ABSTRACT
Developing a cost estimate using PCEs or analogies based on past systems can be tricky. Analysts who attempt to develop such estimates find that the sum of the most likely costs of the components of a system in development does not equal the most likely cost of the entire system, because costs, software, complexity, and so forth do not scale linearly. The same holds true when scaling systems up to SoS and enterprises. Any cost engineer will tell you that we can cost hardware and software separately with some confidence; however, when we integrate and develop interfaces, we simply do not know how to estimate these costs, much less scale to the larger, software-centric systems. This is the challenge of costing systems.
