On many software development projects, software system testing takes considerably longer than predicted. Even worse, the resultant product often fails to meet customer expectations. It is well understood and documented that the requirements specification process as currently practised is grossly inadequate. Perhaps this inadequate requirements process is a cause of the apparent inadequate software system testing process. The paper explores the qualities of a well written requirements specification. It also provides insight into how the lack of each of these qualities can have profound effects on the potential success or failure of software system testing. More attention to quality during the requirements specification process can help alleviate these problems.
software development, software testing, requirements specifications, quality
According to Boehm ~, between 35% and 45% of total software development resources are expended during testing activities on large systems. Finding ways to reduce the testing effort will clearly have a significant effect on total development cost. How can testing be more effective? Many organizations attempt to do this by using better methods during the testing phase. Although this may have an effect, the biggest payoff will come from employing better techniques at the earlier phases of the development life-cycle, specifically during the requirements phase. During the requirements phase, the software requirements specification (SRS) is written; this document is the primary driver in the development of test plans and procedures. This paper explores the qualities of an SRS, with specific emphasis on how any deficits in any of these qualities affects software system testing. Although this paper specifically addresses software requirements and software testing, most of the ideas presented apply equally well to system requirements and system testing. This paper defines and analyses I 1 qualities of an SRS. As deficits are common in most SRSs, a sample of techniques that may be used to reduce their prevalence is discussed. Then the paper is summarized.
An intimate relationship exists between the requirements specification and software system testing phases.