Topologically configurable systems as product families

We address a category of systems whose deployment requires a configuration according to topological information. Although inspired by the case of railway interlocking systems, we give a general definition of topologically configurable control systems. We consider the application of product line engineering principles to the development of these systems, by discussing the adoption of different approaches to achieve a flexible configuration of products, able to factorise most of the design effort, as typical in a product line approach. Verifying the behaviour of such systems, either by testing or by formal verification is actually a challenge: the intricate relations between the actual topology controlled by a product and its functional requirements may prevent any attempt to factorise analysis activities. We will discuss how the application of product line engineering principles can help, with special focus on formal verification, pointing to several open research issues.