A geographically distributed enterprise simulation system

Sandia National Laboratories has the role of system integrator in the US Department of Energy's Nuclear Weapons Complex (NWC) and the responsibility for maintaining the nuclear stockpile. Maintenance is a complex task that involves a great number of geographically distributed functions, and a variety of analysis tools and models are used to plan operations, assess capabilities and guide political decisions. We are developing a framework for modeling the NWC unde interactive human control. The framework consists of a simulation system whose users and components are distributed across the entire United States. The purpose of the system is to support decisions about questions ranging from low-level operational matters involving only a sub-component of the complex to high-level policy issues requiring simulation of the entire complex. The system integrates multiple domain-specific legacy models and policy models and allows simulation at varying levels of detail. To provide such a framework, we have had to address a number of technical problems, whose solution is the focus of this paper. The three most fundamental problems are to provide geographically distributed, synchronized human participation in the simulation; to provide distributed ownership and security in such a way that the facility hosting a domain-specific model retains all rights to provide or deny a user access to its information; and to integrate legacy models written in a variety of tools or languages and executed on different platforms. Key features of our approach are the use of the Java language and the coordination of the simulation through a new parallel discrete-event simulation system. (C) 2000 Elsevier Science B.V. All rights reserved.