This paper is concerned with compositional specification of services using UML 2 collaborations, activity and interaction diagrams. It addresses the problem of realizability: given a global specification, can we construct a set of communicating state machines whose joint behavior is precisely the specified one? We approach the problem by looking at how collaboration behaviors may be composed using UML activity diagrams. We classify realizability problems from the point of view of each composition operator, and discuss their nature and possible solutions. This brings a new look at already known problems: we show that given some conditions, collaboration level, without needing to look into detailed interactions. 1.

This paper is concerned with bridging the gap between requirements and distributed systems. Requirements are defined as basic message sequence charts (MSCs) specifying positive and negative scenarios. Communicating finite-state machines (CFMs), i.e., finite automata that communicate via FIFO buffers, act as system realizations. The key contribution is a generalization of Angluin’s learning algorithm for synthesizing CFMs from MSCs. This approach is exact—the resulting CFM precisely accepts the set of positive scenarions and rejects all negative ones—and yields fully asynchronous implementations. The paper investigates for which classes of MSC languages CFMs can be learned, presents an optimization technique for learning partial orders, and provides substantial empirical evidence indicating the practical feasibility of the approach.

Abstract. Zielonka’s theorem shows that each regular set of Mazurkiewicz traces can be implemented as a system of synchronized processes provided with some distributed control structure called an asynchronous automaton. This paper gives a new algorithm for the synthesis of a non-deterministic asynchronous automaton from a regular Mazurkiewicz trace language. Our approach is based on an unfolding procedure that improves the complexity of Zielonka’s and Pighizzini’s techniques: Our construction is polynomial in terms of the number of states but still double-exponential in the size of the alphabet. As opposed to Métivier’s work, our algorithm does not restrict to acyclic dependence alphabets.

Abstract This paper considers compositional specifications of services using UML 2 collaborations, activity and interaction diagrams, and addresses the realizability problem for such specifications: given a global specification, can we construct a set of communicating system components whose joint behavior is precisely the specified global behavior? We approach the problem by looking at how the sequencing of collaborations and local actions may be described using UML activity diagrams. We identify the realizability problems for each of the sequencing operators, such as strong and weak sequence, choice of alternatives, loops, and concurrency. The nature of these realizability problems and possible solutions are discussed. This brings a new look at already level, without looking at the detailed interactions of the collaborations, provided that we know the components that initiate and terminate the different collaborations. Keywords service composition, compositional specification of collaborations, realizability of distributed implementations, distributed system design, design guidelines, deriving component behavior from global specifications, workflow for collaborations, UML activity diagrams, service oriented architecture 1