Monday, November 8, 2010
Modeling and Simulation Plan - Modeling and simulation should be an integral part of the development of complex systems. The DoD SEF handbook defines a model as a physical, mathematical, or logical representation of something and a simulation as the implementation of a model over time. The DoD SEF has an excellent discussion of modeling and simulation so there is no need to discuss it in detail here. But it is important to stress developing a modeling and simulation plan as part of the overall project planning process.
It can take considerable time to create or tailor models and simulations to a projects needs and to validate their performance. The robustness of requirements analysis, the first step in systems engineering after planning a project, is dependent on the quality of models and simulations available to aid in flowing down requirements to system functions. Thus it’s important to plan the modeling and simulations as early as possible. Decisions must be made up front on the scope of intended modeling and simulation so that work won’t be wasted on models or simulations that won’t be used. The following list can serve to aid in identifying potentially needed models and simulations:
· System and subsystem performance analysis (typically using models initially)
· System and subsystem trade studies
· Design analyses
· System performance simulation
· Subsystem test support (hardware in loop testing)
· System integration support
· System test support
· Support of integration and test with customer systems (If system is part of a larger system)
· Support to training and/or logistics
· Trouble shooting during the systems operational life
In general, the use of validated models and simulations is highly cost effective because of improving system performance and quality and reducing testing requirements. A case in point is the aerodynamic analysis that has dramatically reduced the cost formally associated with extensive wind tunnel testing of aircraft. Also, in some cases modeling or simulation is the only way to validate performance. An example is a system that supplies measurements that are input to a software algorithm developed by a customer or another supplier and the customer specifies system performance on the basis of the output of the algorithm. If the algorithm isn’t available to the system developer then modeling or simulation is the only way the customer’s performance specification can be verified.
Models and simulations are so important to the development of complex systems that an enterprise’s modeling and simulation capabilities have become competitive discriminators and therefore warrant investment like other potentially discriminating technologies. Some enterprises specialize in modeling and simulations that apply to many complex systems and thrive by being teammates or subcontractors on development programs. Examples include various phenomenologies like environmental backgrounds and atmospheric propagation for electromagnetic radiation that are involved in the development of modern optical and radio frequency sensors.