I can create test cases in order to simplify your testing process. As a user who does not know a lot about the product or the application itself (from a black box testing perspective), this would make it much for easier to create functional test cases based on what i expect the product to do, according to a given set of requirements. Performance testing for websites can also be made by using a load generator such as Apache JMeter to check how the server's website behaves under massive numbers of users simulating different actions in the GUI. Testing applications can also be done by creating a virtual machine in which i can install the application and perform requirement checks on it to discover if there are functionality issues, faulty operations, or performance issues. Testing for the automotive/electrical domains would require an electrical diagram, if not, at least a document in which the behavior of the system is described so that i can create a couple of ideas on what can be tested from a user's perspective.