Machine manufacturers are increasingly making use of safe control systems in order to program safety functions on machines. An essential requirement set out by the relevant standards is that these programs must be developed within a structured work process – the "V model". By their nature, the further provisions in the standards concerning measures for error avoidance during development are also formulated in very general terms. In addition, little has been published in the way of examples and suggestions for implementation of these provisions. Interpretation of the standards during software development in machine construction is therefore often unclear, and leads to difficulties in implementation. This situation led to the launching of a project funded by the DGUV and conducted at the Bonn-Rhine-Sieg University of Applied Sciences (between 2011 and 2013) into standards-compliant development and documentation of safety-related PLC software in machine construction. In the course of the project, a development method suitable for practical application was developed in conjunction with regional machine construction companies.
The first task was to identify the topics of the IFA report, and to formulate a structure based upon them. Interested parties had familiarized themselves with the development method and discussed the content of such an IFA report in two workshops. The concluding report of the DGUV research project and the description of the development method also had to be edited. The project examples were available initially as Excel files, and will also be published in this format for download. The file format and structure of the Excel worksheets was however optimized for automated handling by a software tool. The existing content of the research report was supplemented by new information and interpretations of normative requirements. Further relevant topics had emerged in discussions in past years with parties from the machine construction sector, industry associations and machine test bodies. The draft of the IFA report was reviewed internally and by the original project contractor, the Bonn-Rhine-Sieg University of Applied Sciences, and then submitted for final editing.
IFA Report 1/2015 on safety-related application software for machinery has been completed and is available to interested users online in German in PDF format, together with the revised examples. An English translation is planned. The report describes the "IFA matrix method" for the development of safety-related application software. It also provides additional information on machine safety assured by this application software. The report thus constitutes an important basis for machine and control systems manufacturers for information, consulting and testing. The ten examples provide test bodies and service providers in the sector with comprehensive material for consulting and training. The examples demonstrate possible implementation in practice of the requirements and technologies described in the standard. Interpretation of the standard during software development in machine construction is facilitated. Talks have already been held presenting the IFA matrix method and selected examples. The report refers to the follow-on project (IFA 5136) involving development of the "SOFTEMA" tool. This tool will permit computer-aided application of the IFA matrix method described.
-cross sectoral-Type of hazard:
mechanical hazards, design of work and technologyCatchwords:
safety technology (engineering), machine safety, new technologiesDescription, key words:
application software, machine safety, specification, documentation, software errors, testing of safety-related software, safety-related controls, ISO 13849-1, matrix method