Model-Based Systems Engineering with GENESYS

The Problem

The systems that we develop are usually dynamic. Thus, the system specification should be dynamically consistent and executable at the system level. • Can it be achieved by confirming that the individual subsystems are executable? • NO - Modern Control Theory shows that just having a set of individually executable subsystems does not result in an executable system. • Can we use simulation of the design? • Yes - But common dynamic verification simulators are not exact representations of the system being specified (see next chart) • If not executable, what happens? • Achievement of dynamic consistency is left to integration and test teams, or • The System fails to meet dynamic needs

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How It Is Done Today?

• Give the software and test/simulation team a copy of the preliminary system specification • They interpret it and build software and simulators • If the delivered software and simulator results seem reasonable, it is accepted • Question: Does the simulator team ever return a simulator that does not run? (Answer: not in my experience) • Developers “debug” the simulation until it runs and seems to give reasonable answers • Debugging simulator code often modifies the system concept by accident • Results? • We dynamically verified a system that is different than specified. • Integration and test team must finish the systems engineering

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