Language support for the specification and development of composite systems

Abstract

S. FEATHER .USC/lnformation Sciences Institute When a complex system is to be realized as a combination of interacting components, development of those components should commence from a specification of the behavior required of the composite system. A separate specification should be used to describe the decomposition of that system into components The first phase of implementation from a specification in this style is the derivation of the individual component behaviors implied by these specifications.The virtues of this approach to specification are expounded, and specification language features that are supportive of it are presented. It is shown how these are incorporated in the specification language Gist, which our group has developed. These issues are illustrated in a development of a controller for elevators serving passengers in a multistory building.

System safety as an emergent property in composite systems

“…Formal reasoning about specification of composite systems was introduced in [11]. Component behavior specifications were derived by pruning (eliminating behaviors which violate a constraint) and decomposing constraints to assign to agents.…”

La especificación formal en contexto: actual y futuro

“…En el desarrollo de las soluciones, los conceptos en términos de qué problemas tienen que ser estructurados y formalizados se tratan a nivel de programación (con mayor frecuencia datos y operaciones), pero las exigencias actuales obligan a elevar el nivel de abstracción y la riqueza conceptual encontrada en los documentos de requisitos informales, como los objetivos y sus refinamientos, los agentes y sus responsabilidades, las alternativas, y así sucesivamente [80][81].…”

Agent orientation as a modelling paradigm

“…The KAOS framework (Dardenne 1993, van Lamsweerde 2000 offers a methodical approach for goal-oriented requirements engineering. The agent is an essential construct, following the earlier work on Composite Systems Design (Feather 1987, Feather et al 1991. The formal framework provides a strong foundation for goal-based reasoning and analysis in agentoriented modelling.…”