A lower bound on web services composition

TL;DR

This paper establishes an EXPTIME lower bound for the problem of determining whether a web service can be constructed from a set of services, modeled as finite state machines, matching the known upper bound.

Contribution

It provides a tight complexity bound for web service composition problems, including more complex models like the Roman model.

Findings

EXPTIME lower bound for web service composition

Matching known upper bound, confirming problem's computational difficulty

Applicable to richer web service models such as the Roman model

Abstract

A web service is modeled here as a finite state machine. A composition problem for web services is to decide if a given web service can be constructed from a given set of web services; where the construction is understood as a simulation of the specification by a fully asynchronous product of the given services. We show an EXPTIME-lower bound for this problem, thus matching the known upper bound. Our result also applies to richer models of web services, such as the Roman model.