Frameworking: a collaborative approach to control systems development

The use of frameworks in software engineering is a common practice to ease the development and maintenance phases. In our terminology, a framework is a set of practices and software components from which a developer can select a subset for his application. Three frameworks are currently in use at CERN for the development of control systems: the JCOP (Joint COntrols Project) Framework, the UNICOS (UNified Industrial COntrol System) Framework and the LHC GCS (Gas Control System) Framework. The three projects originate from different domains, with different requirements and timescales. Still there are many commonalities and considerable effort has been invested in establishing and maintaining a collaboration between the three projects. The paper will talk first about the reasons for a framework based approach. The different Frameworks will then be described, with their domain of applicability, their scope and a short overview of the technical details. Afterwards, the underlying tools will be presented. The relations and dependencies between these Frameworks will be explained. Finally a summary of our experience and some conclusions will be given.