Software Engineering Institute

A number of methods have been proposed in the last decade for the specification of system and software requirements for time-critical systems. The emerging CASE technology is based heavily on a subset of these methods; yet little objective attention has been paid to the methods themselves. This report describes our objective evaluation of four methods (identified as ESML, Harel, Hatley-Pirbhai, and Ward-Mellor), from identification through detailed assessment. We have avoided the use of small sample problems as the sole basis of our evaluation. We depart from this approach by involving software developers from various application domains, including extended interviews of those who have applied the methods to large-scale projects. The resulting recommendations and conclusions focus on method selection criteria, and on the large-grained impact of using these methods on a given project. 

The primary audience of this report is the software development practitioner involved in the method selection or adoption process. The paper attempts to provide proper context to assist the practitioner in making appropriate method adoption decisions. Secondarily, the results of the paper also should be of to tool vendors, method developers, and program managers.