We introduce the concept of an operating guideline for an arbitrary finite-state service P , extending the work of [1, 2] which was restricted to acyclic services. An operating guideline gives complete information about how to correctly (in this paper: deadlock-free) communicate with P. It can further be executed or used for service discovery. An operating guideline for P is a particular service S that is enriched with annotations. S communicates deadlock-free with P and is able to simulate every other service that communicates deadlock-free with P. The attached annotations give complete information about whether or not a simulated service is deadlock-free, too.

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Deciding whether a service S can be substituted by another service S is an important problem in practice and one of the research challenges in service-oriented computing. In this paper, we define three substitutability notions for services. Accordance specifies that S cooperates with at least the environments that S cooperates with. S and S are equivalent if they cooperate with the same environments. To guarantee that S cooperates with a fixed subset of environments that S cooperates with, the notion of deprecation can be used. For each substitutability notion we present a decision algorithm. To this end we apply the concept of an operating guideline of a service as an abstract representation of all environments the service cooperates with.

This paper addresses the problem of analyzing the interaction between BPEL processes. We present a technology chain that starts out with a BPEL process and transforms it into a Petri net model. On the model we decide controllability of the process (the existence of a partner process, such that both can interact properly) and compute its operating guideline (a characterization of all properly interacting partner processes). A case study demonstrates the value of this technology chain.

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Abstract. Service orientation is a means for integrating across diverse systems. Each resource, whether an application, system, or trading partner, can be accessed as a service. The resulting architecture, often referred to as SOA, has been an important enabler for interorganizational processes. Apart from technological issues that need to be addressed, it is important that all parties involved in such processes agree on the "rules of engagement". Therefore, we propose to use a contract that specifies the composition of the public views of all participating parties. Each party may then implement its part of the contract such that the implementation (i.e., the private view ) accords with the contract. In this paper, we define a suitable notion of accordance inspired by the asynchronous nature of services. Moreover, we present several transformation rules for incrementally building a private view such that accordance with the contract is guaranteed by construction. These rules include adding internal tasks as well as the reordering of messages and are therefore much more powerful than existing correctness-preserving transformation rules.

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Recently, we introduced the concept of an operating guideline of a service as a structure that characterizes all its properly interacting partner services. The hitherto considered correctness criterion is deadlock freedom of the composition of both services. In practice, there are intended and unintended deadlock-freely interacting partners of a service. In this paper, we provide a formal approach to express intended and unintended behavior as behavioral constraints. With such a constraint, unintended partners can be "filtered" yielding a customized operating guideline. Customized operating guidelines can be applied to validate a service and for service discovery.