The ideas and findings in this report should not be construed as an official DoD position. It is published in the interest of scientific and technical information exchange.

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The People Capability Maturity Model (P‐ CMM) is an adaptation of the Capability Maturity Model SM for Software (CMM SM) focused on developing the organization's talent. The motivation for the P‐ CMM is to radically improve the ability of software organizations to attract, develop, motivate, organize, and retain the talent needed to steadily improve software development capability. Although being initially developed with a focus on software and information systems development, the principles and many practices of the P‐ CMM apply equally to systems engineering. There is thus on the horizon a family of capability maturity models to help organizations improve their development capability: the CMM for Software, the Systems Engineering CMM (SE‐CMM), and the P‐CMM.

This paper describes a two‐year research effort to define complexity measures for avionics systems in order to help the FAA identify when systems are too complex to be able to assure their safety. The research project developed a measure of complexity related to the number of ways that an avionics system error (fault) could propagate from one element to another. Since each potential propagation requires another sub‐argument in the safety case, the number of such arguments should be proportional to certification effort. Thus, the ability to show that the system is safe, through the certification process, should depend on whether a system has low enough complexity (number of ways for errors to propagate). Our results include a formula for estimating the “error‐propagation complexity” from a system design, the results of using that formula on small and medium systems, and steps for using the formula. The test of the formula was performed by repeating that calculation on a second design for the first system and briefly on a larger design identified by the FAA, from a NASA technical report.