Software Engineering Institute

The practical, pragmatic benefits of building early architectural models of the embedded computing resources for Cyber-Physical Systems (CPS) have been documented and demonstrated. However, the rate of adoption of this practice by the contractor community has been slow. Empirically, we have observed skepticism with respect to the increased cost of building these models, as being of sufficient value to justify their expense. This paper elaborates the reasons why using traditional methods, such as return on investment (ROI), to justify the increased expense (of building and maintaining these virtual models) is inadequate. Alternate ways to quantify and rationalize the benefits are discussed, but ultimately the decision to adopt may require a leap of faith.

We begin by describing the problem space and advancements in the design and implementation of the embedded computing resources for CPS. We discuss the proposed process change we seek: using model-based methods to reduce integration and test risk. We discuss the potential effects of that change on CPS, as well as our thoughts on ROI and the issues that can arise when using ROI. Finally, we recommend how organizations can move forward with a model-based approach in the absence of solid ROI data.