Consumers always seem to want more features, better reliability, and increased value. Regulations seem to grow ever more detailed and competitors are constantly raising the stakes by implementing new innovations. This coupled with the fact that automotive manufacturers are constantly trying to reduce cost and weight of the vehicle, makes the task of designing a vehicle even more challenging. One of the major contributors to the vehicles cost and weight is the electrical/electronics system. Designing a vehicle's electrical/electronic system is a complex task with many constraints (e.g., cost, timing, manufacturing, assembly, weight, quality, reliability, serviceability, industry standards, brand image, etc). Analyzing and understanding all of these constraints and alternatives is how the vehicle's electrical/electronic system should be designed. In this paper, the constraints that need to be considered when designing a vehicle's electrical/electronic system will be discussed.