of the most recent tests guide the next test. The same white box and black box techniques can be used to design the tests as when performing pre-designed testing. 

A test charter may include the following information: 

  • Actor: intended user of the system
  • Purpose: the theme of the charter including what particular objective the actor wants to achieve, i.e., the test conditions
  • Setup: what needs to be in place in order to start the test execution
  • Priority: relative importance of this charter, based on the priority of the associated user story or the risk level
  • Reference: specifications (e.g., user story), risks, or other information sources
  • Data: whatever data is needed to carry out the charter
  • Activities: a list of ideas of what the actor may want to do with the system (e.g., “Log on to the system as a super user”) and what would be interesting to test (both positive and negative tests)
  • Oracle notes: how to evaluate the product to determine correct results (e.g., to capture what happens on the screen and compare to what is written in the user’s manual)
  • Variations: alternative actions and evaluations to complement the ideas described under activities

To manage exploratory testing, a method called session-based test management can be used. A session is defined as an uninterrupted period of testing which could last from 60 to 120 minutes. Test sessions include the following:

  • Survey session (to learn how it works)
  • Analysis session (evaluation of the functionality or characteristics)
  • Deep coverage (corner cases, scenarios, interactions)

The quality of the tests depends on the testers’ ability to ask relevant questions about what to test. Examples include the following:

  • What is most important to find out about the system?
  • In what way may the system fail?
  • What happens if…..?
  • What should happen when…..?
  • Are customer needs, requirements, and expectations fulfilled?
  • Is the system possible to install (and remove if necessary) in all supported upgrade paths?

During test execution, the tester uses creativity, intuition, cognition, and skill to find possible problems with the product. The tester also needs to have good knowledge and understanding of the software under test, the business domain, how the software is used, and how to determine when the system fails.

A set of heuristics can be applied when testing. A heuristic can guide the tester in how to perform the testing and to evaluate the results [Hendrickson]. Examples include:

  • Boundaries
  • CRUD (Create, Read, Update, Delete)
  • Configuration variations
  • Interruptions (e.g., log off, shut down, or reboot)

It is important for the tester to document the process as much as possible. Otherwise, it would be difficult to go back and see how a problem in the system was discovered. The following list provides examples of information that may be useful to document:

  • Test coverage: what input data have been used, how much has been covered, and how much remains to be tested
  • Evaluation notes: observations during testing, do the system and feature under test seem to be stable, were any defects found, what is planned as the next step according to the current observations, and any other list of ideas
  • Risk/strategy list: which risks have been covered and which ones remain among the most important ones, will the initial strategy be followed, does it need any changes
  • Issues, questions, and anomalies: any unexpected behaviour, any questions regarding the efficiency of the approach, any concerns about the ideas/test attempts, test environment, test data, misunderstanding of the function, test script or the system under test
  • Actual behaviour: recording of actual behaviour of the system that needs to be saved (e.g., video, screen captures, output data files)

The information logged should be captured and/or summarised into some form of status management tools (e.g., test management tools, task management tools, the task board), in a way that makes it easy for stakeholders to understand the current status for all testing that was performed.

Tools in Agile Projects

Tools described in the basics Level pages are relevant and used by testers on Agile teams. Not all tools are used the same way and some tools have more relevance for Agile projects than they have in traditional projects. For example, although the test management tools, requirements management tools, and incident management tools (defect tracking tools) can be used by Agile teams, some Agile teams opt for an all-inclusive tool (e.g., application lifecycle management or task management) that provides features relevant to Agile development, such as task boards, burn-down charts, and user stories. Configuration management tools are important to testers in Agile teams due to the high number of automated tests at all levels and the need to store and manage the associated automated test artefacts.

In addition to the tools described in the basic Level pages, testers on Agile projects may also utilise the tools described in the following subsections. These tools are used by the whole team to ensure team collaboration and information sharing, which are key to Agile practices.

Task Management and Tracking Tools

In some cases, Agile teams use physical story/task boards (e.g., whiteboard, cork-board) to manage and track user stories, tests, and other tasks throughout each sprint. Other teams will use application lifecycle management and task management software, including electronic task boards. These tools serve the following purposes:

  • Record stories and their relevant development and test tasks, to ensure that nothing gets lost during a sprint
  • Capture team members’ estimates on their tasks and automatically calculate the effort required to implement a story, to support efficient iteration planning sessions
  • Associate development tasks and test tasks with the same story, to provide a complete picture of the team’s effort required to implement the story
  • Aggregate developer and tester updates to the task status as they complete their work, automatically providing a current calculated snapshot of the status of each story, the iteration, and the overall release
  • Provide a visual representation (via metrics, charts, and dashboards) of the current state of each user story, the iteration, and the release, allowing all stakeholders, including people on geographically distributed teams, to quickly check status
  • Integrate with configuration management tools, which can allow automated recording of code check-ins and builds against tasks, and, in some cases, automated status updates for tasks

Communication and Information Sharing Tools

In addition to e-mail, documents, and spoken communication, Agile teams often use three additional types of tools to support communication and information sharing: wikis, instant messaging, and desktop sharing.

Wikis allow teams to build and share an online knowledge base on various aspects of the project, including the following:

  • Product feature diagrams, feature discussions, prototype diagrams, photos of whiteboard discussions, and other information
  • Tools and/or techniques for developing and testing found to be useful by other members of the team
  • Metrics, charts, and dashboards on product status, which is especially useful when the wiki is integrated with other tools such as the build server and task management system, since the tool can update product status automatically
  • Conversations between team members, similar to instant messaging and email, but in a way that is shared with everyone else on the team

Instant messaging, audio teleconferencing, and video chat tools provide the following benefits:

  • Allow real time direct communication between team members, especially distributed teams
  • Involve distributed teams in standup meetings
  • Reduce telephone bills by use of voice-over-IP technology, removing cost constraints that could reduce team member communication in distributed settings

Desktop sharing and capturing tools provide the following benefits:

  • In distributed teams, product demonstrations, code reviews, and even pairing can occur
  • Capturing product demonstrations at the end of each iteration, which can be posted to the team’s wiki

These tools should be used to complement and extend, not replace, face-to-face communication in Agile teams.

Software Build and Distribution Tools

As discussed earlier in this article, daily build and deployment of software is a key practice in Agile teams. This requires the use of continuous integration tools and build distribution tools. The uses, benefits, and risks of these tools was described earlier on the basics of agile page. 

Configuration Management Tools

On Agile teams, configuration management tools may be used not only to store source code and automated tests, but manual tests and other test work products are often stored in the same repository as the product source code. This provides traceability between which versions of the software were tested with which particular versions of the tests, and allows for rapid change without losing historical information. The main types of version control systems include centralised source control systems and distributed version control systems. The team size, structure, location, and requirements to integrate with other tools will determine which version control system is right for a particular Agile project.

Test Design, Implementation, and Execution Tools

Some tools are useful to Agile testers at specific points in the software testing process. While most of these tools are not new or specific to Agile, they provide important capabilities given the rapid change of Agile projects.

  • Test design tools: Use of tools such as mind maps have become more popular to quickly design and define tests for a new feature.
  • Test case management tools: The type of test case management tools used in Agile may be part of the whole team’s application lifecycle management or task management tool.
  • Test data preparation and generation tools: Tools that generate data to populate an application’s database are very beneficial when a lot of data and combinations of data are necessary to test the application. These tools can also help re-define the database structure as the product undergoes changes during an Agile project and refactor the scripts to generate the data. This allows quick updating of test data as changes occur. Some test data preparation tools use production data sources as a raw material and use scripts to remove or anonymise sensitive data. Other test data preparation tools can help with validating large data inputs or outputs.
  • Test data load tools: After data has been generated for testing, it needs to be loaded into the application. Manual data entry is often time consuming and error prone, but data load tools are available to make the process reliable and efficient. In fact, many of the data generator tools include an integrated data load component. In other cases, bulk-loading using the database management systems is also possible.
  • Automated test execution tools: There are test execution tools which are more aligned to Agile testing. Specific tools are available via both commercial and open source avenues to support test first approaches, such as behaviour-driven development, test-driven development, and acceptance test-driven development. These tools allow testers and business staff to express the expected system behaviour in tables or natural language using keywords.
  • Exploratory test tools: Tools that capture and log activities performed on an application during an exploratory test session are beneficial to the tester and developer, as they record the actions taken. This is useful when a defect is found, as the actions taken before the failure occurred have been captured and can be used to report the defect to the developers. Logging steps performed in an exploratory test session may prove to be beneficial if the test is ultimately included in the automated regression test suite.

Cloud Computing and Virtualisation Tools

Virtualisation allows a single physical resource (server) to operate as many separate, smaller resources. When virtual machines or cloud instances are used, teams have a greater number of servers available to them for development and testing. This can help to avoid delays associated with waiting for physical servers. Provisioning a new server or restoring a server is more efficient with snapshot capabilities built into most virtualisation tools. Some test management tools now utilise virtualisation technologies to snapshot servers at the point when a fault is detected, allowing testers to share the snapshot with the developers investigating the fault.

Agile Software Development

Basics of Agile Software Development

A tester on an Agile project will work differently than one working on a traditional project. Testers must understand the values and principles that underpin Agile projects, and how testers are an integral part of a whole-team approach together with developers and business representatives. The members in an Agile project communicate with each other early and frequently, which helps with removing defects early and developing a quality product. 

Agile Software Development and the Agile Manifesto 

In 2001, a group of individuals, representing the most widely used lightweight software development methodologies, agreed on a common set of values and principles which became known as the Manifesto for Agile Software Development or the Agile Manifesto [Agile-manifesto]. The Agile Manifesto contains four statements of values:

  • Individuals and interactions over processes and tools
  • Working software over comprehensive documentation
  • Customer collaboration over contract negotiation
  • Responding to change over following a plan

The Agile Manifesto argues that although the concepts on the right have value, those on the left have greater value.

Individuals and Interactions

Agile development is very people-centred. Teams of people build software, and it is through continuous communication and interaction, rather than a reliance on tools or processes, that teams can work most effectively.

Working Software

From a customer perspective, working software is much more useful and valuable than overly detailed documentation and it provides an opportunity to give the development team rapid feedback. In addition, because working software, albeit with reduced functionality, is available much earlier in the development lifecycle, Agile development can confer significant time-to-market advantage. Agile development is, therefore, especially useful in rapidly changing business environments where the problems and/or solutions are unclear or where the business wishes to innovate in new problem domains.

Customer Collaboration

Customers often find great difficulty in specifying the system that they require. Collaborating directly with the customer improves the likelihood of understanding exactly what the customer requires. While having contracts with customers may be important, working in regular and close collaboration with them is likely to bring more success to the project.

Responding to Change 

Change is inevitable in software projects. The environment in which the business operates, legislation, competitor activity, technology advances, and other factors can have major influences on the project and its objectives. These factors must be accommodated by the development process. As such, having flexibility in work practices to embrace change is more important than simply adhering rigidly to a plan.

Principles 

The core Agile Manifesto values are captured in twelve principles

  • Our highest priority is to satisfy the customer through early and continuous delivery of valuable software.
  • Welcome changing requirements, even late in development. Agile processes harness change for the customer’s competitive advantage.
  • Deliver working software frequently, at intervals of between a few weeks to a few months, with a preference to the shorter timescale.
  • Business people and developers must work together daily throughout the project.
  • Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.
  • The most efficient and effective method of conveying information to and within a development team is face-to-face conversation.
  • Working software is the primary measure of progress.
  • Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.
  • Continuous attention to technical excellence and good design enhances agility.
  • Simplicity—the art of maximising the amount of work not done—is essential.
  • The best architectures, requirements, and designs emerge from self-organising teams.
  • At regular intervals, the team reflects on how to become more effective, then tunes and adjusts its behaviour accordingly.

The different Agile methodologies provide prescriptive practices to put these values and principles into action.

Whole-Team Approach

The whole-team approach means involving everyone with the knowledge and skills necessary to ensure project success. The team includes representatives from the customer and other business stakeholders who determine product features. The team should be relatively small; successful teams have been observed with as few as three people and as many as nine. Ideally, the whole team shares the same workspace, as co-location strongly facilitates communication and interaction. The whole-team approach is supported through the daily stand-up meetings involving all members of the team, where work progress is communicated and any impediments to progress are highlighted. The whole-team approach promotes more effective and efficient team dynamics.

The use of a whole-team approach to product development is one of the main benefits of Agile development. Its benefits include:

  • Enhancing communication and collaboration within the team
  • Enabling the various skill sets within the team to be leveraged to the benefit of the project
  • Making quality everyone’s responsibility

The whole team is responsible for quality in Agile projects. The essence of the whole-team approach lies in the testers, developers, and the business representatives working together in every step of the development process. Testers will work closely with both developers and business representatives to ensure that the desired quality levels are achieved. This includes supporting and collaborating with business representatives to help them create suitable acceptance tests, working with developers to agree on the testing strategy, and deciding on test automation approaches. Testers can thus transfer and extend testing knowledge to other team members and influence the development of the product.

The whole team is involved in any consultations or meetings in which product features are presented, analysed, or estimated. The concept of involving testers, developers, and business representatives in all feature discussions is known as the power of three.

Early and Frequent Feedback

Agile projects have short iterations enabling the project team to receive early and continuous feedback on product quality throughout the development lifecycle. One way to provide rapid feedback is by continuous integration.

When sequential development approaches are used, the customer often does not see the product until the project is nearly completed. At that point, it is often too late for the development team to effectively address any issues the customer may have. By getting frequent customer feedback as the project progresses, Agile teams can incorporate most new changes into the product development process. Early and frequent feedback helps the team focus on the features with the highest business value, or associated risk, and these are delivered to the customer first. It also helps manage the team better since the capability of the team is transparent to everyone. For example, how much work can we do in a sprint or iteration? What could help us go faster? What is preventing us from doing so? 

The benefits of early and frequent feedback include:

  • Avoiding requirements misunderstandings, which may not have been detected until later in the development cycle when they are more expensive to fix.
  • Clarifying customer feature requests, making them available for customer use early. This way, the product better reflects what the customer wants. 
  • Discovering (via continuous integration), isolating, and resolving quality problems early.
  • Providing information to the Agile team regarding its productivity and ability to deliver.
  • Promoting consistent project momentum.

Aspects of Agile Approaches

There are a number of Agile approaches in use by organisations. Common practices across most Agile organisations include collaborative user story creation, retrospectives, continuous integration, and planning for each iteration as well as for overall release. This subsection describes some of the Agile approaches.

Agile Software Development Approaches

There are several Agile approaches, each of which implements the values and principles of the Agile Manifesto in different ways. In this article , three representatives of Agile approaches are considered: Extreme Programming (XP), Scrum, and Kanban.

Extreme Programming

Extreme Programming (XP), is an Agile approach to software development described by certain values, principles, and development practices.

XP embraces five values to guide development: communication, simplicity, feedback, courage, and respect.

XP describes a set of principles as additional guidelines: humanity, economics, mutual benefit, self-similarity, improvement, diversity, reflection, flow, opportunity, redundancy, failure, quality, baby steps, and accepted responsibility.

XP describes thirteen primary practices: sit together, whole team, informative workspace, energised work, pair programming, stories, weekly cycle, quarterly cycle, slack, ten-minute build, continuous integration, test first programming, and incremental design. 

Many of the Agile software development approaches in use today are influenced by XP and its values and principles. For example, Agile teams following Scrum often incorporate XP practices.

Scrum 

Scrum is an Agile management framework which contains the following constituent instruments and practices: 

  • Sprint: Scrum divides a project into iterations (called sprints) of fixed length (usually two to four weeks).
  • Product Increment: Each sprint results in a potentially releasable/shippable product (called an increment).
  • Product Backlog: The product owner manages a prioritised list of planned product items (called the product backlog). The product backlog evolves from sprint to sprint (called backlog refinement).
  • Sprint Backlog: At the start of each sprint, the Scrum team selects a set of highest priority items (called the sprint backlog) from the product backlog. Since the Scrum team, not the product owner, selects the items to be realised within the sprint, the selection is referred to as being on the pull principle rather than the push principle.
  • Definition of Done: To make sure that there is a potentially releasable product at each sprint’s end, the Scrum team discusses and defines appropriate criteria for sprint completion. The discussion deepens the team’s understanding of the backlog items and the product requirements.
  • Time-boxing: Only those tasks, requirements, or features that the team expects to finish within the sprint are part of the sprint backlog. If the development team cannot finish a task within a sprint, the associated product features are removed from the sprint and the task is moved back into the product backlog. Time-boxing applies not only to tasks, but in other situations (e.g., enforcing meeting start and end times).
  • Transparency: The development team reports and updates sprint status on a daily basis at a meeting called the daily scrum. This makes the content and progress of the current sprint, including test results, visible to the team, management, and all interested parties. For example, the development team can show sprint status on a whiteboard.

Scrum defines three roles:

  • Scrum Master: ensures that Scrum practices and rules are implemented and followed, and resolves any violations, resource issues, or other impediments that could prevent the team from following the practices and rules. This person is not the team lead, but a coach.
  • Product Owner: represents the customer, and generates, maintains, and priorities the product backlog. This person is not the team lead.
  • Development Team: develops and test the product. The team is self-organised: There is no team lead, so the team makes the decisions. The team is also cross-functional.

Scrum (as opposed to XP) does not dictate specific software development techniques (e.g., test first programming). In addition, Scrum does not provide guidance on how testing has to be done in a Scrum project.

Kanban

Kanban is a management approach that is sometimes used in Agile projects. The general objective is to visualise and optimise the flow of work within a value-added chain. Kanban utilises three instruments:

  • Kanban Board: The value chain to be managed is visualised by a Kanban board. Each column shows a station, which is a set of related activities, e.g., development or testing. The items to be produced or tasks to be processed are symbolised by tickets moving from left to right across the board through the stations.
  • Work-in-Progress Limit: The amount of parallel active tasks is strictly limited. This is controlled by the maximum number of tickets allowed for a station and/or globally for the board. Whenever a station has free capacity, the worker pulls a ticket from the predecessor station.
  • Lead Time: Kanban is used to optimise the continuous flow of tasks by minimising the (average) lead time for the complete value stream.

Kanban features some similarities to Scrum. In both frameworks, visualising the active tasks (e.g., on a public whiteboard) provides transparency of content and progress of tasks. Tasks not yet scheduled are waiting in a backlog and moved onto the Kanban board as soon as there is new space (production capacity) available.

Iterations or sprints are optional in Kanban. The Kanban process allows releasing its deliverables item by item, rather than as part of a release. Time-boxing as a synchronising mechanism, therefore, is optional, unlike in Scrum, which synchronies all tasks within a sprint.

Collaborative User Story Creation

Poor specifications are often a major reason for project failure. Specification problems can result from the users’ lack of insight into their true needs, absence of a global vision for the system, redundant or contradictory features, and other miscommunications. In Agile development, user stories are written to capture requirements from the perspectives of developers, testers, and business representatives. In sequential development, this shared vision of a feature is accomplished through formal reviews after requirements are written; in Agile development, this shared vision is accomplished through frequent informal reviews while the requirements are being written

The user stories must address both functional and non-functional characteristics. Each story includes acceptance criteria for these characteristics. These criteria should be defined in collaboration between business representatives, developers, and testers. They provide developers and testers with an extended vision of the feature that business representatives will validate. An Agile team considers a task finished when a set of acceptance criteria have been satisfied.

Typically, the tester’s unique perspective will improve the user story by identifying missing details or non-functional requirements. A tester can contribute by asking business representatives open-ended questions about the user story, proposing ways to test the user story, and confirming the acceptance criteria.

The collaborative authorship of the user story can use techniques such as brainstorming and mind mapping. The tester may use the INVEST technique [INVEST]:

  • Independent
  • Negotiable
  • Valuable
  • Estimable
  • Small
  • Testable

According to the 3C concept, a user story is the conjunction of three elements:

  • Card: The card is the physical media describing a user story. It identifies the requirement, its criticality, expected development and test duration, and the acceptance criteria for that story.
    The description has to be accurate, as it will be used in the product backlog.
  • Conversation: The conversation explains how the software will be used. The conversation can be documented or verbal. Testers, having a different point of view than developers and business representatives, bring valuable input to the exchange of thoughts, opinions, and experiences. Conversation begins during the release-planning phase and continues when the story is scheduled.
  • Confirmation: The acceptance criteria, discussed in the conversation, are used to confirm that the story is done. These acceptance criteria may span multiple user stories. Both positive and negative tests should be used to cover the criteria. During confirmation, various participants play the role of a tester. These can include developers as well as specialists focused on performance, security, interoperability, and other quality characteristics. To confirm a story as done, the defined acceptance criteria should be tested and shown to be satisfied.

Agile teams vary in terms of how they document user stories. Regardless of the approach taken to document user stories, documentation should be concise, sufficient, and necessary.

Retrospectives

In Agile development, a retrospective is a meeting held at the end of each iteration to discuss what was successful, what could be improved, and how to incorporate the improvements and retain the successes in future iterations. Retrospectives cover topics such as the process, people, organisations, relationships, and tools. Regularly conducted retrospective meetings, when appropriate follow up activities occur, are critical to self-organisation and continual improvement of development and testing.

Retrospectives can result in test-related improvement decisions focused on test effectiveness, test productivity, test case quality, and team satisfaction. They may also address the testability of the applications, user stories, features, or system interfaces. Root cause analysis of defects can drive testing and development improvements. In general, teams should implement only a few improvements per iteration. This allows for continuous improvement at a sustained pace.

The timing and organisation of the retrospective depends on the particular Agile method followed. Business representatives and the team attend each retrospective as participants while the facilitator organises and runs the meeting. In some cases, the teams may invite other participants to the meeting.

Testers should play an important role in the retrospectives. Testers are part of the team and bring their unique perspective. Testing occurs in each sprint and vitally contributes to success. All team members, testers and non-testers, can provide input on both testing and non-testing activities.

Retrospectives must occur within a professional environment characterised by mutual trust. The attributes of a successful retrospective are the same as those for any other review as is discussed in previous articles.

Continuous Integration

Delivery of a product increment requires reliable, working, integrated software at the end of every sprint. Continuous integration addresses this challenge by merging all changes made to the software and integrating all changed components regularly, at least once a day. Configuration management, compilation, software build, deployment, and testing are wrapped into a single, automated, repeatable process. Since developers integrate their work constantly, build constantly, and test constantly, defects in code are detected more quickly.

Following the developers’ coding, debugging, and check-in of code into a shared source code repository, a continuous integration process consists of the following automated activities:

  • Static code analysis: executing static code analysis and reporting results
  • Compile: compiling and linking the code, generating the executable files
  • Unit test: executing the unit tests, checking code coverage and reporting test results
  • Deploy: installing the build into a test environment
  • Integration test: executing the integration tests and reporting results
  • Report (dashboard): posting the status of all these activities to a publicly visible location or e-mailing status to the team

An automated build and test process takes place on a daily basis and detects integration errors early and quickly. Continuous integration allows Agile testers to run automated tests regularly, in some cases as part of the continuous integration process itself, and send quick feedback to the team on the quality of the code. These test results are visible to all team members, especially when automated reports are integrated into the process. Automated regression testing can be continuous throughout the iteration. Good automated regression tests cover as much functionality as possible, including user stories delivered in the previous iterations. Good coverage in the automated regression tests helps support building (and testing) large integrated systems. When the regression testing is automated, the Agile testers are freed to concentrate their manual testing on new features, implemented changes, and confirmation testing of defect fixes.

In addition to automated tests, organisations using continuous integration typically use build tools to implement continuous quality control. In addition to running unit and integration tests, such tools can run additional static and dynamic tests, measure and profile performance, extract and format documentation from the source code, and facilitate manual quality assurance processes. This continuous application of quality control aims to improve the quality of the product as well as reduce the time taken to deliver it by replacing the traditional practice of applying quality control after completing all development.

Build tools can be linked to automatic deployment tools, which can fetch the appropriate build from the continuous integration or build server and deploy it into one or more development, test, staging, or even production environments. This reduces the errors and delays associated with relying on specialised staff or programmers to install releases in these environments.

Continuous integration can provide the following benefits:

  • Allows earlier detection and easier root cause analysis of integration problems and conflicting changes
  • Gives the development team regular feedback on whether the code is working
  • Keeps the version of the software being tested within a day of the version being developed
  • Reduces regression risk associated with developer code refactoring due to rapid re-testing of the code base after each small set of changes
  • Provides confidence that each day’s development work is based on a solid foundation
  • Makes progress toward the completion of the product increment visible, encouraging developers and testers
  • Eliminates the schedule risks associated with big-bang integration
  • Provides constant availability of executable software throughout the sprint for testing, demonstration, or education purposes
  • Reduces repetitive manual testing activities
  • Provides quick feedback on decisions made to improve quality and tests

However, continuous integration is not without its risks and challenges:

  • Continuous integration tools have to be introduced and maintained
  • The continuous integration process must be defined and established
  • Test automation requires additional resources and can be complex to establish
  • Thorough test coverage is essential to achieve automated testing advantages
  • Teams sometimes over-rely on unit tests and perform too little system and acceptance testing

Continuous integration requires the use of tools, including tools for testing, tools for automating the build process, and tools for version control.

Release and Iteration Planning 

As mentioned in this article, planning is an on-going activity, and this is the case in Agile lifecycles as well. For Agile lifecycles, two kinds of planning occur, release planning and iteration planning. 

Release planning looks ahead to the release of a product, often a few months ahead of the start of a project. Release planning defines and re-defines the product backlog, and may involve refining larger user stories into a collection of smaller stories. Release planning provides the basis for a test approach and test plan spanning all iterations. Release plans are high-level. 

In release planning, business representatives establish and prioritise the user stories for the release, in collaboration with the team. Based on these user stories, project and quality risks are identified and a high-level effort estimation is performed.

Testers are involved in release planning and especially add value in the following activities:

  • Defining testable user stories, including acceptance criteria
  • Participating in project and quality risk analyses
  • Estimating testing effort associated with the user stories
  • Defining the necessary test levels
  • Planning the testing for the release

After release planning is done, iteration planning for the first iteration starts. Iteration planning looks ahead to the end of a single iteration and is concerned with the iteration backlog.

In iteration planning, the team selects user stories from the prioritised release backlog, elaborates the user stories, performs a risk analysis for the user stories, and estimates the work needed for each user story. If a user story is too vague and attempts to clarify it have failed, the team can refuse to accept it and use the next user story based on priority. The business representatives must answer the team’s questions about each story so the team can understand what they should implement and how to test each story.

The number of stories selected is based on established team velocity and the estimated size of the selected user stories. After the contents of the iteration are finalised, the user stories are broken into tasks, which will be carried out by the appropriate team members.

Testers are involved in iteration planning and especially add value in the following activities:

  • Participating in the detailed risk analysis of user stories
  • Determining the testability of the user stories
  • Creating acceptance tests for the user stories
  • Breaking down user stories into tasks (particularly testing tasks)
  • Estimating testing effort for all testing tasks
  • Identifying functional and non-functional aspects of the system to be tested
  • Supporting and participating in test automation at multiple levels of testing

Release plans may change as the project proceeds, including changes to individual user stories in the product backlog. These changes may be triggered by internal or external factors. Internal factors include delivery capabilities, velocity, and technical issues. External factors include the discovery of new markets and opportunities, new competitors, or business threats that may change release objectives and/or target dates. In addition, iteration plans may change during an iteration. For example, a particular user story that was considered relatively simple during estimation might prove more complex than expected.

These changes can be challenging for testers. Testers must understand the big picture of the release for test planning purposes, and they must have an adequate test basis and test oracle in each iteration for test development purposes as discussed in earlier articles. The required information must be available to the tester early, and yet change must be embraced according to Agile principles. This dilemma requires careful decisions about test strategies and test documentation.

Release and iteration planning should address test planning as well as planning for development activities. Particular test-related issues to address include:

  • The scope of testing, the extent of testing for those areas in scope, the test goals, and the reasons for these decisions.
  • The team members who will carry out the test activities.
  • The test environment and test data needed, when they are needed, and whether any additions or changes to the test environment and/or data will occur prior to or during the project.
  • The timing, sequencing, dependencies, and prerequisites for the functional and non-functional test activities (e.g., how frequently to run regression tests, which features depend on other features or test data, etc.), including how the test activities relate to and depend on development activities.
  • The project and quality risks to be addressed.

In addition, the larger team estimation effort should include consideration of the time and effort needed to complete the required testing activities.

Agile software development

The fundamentals of agile software development

A tester on an Agile project will work differently than one working on a traditional project. Testers must understand the values and principles that underpin Agile projects, and how testers are an integral part of a whole-team approach together with developers and business representatives. The members in an Agile project communicate with each other early and frequently, which helps with removing defects early and developing a quality product.

Agile software development and the agile manifesto

In 2001, a group of individuals, representing the most widely used lightweight software development methodologies, agreed on a common set of values and principles which became known as the Manifesto for Agile Software Development or the Agile Manifesto [Agilemanifesto]. The Agile Manifesto contains four statements of values:

  • Individuals and interactions over processes and tools
  • Working software over comprehensive documentation
  • Customer collaboration over contract negotiation
  • Responding to change over following a plan

The Agile Manifesto argues that although the concepts on the right have value, those on the left have greater value.

Individuals and interactions

Agile development is very people-centered. Teams of people build software, and it is through continuous communication and interaction, rather than a reliance on tools or processes, that teams can work most effectively.

Working software

From a customer perspective, working software is much more useful and valuable than overly detailed documentation and it provides an opportunity to give the development team rapid feedback. In addition, because working software, albeit with reduced functionality, is available much earlier in the development lifecycle, Agile development can confer significant time-to-market advantage. Agile development is, therefore, especially useful in rapidly changing business environments where the problems and/or solutions are unclear or where the business wishes to innovate in new problem domains.

Customer collaboration

Customers often find great difficulty in specifying the system that they require. Collaborating directly with the customer improves the likelihood of understanding exactly what the customer requires. While having contracts with customers may be important, working in regular and close collaboration with them is likely to bring more success to the project.

Responding to change

Change is inevitable in software projects. The environment in which the business operates, legislation, competitor activity, technology advances, and other factors can have major influences on the project and its objectives. These factors must be accommodated by the development process. As such, having flexibility in work practices to embrace change is more important than simply adhering rigidly to a plan.

Agile principles

The core Agile Manifesto values are captured in twelve principles:

  • Our highest priority is to satisfy the customer through early and continuous delivery of valuable software.
  • Welcome changing requirements, even late in development. Agile processes harness change for the customer’s competitive advantage.
  • Deliver working software frequently, at intervals of between a few weeks to a few months, with a preference to the shorter timescale.
  • Business people and developers must work together daily throughout the project.
  • Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.
  • The most efficient and effective method of conveying information to and within a development team is face-to-face conversation.
  • Working software is the primary measure of progress.
  • Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.
  • Continuous attention to technical excellence and good design enhances agility.
  • Simplicity—the art of maximizing the amount of work not done—is essential.
  • The best architectures, requirements, and designs emerge from self-organizing teams.
  • At regular intervals, the team reflects on how to become more effective, then tunes andadjusts its behavior accordingly.

The different Agile methodologies provide prescriptive practices to put these values and principles into action.