The management of uncertainty in software development

There are at least two different kinds of uncertainty in software development. Both are centered around software specification. The first type has to do with the uncertainty as to whether or not a given description is truly a specification of the software to be developed. The second type of uncertainty has to do with the lifetime of a valid specification. Most programs have parts that are a mixture of the two types. A high-level view of both types of uncertainty in specification is presented to explain the problems inherent in software development and maintenance. The view supports the need for prototyping throughout software development and maintenance