Impact of performance considerations on formal specification design

Different client applications of a given functional behaviour usually have different performance requirements. Designing a formal interface specification of the functional behaviour to allow for alternative implementations, and hence, to be suitable for clients with varying performance requirements, is a challenging task. The specifier must consider ramifications of alternative designs on performance to produce a truly implementation-neutral (and hence, performance-neutral) functionality specification. This paper illustrates the influence of performance-both duration and capacity — considerations using a case study in object-based software specification. When these considerations are combined with concerns for comprehensibility and full abstraction, specifications that result that are arguably among the most desirable.