Using extensible modeling in systems engineering and architectural search

The system architecting process is the hierarchical reduction of ambiguity associated with user needs and system design. Design allocation, and subsequent integration, implicitly requires a mechanism by which levels of detail can be added and removed from a decision scenario. This paper addresses the idea of engineering model sharing through the concept of vertical and horizontal extensibility as one mechanism by which hierarchical reduction in ambiguity can be facilitated. Extensible modeling introduces a systems architecting approach to the modeling community by identifying model interfaces and carefully decomposing the model domain. While the actual system hardware is not known at the time of initial design, performance sensitivities can be explored and formally communicated back to the system architect by determining membership in a fuzzy performance metric such as an architectural safety factor. This paper uses a notional vehicle mounted wireless communication system to illustrate the importance of considering environmental coupling variables through the use of extensible modeling and illustrates how fuzzy thinking can communicate the sensitivity of a system design.