Using coordinated atomic actions to design safety-critical systems: a production cell case study

Coordinated Atomic actions (CA actions) are a unified approach to structuri ng complex concurrent activities and supporting error recovery between mult iple interacting objects in object-oriented systems. This paper explains ho w we have used the CA action concept to design and implement a safety-criti cal application, We have used the Production Cell model that was developed in the Forschungszentrum Informatik (FZI), Karlsruhe, Germany, to present a realistic industry-oriented problem, where safety requirements play a sign ificant role, Our design consists of two levels: the first level deals with the scheduling of CA actions, and the second level deals with the interact ions between devices. Both the scheduling mechanism and the device interact ions are enclosed by CA actions. Exception handling and error recovery are incorporated into CA actions in order to satisfy high safety and fault tole rance requirements. A controlling program based on our design was developed in the Java language and used to drive a graphical simulator provided by t he FZI. Copyright (C) 1999 John Wiley & Sons, Ltd.