A verification-supported evolution approach to assist software application engineers in industrial factory automation

Automated production systems (aPS) are complex systems with high reliability standards which can - besides through traditional testing - be ensured by verification using formal methods. In this paper we present a development process for aPS software supported by efficient formal techniques with easy-to-use specification formalisms to increase applicability in the aPS engineering domain. Our approach is tailored to the development of evolving aPS as existing behavior of earlier revisions is reused as specification for the verification. The approach covers three verification phases: regression verification, verification of critical interlock invariants and delta specification and verification. The approach is designed to be comprehensible by aPS software engineers: Two practically applicable specification means are presented. Formal methods have not yet been widely adapted in industrial aPS development since they lack (a) scalability, and (b) concise and comprehensible specification means. This paper shows concepts how to tackle both issues by referring to existing behavior during evolution verification to advance towards the goal of applicability in the aPS engineering domain. A laboratory case study demonstrates the feasibility and performance of the approach and shows promising results.