Overview

The complexity and size of software systems are continuously increasing. As the scale changes to more complex and larger software systems, new problems occur that did not exist in smaller systems (or were of minor significance), which leads to a redefining of priorities of the activities that go into developing software. Software requirements is one such area, to which little importance was attached in the early days of software development, as the emphasis was on coding and design. The tacit assumption was that the developers understood the problem clearly when it was explained to them, generally informally.

As systems grew more complex, it became evident that the goals of the entire system could not be easily comprehended. Hence the need for more rigorous requirements analysis arose. Now, for large software systems, requirements analysis is perhaps the most difficult and intractable activity; it is also very error-prone. Many believe that the software engineering discipline is weakest in this critical area.

Some of the difficulty is due to the scope of this activity. The software project is initiated by the client s needs. In the beginning, these needs are in the minds of various people in the client organization. The requirements analyst has to identify the requirements by talking to these people and understanding their needs. In situations where the software is to automate a currently manual process, many of the needs can be understood by observing the current practice. But no such methods exist for systems for which manual processes do...