Open Modeling in Multi-Stakeholder Distributed Systems                   <--    ^ 

Robert J. Hall
AT&T Labs Research
180 Park Ave, Bldg 103
Florham Park, NJ 07932
http://www.research.att.com/~hall/

Abstract

Multi-stakeholder distributed systems (MSDSs), wherein the constituent nodes are owned or operated by distinct stakeholders having limited knowledge and possibly conflicting goals, challenge our traditional conception of requirements engineering. MSDSs, such as the Internet email system, networks of web services, and the Internet as a whole, satisfy no globally consistent high-level requirements and, therefore, have behavior which is impossible to validate according to the usual meaning of the term. We can sidestep this issue by changing the problem from "does the system do the right thing" to "will the system do the right thing for me (now)?" To solve that simpler problem, however, we need a way to predict behavior of the system on inputs of interest to us. The OpenModel idea proposes to solve this by establishing open standards for behavioral modeling: each node will provide via http (or through a central registry) a behavioral model expressed in terms of shared domain-specific function/object theories. A tool will support validation by assembling these models and simulating, animating, or formally analyzing the assembled model, helping the user to detect unfavorable behaviors or feature interactions in advance of actually using the real system. While there are clearly scenarios in which the OpenModel approach can't succeed, I believe there are many clear cases (such as Internet email, component reuse, and Enterprise Application Integration) in which it can.

This talk is intended to float the OpenModel proposal and discuss the issues (advantages, challenges, limitations) involved. Please provide feedback.