Software systems built from reusable components present an attractive vision to software engineers but, in practice, components rarely match the needs of an application, necessitating manual modification and reverification. The work reported in this paper contributes to the goal of machine-assisted resolution of behavioral mismatches, by supporting the generation of adaptors that coordinate and mediate between components, resolving mismatches caused by inconsistent message naming or ordering, or a lack of correspondence between messages at component interfaces.

Rigor and expressiveness of component interface languages have an effect on the extent of the mismatch resolution that can be accomplished, so the authors take a formal approach. Component behavioral interfaces are expressed using labeled transition systems (LTSs)--a software system contains a behavioral mismatch if the synchronous product of its component LTSs contains a deadlock. The paper offers two algorithms for adaptor construction: one using synchronous vectors, and one using a more sophisticated Petri net-based analysis that has higher computational cost but allows mismatches between message transmission and reception ordering to be resolved. A tool embodying the algorithms is described, and the approach is illustrated by reference to a series of increasingly demanding examples.

The paper is directed at specialists, but the clear structure and comprehensive review of related work make its main contributions accessible to the general reader. Further work is required to integrate the approach into a development methodology, but it represents a useful contribution to bridging the gap between the promise and the reality of component-based software engineering.