The “V” Concept of Testing

Life cycle testing involves continuous testing of the system during the developmental process.
At predetermined points, the results of the development process are inspected to determine
the correctness of the implementation. These inspections identify defects at the earliest
possible point.
Life cycle testing cannot occur until a formalized SDLC has been incorporated. Life cycle
testing is dependent upon the completion of predetermined deliverables at specified points
in the developmental life cycle. If information services personnel have the discretion to
determine the order in which deliverables are developed, the life cycle test process
becomes ineffective. This is due to variability in the process, which normally increases cost.
The life cycle testing concept can best be accomplished by the formation of a test team. The
team is comprised of members of the project who may be both implementing and testing
the system. When members of the team are testing the system, they must use a formal testing
methodology to clearly distinguish the implementation mode from the test mode. They also
must follow a structured methodology when approaching testing the same as when
approaching system development. Without a specific structured test methodology, the test
team concept is ineffective because team members would follow the same methodology for
testing as they used for developing the system. Experience shows people are blind to their
own mistakes, so the effectiveness of the test team is dependent upon developing the system
under one methodology and testing it under another.
The life cycle testing concept is illustrated below. This illustration shows that when the project
starts both the system development process and system test process begins. The team that is
developing the system begins the systems development process and the team that is
conducting the system test begins planning the system test process. Both teams start at the
same point using the same information. The systems development team has the responsibility
to define and document the requirements for developmental purposes. The test team will
likewise use those same requirements, but for the purpose of testing the system. At
appropriate points during the developmental process, the test team will test the
developmental process in an attempt to uncover defects. The test team should use the
structured testing techniques outlined in this book as a basis of evaluating the system
development process deliverables.