Testing as a process

Testing as a process

The software development process has been described as a series of phases, procedures, and steps that result in the production of a software product. Embedded within the software development process are several other processes including testing. Some of these are shown in Figure 1.3. Testing itself is related to two other processes called verification and validation as shown in Figure 1.3.

Validation is the process of evaluating a software system or component during, or at the end of, the development cycle in order to determine whether it satisfies specified requirements. Validation is usually associated with traditional execution-based testing, that is, exercising the code with test cases.

Verification is the process of evaluating a software system or component to determine whether the products of a given development phase satisfy the conditions imposed at the start of that phase.

Verification is usually associated with activities such as inspections and reviews of software deliverables. Testing itself has been defined in several ways. Two definitions are shown below.

Testing is generally described as a group of procedures carried out to evaluate some aspect of a piece of software

Testing can be described as a process used for revealing defects in software, and for establishing that the software has attained a specified degree of quality with respect to selected attributes.

Note that these definitions of testing are general in nature. They cover both validation and verification activities, and include in the testing domain all of the following: technical reviews, test planning, test tracking, test case design, unit test, integration test, system test, acceptance test, and usability test. The definitions also describe testing as a dual-purpose process—one that reveals defects, as well as one that is used to evaluate quality attributes of the software such as reliability,

security, usability, and correctness.

Also note that testing and debugging, or fault localization, are two very different activities. The debugging process begins after testing has been carried out and the tester has noted that the software is not behaving as specified.

Testing as a process has economic, technical and managerial aspects. Economic aspects are related to the reality that resources and time are available to the testing group on a limited basis. In fact, complete testing is in many cases not practical because of these economic constraints. An organization must structure its testing process so that it can deliver software on time and within budget, and also satisfy the client‘s requirements. The technical aspects of testing relate to the techniques, methods, measurements, and tools used to insure that the software under test is as defect-free and reliable as possible for the conditions and constraints under which it must operate. Testing is a process, and as a process it must managed. Minimally that means that an organizational policy for testing must be defined and documented. Testing procedures and steps must be defined and documented. Testing must be planned, testers should be trained, the process should have associated quantifiable goals that can be measured and monitored. Testing as a process should be able to evolve to a level where there are mechanisms in place for making continuous improvements.