Functional safety and system security in automation systems - a life cycle model

Industrial and building automation systems are more and more important in industry and buildings. New services and novel fields of application call for dependable systems. Two very important properties of such a system are functional safety and system security. In the opposite of todaypsilas development where safety and security are treated separately, investigating security together with safety leads to a reduction of effort in the different phases of system life. That is because they have some similar objectives, but realized by different measures. The intention of the paper is to present a way of developing a safe and secure system as well as to show the associated benefit with special focus on building automation.