Specification and Verification of Context-dependent Services

TL;DR

This paper introduces a formal framework for specifying, composing, and verifying context-dependent services using timed automata and model checking, addressing gaps in current service specification approaches.

Contribution

It provides a formal definition of context-dependent service contracts, a composition theory considering multiple factors, and a verification method using UPPAAL.

Findings

Formal definition of context-dependent service contracts

A composition theory considering functional, nonfunctional, legal, and contextual info

Verification of service compositions using model checking with UPPAAL

Abstract

Current approaches for the discovery, specification, and provision of services ignore the relationship between the service contract and the conditions in which the service can guarantee its contract. Moreover, they do not use formal methods for specifying services, contracts, and compositions. Without a formal basis it is not possible to justify through formal verification the correctness conditions for service compositions and the satisfaction of contractual obligations in service provisions. We remedy this situation in this paper. We present a formal definition of services with context-dependent contracts. We define a composition theory of services with context-dependent contracts taking into consideration functional, nonfunctional, legal and contextual information. Finally, we present a formal verification approach that transforms the formal specification of service composition into extended timed automata that can be verified using the model checking tool UPPAAL.