In 2002, the National Institute of Standards and Technology estimated that software defects cost the US economy $59.5 billion annually. Although that was 13 years ago, I can only imagine that this number has increased, as the use of software has increased as well. It is well known that in Waterfall methodology, the cost of fixing a defect increases exponentially if the defect is found in the later stages of the project. Since the Agile Manifesto methodology was only developed the year prior to this study, it can be assumed that the number estimated by the NIST is largely based on projects that were developed using a Waterfall methodology. I began to wonder if there have been any studies estimating how the shift towards Agile has affected the annual cost of defects.
There are a lot of white papers and blogs claiming that Agile reduces the cost of quality since it incorporates earlier and more frequent customer feedback, early and continuous integration, and implementation and testing of software in smaller chunks. In order for the claims to be valid, an organization must implement Agile correctly. When we talk to clients or potential clients, however, they describe an Agile-like environment where business sponsors are not included or documentation is completely omitted.
At CTS, we strive to reduce the overall cost of quality by implementing a proactive QA approach, which incorporates QA early in the software cycle, whether it’s Waterfall, Agile, or Hybrid-Agile. We believe there are four foundations to a successful QA process: support from management, adequate time allocated for testing, testable requirements, and a mature change management process. If you have these four foundations combined with QA early in the process, then you can reduce your cost of quality, regardless of the software methodology.