Safety analysis of mechatronic product lines

Abstract

Most methodologies for the design and analysis of mechatronic systems target a single product. From a business perspective, successful product development requires shortening development times, reducing engineering costs and offering a greater variety of product options for customers. In software engineering, the software product line (SPL) technology has been developed to meet these conflicting goals, and several major companies have reported success stories resulting from SPL adoption. In mechanical engineering, similar methodologies have been developed under the name of product platforms. Methodologies for analyzing product qualities such as safety or reliability have been introduced for both SPL and product platforms. The problem with these methodologies is that they consider either software or mechanical product design, so they do not guide developers to find the best balance between the controller and the equipment to be controlled. Several system properties of a mechatronic product line should be investigated with mechatronic analysis methodologies before the development process branches to software, electronic and mechanical design. In particular, safety is one system property that can only be analyzed by considering both the equipment and its controller, so mechatronic methodologies early in the design are advantageous for discovering safety-related design constraints before costly design commitments are made. This paper extends the Functional Failure Identification and Propagation (FFIP) framework to the safety analysis of a mechatronic product line with options in software signal connections and equipment. The result of applying FFIP is that unsafe combinations of options are removed from the product line.