• (CASE), and computer-aided manufacturing (CAM) in the design of the 777) would help the Navy to stay even with rapidly changing threats, technologies, priorities, and budgets.
• The building of a fully autonomous undersea or air vehicle to perform one mission with reasonable generality.

Desirable research objectives in this area are as follows:

• Short term—Integration of discrete, continuous, and symbolic representations of models.
• Midterm—Validation of internal consistency and completeness and against external specifications; representation and explanation of complex models to humans; and computation-constrained, satisfactorily approximate solutions based on dynamic, variable-resolution models controlled by metamodels.
• Long term—Global optimization across complex models; and very high level languages for system design (including decision-support software) and theory of model design.

Types of ongoing research activities in this area and organizations involved are as follows:

• Knowledge representation activities—Stanford University and Carnegie Mellon University,
• Simulation/modeling activities—Bolt, Beranek and Newman Laboratories,
• Software engineering activities—Defense Advanced Research Projects Agency (DARPA) knowledge-based systems application (KBSA) centers, Kestrel Institute, University of Southern California (USC)/ISI, Stanford University, Carnegie Mellon University, and Harvard University, and
• Hardware computer-aided design (CAD) activities—DARPA centers, Stanford University, and Carnegie Mellon University.

The necessary ingredients for research in this area are summarized below:

• Skills—Expert systems, simulation and modeling, automated software design and synthesis, computer-aided design, and human physiology.
• Facilities—Major computational resources to execute and validate complex models: distributed workstations plus parallel computer available over the network could suffice.
• Cooperation opportunities—Multiple groups must collaborate to model complex systems (e.g., a ship) because the expertise never resides totally in one organization. Two or more research groups could collaborate by modeling different subsystems of a problem.
• Level of effort—For small, theoretical tasks, one person could make progress; large, demonstration-oriented tasks would require a group of at least five, for example, one engineering system researcher, one simulation/modeling researcher, one application expert, one knowledge engineer, and one programmer.

Collaboration or group work is generally described as a social process used to more effectively perform tasks. These tasks include problem solving, idea generation, decision making, and conflict resolution. Collaboration includes both formal and informal methods. Formal methods can be characterized as structured collaboration sessions with