Experiences in Developing Time-Critical Systems - The Case Study "Production Cell"
This work addresses the challenge of formal verification in time-critical systems for software and mechanical engineering, though it appears incremental as it builds on existing deductive synthesis methods.
The authors tackled the problem of developing a verified control system for a toy production cell by creating a formal specification from informal requirements and using deductive program synthesis to generate a verified TTL-like circuit. They achieved a specification that covers both software and mechanical aspects, allowing reasoning across engineering domains.
Starting from an informal requirements description of a toy production cell used in an intra-project competition in 1994, we give a formal specification that is as close as possible to requirements. We use the deductive program synthesis approach by Manna and Waldinger (1980) to obtain a verified TTL-like circuitery to control the cell. The formal specification also covers mechanical aspects and thus allows to reason not only about software issues but also about issues of mechanical engineering. Besides an approach confined to first order predicate logic with explicit, continuous time, an attempt is presented to employ application specific user-defined logical operators to get a more concise specification as well as proof.