Bridging structural and software design of PLC-based system families

PLC-based systems are commonly designed according to a two-phase process: the system structure is conceived and detailed by the electro-mechanical project team, then the control project team is asked to design and develop the control software. Because of product complexity, different culture of the two teams, lack of supports to requirement specification and communication, and other problems, the design process presents heavy, costs and times. The paper aims at presenting an approach for bridging the gap between the two design environments. It adapts and integrates two techniques resulting from European Union funded projects: a family-based product modelling technique from the ESPRIT project 8224-RUMS (used in the structural design phase) and an object-oriented PLC specification language from the ESPRIT/ESSI project 10542-EASIER (used in the software design phase).