ODAY, the usual case is specialization among the members of HIL teams, in other words, the division of tasks. There are tasks to design the electrical aspects of a simulator (HIL hardware, connecting real and substitute loads, cable harnesses), others to model the I/O and plant, and other to create and execute tests. Thus, today’s HIL technology must enable different team members to work simultaneously on different tasks in the same project. For example, while one team member is setting up the I/O configuration of the HIL system another team member is setting up the plant model. This separation of tasks also supports confidentiality, if required. Another key factor for today’s HIL systems is the total cost of ownership, due to tight budgets and tough competition. This is especially true in the context of the ambitious technical requirements named above. A HIL simulator needs to flexible and quickly adaptable to new demands. This applies both to the hardware and to the necessary configuration software.

Other factors such as flexibility and adaptability also come into play. Flexibility is necessary so that different control units or variants can be tested on a single system, either individually or in a network. This is particularity important when entire vehicle electronics are tested because HIL systems often have to be specified and set up at a stage when parts of the final ECU specifications might still be changed. Adaptability is needed because the HIL system must be able to handle executing any additional tests for new components added to an existing vehicle (airplane, satellite, etc.). In addition, when one project has been successfully finished, it is becoming more and more common to reduce overall costs by completely converting the systems in order to test the next project. Finally, a HIL system is often used for network testing as well as for dedicated tests of single components: This occurs when a section of a HIL tester has to be isolated to intensify troubleshooting for a single ECU, and when the component testers are interconnected after successful component tests so that network tests can be run.