Vehicle electrical systems have become very complex, and contribute to key parameters such as cost and weight. Powerful Commercial Off The Shelf (COTS) tools are available supporting electrical system design & documentation, and harness manufacturing. Several factors influence the decision whether to invest in in-house (proprietary) software development or to adopt COTS tools. Particular characteristics impact this Make Or Buy decision in the electrical domain, including strong needs for flexibility, enterprise integration, and IP protection. COTS tools are rapidly replacing in-house software in the electrical domain. This trend matches what has occurred in similar domains, driven by considerations of economics, innovation, and strategic business focus.