Project duration: 1 October 1994 to 1 April 1998

Project partner: Philips GmbH Research Laboratories Aachen

Financing by: Philips and DFG

In the CoCoN project, a formal development method for distributed communicating systems from the ESPRIT basic project ProCoS was tested for its applicability in telecommunications. It turned out that not all requirements are known at the beginning of the development of telecommunication systems and that requirements can change during the lifetime of a system. For this reason, the ProCoS method was extended to an incremental development method. The incremental CoCoN method was developed and tested in co-operation with Philips on the basis of three complex case studies from the field of value-added services for intelligent networks.

DFG Leibniz funding made it possible to formalise the ideas developed in collaboration with Philips and expand them into a formally sound method. In the CoCoN approach, requirements are described in trace logic, in which it is possible to draw conclusions about permitted sets of traces. To increase the comprehensibility of the requirements, trace diagrams were developed for the graphical visualisation of trace logic requirements. The formalisation of incremental development is based on the fact that a set of parallel-working, synchronously communicating automata is extended by additional permitted traces of actions. Among other things, the extension takes into account that no new deadlocks are introduced. The results are summarised in the dissertation by S. Kleuker.