Discrete EVent Specification (DEVS) environments are known to be implemented over middleware systems such as HLA, RMI, CORBA and others. DEVS exhibits concepts of systems theory and modeling and supports capturing the system behavior from the physical and behavioral perspectives. Further, they are implemented using Object-oriented languages like Java and C++. This research work uses the Java platform to implement DEVS over a Service Oriented Architecture (SOA) framework. Called the DEVS/SOA, the framework supports a development and testing environment known as DEVS Unified Process that is built on a model-continuity-based life cycle methodology. DEVS Unified Process allows DEVS-based Modeling and Simulation (M&S) over net-centric platforms using DEVS/SOA. This framework also provides the crucial feature of run-time composability of coupled systems using SOA. We describe the architecture and designs of the both the server and the client. The client application communicates with multiple servers hosting DEVS simulation services. These Simulation services are developed using the proposed symmetrical services architecture wherein the server can act as both a service provider and a service consumer contrary to the unidirectional client-server paradigm. We also discuss how this Services based architecture provides solutions for cross-platform distributed M&S. We demonstrate DEVS/SOA framework with a scenario of Joint Close Air Support specified in Business Process Modeling Notation (BPMN). We also provide a real-world application of Network health monitoring using DEVS/SOA layered architectural framework.

翻译：离散事件系统规范（DEVS）环境通常基于HLA、RMI、CORBA等中间件系统实现。DEVS体现了系统理论与建模的概念，支持从物理和行为视角捕获系统行为。此外，现有实现多采用Java、C++等面向对象语言。本研究利用Java平台，在面向服务体系架构（SOA）框架上实现DEVS。该框架称为DEVS/SOA，其支持基于模型连续性生命周期方法构建的开发测试环境——DEVS统一过程。通过DEVS/SOA，DEVS统一过程可实现基于网络中心平台的DEVS建模与仿真（M&S）。该框架还利用SOA提供了耦合系统运行时可组合性的关键特性。本文阐述了服务器与客户端的架构设计。客户端应用程序可与多个托管DEVS仿真服务的服务器通信。这些仿真服务采用本文提出的对称服务架构开发，其中服务器可同时充当服务提供者与服务消费者，突破了单向客户端-服务器范式。我们还讨论了该服务架构如何为跨平台分布式M&S提供解决方案。通过业务流程建模标注（BPMN）定义的联合近距空中支援场景，我们展示了DEVS/SOA框架的运行机制。此外，本文还提供了基于DEVS/SOA分层架构框架的网络健康监测实际应用案例。