by Gurney Thompson
| January 7, 2015
We’re often asked about how to model the cost impacts of various quality assurance standards like SEI Capability Maturity Model (CMM) and CMM-I for software, DO-178c and DO-254 for airborne software and electronics, various MilSpecs, and even process standards like ISO-9000. As a result, we’re kicking off a study to create new and updated modeling guidance for use with our cost models.
Many of these standards have significant overlap, and an implementation of one can give you a head start in implementing another. For example, DO-178c and DO-254 are design assurance standards, which basically says that if you follow these development processes, you can be assured that the product will perform reliably and as intended by the design. CMM does this too and uses many similar processes, but extends it to look at the management and refinement of these processes as well.
These standards are quite a bit different from ISO-9000, though. While CMM, DO-178 and DO-254 are product-focused, ISO-9000 is more process-focused and deals with documentation, repeatability, and consistency. In theory, you can build a high quality DO-178 or DO-254 certified product in a chaotic, disorganized organization. You can also build extremely consistent garbage in an orderly organization closely following ISO-9000.
Each of these standards can have different impacts on cost and schedule estimation. First, there may be training costs, costs of new tools, and costs to get your product or organization independently certified. Then, you may be performing activities you weren’t before such as tracking new information, new approaches to testing, more stringent reviews, etc. These can greatly increase cost and schedule, especially for inexperienced teams, but, in some cases, they can actually end up reducing costs if they make up for previous inefficiencies. Then finally, there are other impacts like greater reusability and interoperability, and fewer defects.
For the first phase, we’ll focus on the request we’ve seen most frequently lately, which is for DO-178c and DO-254 guidance. These are quality standards for airborne software and electronics, respectively, and these standards are a major reason for the extremely high, continuously improving reliability of modern aircraft. Stay tuned for a blog post on this soon. We would love to focus our research on whatever our users are interested in, so please post a comment if you have any suggestions!