Medicaid Management Information Systems (MMIS) are some of (if not the) largest and most complex systems states have to deal with. We’ve been around long enough to know they need to be replaced every 10 to 15 years and are costly to develop. What most states don’t know is when developing systems of this size the bulk of the work goes into removing defects, problems that keep the system from functioning as it should. The graph below is based on information from Capers Jones (from his book “Applied Software Measurement”) for MMIS sized systems.
The graph shows most of the effort in large system development goes into removing defects. Defects can occur in the feasibility, requirements, analysis, design, and coding phases of a project. The sooner a defect is detected in the development life cycle the less expensive it is to correct. So, defects detected in requirements are relatively inexpensive to correct whereas a defect in code is significantly more expensive to correct. Once a system is in operation defects are very expensive to correct. Think about it: not only do you have to fix the code but potentially you fix documentation, retrain users, etc.
So this all begs the question – where do you put your effort and resources during the development of a large system like an MMIS? Focus on quality early (rather than waiting for the testing phase of a project) saves money. A modest investment in quality assurance or independent validation and verification up front results in real dollar savings down the road.