标题: 50 Specific Ways to Improve Your Testing - 04 [打印本页] 作者: angelcc216 时间: 2006-1-10 10:34 标题: 50 Specific Ways to Improve Your Testing - 04 Item 4: Ensure That Requirement Changes Are Communicated
When test procedures are based on requirements, it is important to keep test team members informed of changes to the requirements as they occur. This may seem obvious, but it is surprising how often test procedures are executed that differ from an application's implementation that has been changed due to updated requirements. Many times, testers responsible for developing and executing the test procedures are not notified of requirements changes, which can result in false reports of defects, and loss of required research and valuable time.
There can be several reasons for this kind of process breakdown, such as:
Undocumented changes. Someone, for example the product or project manager, the customer, or a requirements analyst, has instructed the developer to implement a feature change, without agreement from other stakeholders, and the developer has implemented the change without communicating or documenting it. A process needs to be in place that makes it clear to the developer how and when requirements can be changed. This is commonly handled through a Change Control Board, an Engineering Review Board, or some similar mechanism, discussed below.
Outdated requirement documentation. An oversight on the testers' part or poor configuration management may cause a tester to work with an outdated version of the requirement documentation when developing the test plan or procedures. Updates to requirements need to be documented, placed under configuration management control (baselined), and communicated to all stakeholders involved.
Software defects. The developer may have implemented a requirement incorrectly, although the requirement documentation and the test documentation are correct.
In the last case, a defect report should be written. However, if a requirement change process is not being followed, it can be difficult to tell which of the aforementioned scenarios is actually occurring. Is the problem in the software, the requirement, the test procedure, or all of the above? To avoid guesswork, all requirement changes must be openly evaluated, agreed upon, and communicated to all stakeholders. This can be accomplished by having a requirement-change process in place that facilitates the communication of any requirement changes to all stakeholders.
If a requirement needs to be corrected, the change process must take into account the ripple effect upon design, code, and all associated documentation, including test documentation. To effectively manage this process, any changes should be baselined and versioned in a configuration-management system.
The change process outlines when, how, by whom, and where change requests are initiated. The process might specify that a change request can be initiated during any phase of the life cycle梔uring any type of review, walk-through, or inspection during the requirements, design, code, defect tracking, or testing activities, or any other phase.
Each change request could be documented via a change-request form梐 template listing all information necessary to facilitate the change-request process梬hich is passed on to the Change Control Board (CCB). Instituting a CCB helps ensure that any changes to requirements and other change requests follow a specific process. A CCB verifies that change requests are documented appropriately, evaluated, and agreed upon; that any affected documents (requirements, design documents, etc.) are updated; and that all stakeholders are informed of the change.
The CCB usually consists of representatives from the various management teams, e.g., product management, requirements management, and QA teams, as well as the testing manager and the configuration manager. CCB meetings can be conducted on an as-needed basis. All stakeholders need to evaluate change proposals by analyzing the priority, risks, and tradeoffs associated with the suggested change.
Associated and critical impact analysis of the proposed change must also be performed. For example, a requirements change may affect the entire suite of testing documentation, requiring major additions to the test environment and extending the testing by numerous weeks. Or an implementation may need to be changed in a way that affects the entire automated testing suite. Such impacts must be identified, communicated, and addressed before the change is approved.
The CCB determines whether a change request's validity, effects, necessity, and priority (for example, whether it should be implemented immediately, or whether it can be documented in the project's central repository as an enhancement). The CCB must ensure that the suggested changes, associated risk evaluation, and decision-making processes are documented and communicated.
It is imperative that all parties be made aware of any change suggestions, allowing them to contribute to risk analysis and mitigation of change. An effective way to ensure this is to use a requirements-management tool,[11] which can be used to track the requirements changes as well as maintain the traceability of the requirements to the test procedures (see the testability checklist in Item 2 for a discussion of traceability). If the requirement changes, the change should be reflected and updated in the requirements-management tool, and the tool should mark the affected test artifact (and other affected elements, such as design, code, etc.), so the respective parties can update their products accordingly. All stakeholders can then get the latest information via the tool.
[11] There are numerous excellent requirement management tools on the market, such as Rational's RequisitePro, QSS's DOORS, and Integrated Chipware's RTM: Requirement & Traceability Management.
Change information managed with a requirements-management tool allows testers to reevaluate the testability of the changed requirement as well as the impact of changes to test artifacts (test plan, design, etc.) or the testing schedule. The affected test procedures must be revisited and updated to reflect the requirements and implementation changes. Previously identified defects must be reevaluated to determine whether the requirement change has made them obsolete. If scripts, test harnesses, or other testing mechanisms have already been created, they may need to be updated as well.
A well-defined process that facilitates communication of changed requirements, allowing for an effective test program, is critical to the efficiency of the project.