Every complex system today is designed using models at various complexity levels. These can be detailed finite element models or more lumped parameter system level models. Models can also be used to describe work-flow and manufacturing systems.
Additionally, most systems today have both hardware and embedded software built in. With the intelligent use of hybrid modeling and simulation, design times and quality escapes can be drastically reduced.
Further, these models can be exploited in developing automated test equipment (ATE) to cut V&V cycle times as well.