WESE: A WEB-BASED ENVIRONMENT FOR SYSTEMS ENGINEERING Dhananjai Madhava Rao, Victoria Chernyakhovsky, and Philip A. Wilsey Experimental Computing Laboratory, Cincinnati, OH 45221-0030 {dmadhava,vchernya,paw}@ececs.uc.edu ABSTRACT The design and development of modern systems is complicated by their size and complexity. Furthermore, many complex sys- tems are built using subsystems and components available from third party manufacturers. The diversity of the available com- ponents has made exploration of design alternatives a large task. Simulation plays an important role in the design and verifica- tion and validation (V&V) of these systems. Although numer- ous models for simulation have been developed, their availabil- ity, accessibility, inter-operability, and system validation cou- pled with proprietary information issues, have been cited as pri- mary bottlenecks in their use. To address the issues involved in the modeling and V&V of systems, WESE: A Web-based Envi- ronment for Systems Engineering, has been developed. Using WESE, a developer can explore design alternatives by construct- ing and analyzing system configurations consisting of compo- nents offered by different researchers and manufacturers. WESE also provides a flexible technique to construct formal specifi- cations of the proposed system for V&V purposes. This paper presents issues involved and the on going work in the develop- ment of WESE. 1 INTRODUCTION Many of today’s complex systems are built using subsystems and components available from third party manufacturers (Rao, Radhakrishnan, and Wilsey 1999). The diversity of the available components has made and exploration of design alternatives, a complicated task (Rao, Radhakrishnan, and Wilsey 1999). Com- puter simulation is widely used (Fishwick 1995) to study and analyze complex systems and model development coupled with model validation and verification (V&V) play a large role in sim- ulation studies (Robinson 1997). In spite of their effectiveness, the complexity of model development and model V&V contin- ues to exacerbate the prevalent use of simulations. Some of the dominant issues being: (i) lack of subsystem and design infor- mation for through V&V (Fishwick 1995); (ii) simulation mod- els are often confidential and their use is complicated by pro- prietary information issues (Rao, Radhakrishnan, and Wilsey 1999); (iii) the models may not be portable or inter-operable (Vi- noski 1997); (iv) the models may not be readily available or ac- cessible (Page and Nance 1994) and; (v) validation of the final system model is hard (Robinson 1997). Modeling and verifica- tion of components for a one-time analysis is not economically Support for this work was provided in part by the Defense Advanced Research Projects Agency under contract DABT63–96–C–0055. viable. As a result, design decisions are usually made from ex- perience rather than from a comprehensive study. The world wide web (WWW) provides an excellent in- frastructure for information exchange and large scale simula- tion (Page, Griffin, and Rother 1998). However, the complex interactions between components for modeling and simulation render the raw WWW services insufficient (Page, Griffin, and Rother 1998). Hence, a web-based collaborative environment, to address the issues involved in engineering systems is the “need of the hour”. In an effort to build such a tool, WESE: a Web-based Environment for Systems Engineering was devel- oped. Using the environment, a developer can analyze differ- ent design alternatives involving components from various re- searchers and manufacturers. WESE provides a flexible frame- work to develop formal specifications and verify the designs using mechanized theorem proving. WESE also provides tech- niques to generate different specifications documents such as cost of the system. This paper presents the issues involved and the on going research in the design and development of WESE. In section 2 a brief description on the underlying simulation and formal V&V techniques are presented. The issues involved in the design and development of WESE are illustrated in section 3. The experiments performed with the environment are discussed in Section 4. Concluding remarks with pointers to future work are presented in section 5. 2 BACKGROUND The support for parallel and distributed simulation in the current implementation of WESE is provided by WARPED (Radhakrish- nan, Martin, Chetlur, Rao, and Wilsey 1998). WARPED is an optimistic parallel discrete event simulator. It uses the Time Warp mechanism for synchronization (Radhakrishnan, Martin, Chetlur, Rao, and Wilsey 1998). In WARPED, the logical pro- cesses (LPs) that represent the physical processes being modeled are placed into groups called “clusters”. The clusters represent the operating system level parallel processes. LPs within a clus- ter operate as classical Time Warp processes. Communication between the distributed clusters is achieved using various mes- sage passing libraries (Radhakrishnan, Martin, Chetlur, Rao, and Wilsey 1998). LPs on the same cluster communicate directly with each other without the intervention of the messaging sys- tem. WARPED presents a simple and robust object-oriented ap- plication program interface (API) for model development. Fur- ther details on the design of WARPED and information on its API are available in the literature (Radhakrishnan, Martin, Chetlur, Rao, and Wilsey 1998). Formal methods enable a designer to precisely model aspects Published in the Proceedings of the 2000 Intl. Conference on Web-based Modeling and Simulation, WEBSIM-2000. c 2000, SCS. Personal use of this material is permitted. However, permission to reprint or republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the SCS.