Object oriented requirements capture and analysis — The ORCA project

Abstract

The Object Oriented Requirements Capture and Analysis method has been developed by the ORCA Project (Data Dictionary Systems Limited, Logica Cambridge Limited and the University of York). We believe that any well founded method must have a clear definition of the information to be collected during the use of the method. This paper describes the model of the information base (metamodel) for the ORCA method. It describes the concepts used by the method and the structures required to support their use.

ORCA provides techniques for the analysis of the purpose of a system and for arguing about whether subsystems meet the demands they place on each other. ORCA provides techniques for the modelling of intrinsic behaviour which are similar to other class modelling approaches. However, ORCA also provides techniques for modelling extrinsic behaviour, which we believe is a novel component of the ORCA method and a powerful aid to reuse.

The ORCA method has a number of notations to support both intrinsic and extrinsic modelling. These are not described in this paper, which concentrates on the concepts and their meta model.