One of my client organisations works on hardware and software design projects related to locomotive design for a manufacturer. They want to adopt the CMMI-DEV and scope their SCAMPI appraisals only for their software projects. Both, hardware and software design projects are undertaken by the same organisation, under the same management, same company name and at the same location. Is it be proper for the organization to exclude the hardware projects from their CMMI journey and appraisals? I feel it is not proper and it violates the principle of institutionalization of processes across the organization. Moreover, if the Lead Appraiser agrees to conduct an appraisal for software projects only, he or she will violate the principle of randomly selecting the projects for the appraisal.
The way I look at this situation depends upon on how the company is organized. If there are separate hardware and software development groups, departments, or divisions that deliver products to a program office (for example), then the software group could be appraised on its own. The same could be true for the hardware group. In fact, this situation occurs quite frequently in my experience here in the United States.
However, if the hardware and software groups are tightly intertwined in building and delivering a product (meaning you cannot separate the two), then I would say that both the hardware and software groups had to be appraised together.
The correct decision requires the Lead Appraiser to have a very good understanding of the organization and its business, as well as being a function of how the organization defines a project and what its process documentation states.