Implementability of Message Sequence Charts

In [1], we have introduced an approach for the generation of SDL process specifications from a basic MSC. The translation is constrained by the provided architecture for the system. We extended our approach to handle inline constructs such as alt, opt, seq, etc. We came across the problem of non-implementability of MSCs for given architectures. This paper focuses on the implementability issue. We illustrate this problem with examples and discuss the notion of implementability of a MSC under a given communication architecture. We will also point out problems with the communication hierarchy introduced in [2] when full MSC'96 is taken into consideration.