Verifying Requirements

The most important thing on specifying Requirements is Quality Measure of each Requirement. Quality Measure is specified for a requirement, any solution that meets this measure will be acceptable, and any solution that does not meet the measure will be not acceptable. Quality Measure are used to test the new system against the requirements. Attempting to define the quality Measure for a requirement helps to rationalize fuzzy requirements. For example: everyone would agree with a statement like “System must provide good value”. But each person may have a different interpretation of “Good Value”. In devising the scale that must be used to measure “Good Value”, it will become necessary to identify what that term means. Sometimes requiring the stakeholders to think about a requirement in this way will lead to defining an agreed-upon quality measure. In other cases, there may be no agreement on a quality measure. One solution would be to replace one vague requirement with several unambiguous requirements, each with its own quality measure. It is important that guidelines for requirement development and documentation be defined at the outset of the project. In all but smallest programs, careful analysis is required to ensure that the system is developed properly. Uses Cases are one way to document functional requirements, and can lead to more through system designs and test procedures. In addition to Functional Requirements, it is also important to consider Nonfunctional Requirements, such as performance and security, early in the process. They can determine the technology choices and areas of risk. Nonfunctional Requirements do not endow the system with any specific functions, but rather constrain or further define how the system will perform any given function. Functional Requirements should be specified along with their associated Nonfunctional Requirements.