SOFTWARE REQUIREMENT SPECIFICATION Chapter 10 SOFTWARE REQUIREMENT SPECIFICATION

Software requirement specification (srs) Is a complete description of the behaviour of the system to be developed. Includes a set of use cases that describes the interaction that the user will have with the software. Use cases = functional requirement. SRS also has non functional requirements (supplementary) included which impose constraints on the design. Ie, quality standards

Benefits of srs Establish the basis for agreement between the customers & the suppliers on what the software product is to do. Reduce the development effort Provide a basis for estimating costs & schedules Provide a baseline for validation & verification Facilitate transfer Serve as a basis for enhancement

Characteristics of a good srs SRS should be; Correct Unambiguous Complete Consistent Ranked for importance & stability Verifiable Modifiable Traceable

Characteristics of a good srs Correct – keep the specification up to date when you find things that are not correct. Unambiguous – every requirement stated has only one interpretation, so fix as soon as you find it. Complete – complete software is the final result Consistent – consistent when you use a word referring to one meaning, don’t keep changing Ranked for importance – some may have marketing value to it. Verifiable – provide a quantitative requirement that gives clear ideas.

Characteristics of a good srs Modifiable – should be able to be modified where ever necessary Traceable – should be traceable.