Sharing ideas: the SEMSPLC project

By bringing together software engineers from a wide range of specialisms, a government-supported project is set to produce workable standards for safety-critical PLC software. The software engineering methods for safe programmable logic controllers (SEMSPLC) project was conceived with the aim of solving difficulties in an industrial domain, through experience gained in higher-technology sectors. In practice, the anticipated technology transfer could not take place until understanding of the different viewpoints of the many different partners could be achieved. In many instances the apparently lower-technology areas were found to be working effectively within constraints which more theoretical approaches cannot yet address. The challenge for the project, therefore, was to find both a means to structure the sharing of information, and to reconcile the technology viewpoints, to the benefit of all partners. The authors discuss the requirements of the project, the approach taken, the design, analysis and testing of the PLC software, and its benefits