Logic versus magic in critical systems

A prevailing trend in software engineering is the use of tools which apparently simplify the problem to be solved often, however, this results in complexity being concealed or ''magicked away''. For the most critical of systems, where a credible case for safety and integrity must be made prior to there being any service experience, we cannot tolerate concealed complexity and must be able to reason logically about the behaviour of the system. The paper draws on real-life project experience to identify some historical and current magics and their effect on high-integrity software development: this is contrasted with the cost and quality benefits that can be made from taking a more logical and disciplined approach.