From Public Views to Private Views – Correctness-by-Design for Services

Abstract

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.

Specification and verification of harmonized business-process collaborations

“…This equivalence is based on the idea that a superprocess and a refined subprocess have the same (observable) behaviour. Concretely, branching bisimilarity (van Glabbeek and Weijland 1996) is such an equivalence.…”

Assessing service protocol adaptability based on protocol reduction and graph search

“…As we have applied the Sequence reduction rule before we deal with Flow blocks, the Sequence of virtual activities in each branch cannot be folded any longer. For virtual activities in different branches of Flw, they are neither control nor data dependent on each other [20,35], and can be executed concurrently. Therefore, we fold the first virtual activities in all branches of Flw into a virtual activity, and the second virtual activities in all branches of Flw into another virtual activity, and so on.…”

Synthesising implicit contracts

“…Process calculi (e.g., [1]) or even petri nets (e.g., [7]) have been used before to model "contracts". However, the term contract is used there in the sense of interface, as way to guarantee services interoperability, but they are not rich enough for other types of contracts because they do not support deontic operators.…”