Building simulators for aerospace applications: processes, techniques, choices and pitfalls

Aerospace engineers and scientists frequently need to employ modeling and simulation as a technique for solving problems. Most of the time, ad hoc processes are used to build a simulator quickly and get results. The purpose of this paper is to provide an overview of processes, techniques and choices associated with constructing simulators within the context of aerospace program development. The overall process described includes developing objectives and requirements, selecting the right tools for the job. Developing the simulator and managing simulator development projects. The process of generating requirements is presented as a series of questions which simulator developers should ask themselves while defining a project. Selecting the right tools to do the job involves cataloging current capabilities, deciding what can be re-used or modified, what COTS/GOTS can be employed, and what new software needs to be built. Simulation development processes are described along with design, implementation and testing options. The section on project management discusses pitfalls, the "triple constraint" (functionality, schedule and cost), the importance of documentation, verification & validation, and long-term maintenance and enhancement. Checklists of steps to take and "rules to simulate by" are provided. The emphasis is on simulator design and implementation, rather than simulator use, although the required use drives the design. This paper attempts to bring together in one place a fairly complete set of useful information about building simulators.