Tips to validate, verify software

Staff -- Control Engineering, 5/1/2006

Anaheim, CA—When verifying, validating, and testing software, you need to figure out if the software is regulated or not, how severe a software failure would be, and how much and what type of validations are needed. Above all, "always do the right thing that's going to allow you to sleep at night," recommends David Vogel, president and founder, Intertech Engineering Associates Inc.

The need for improving software design quality is significant, according to U.S. government statistics that Vogel cited. More than 7% of medical device recalls in 1992-98, 7.7%, or 242 of 3,140, were attributed to software failures, says the U.S. Food and Drug Administration. That number is likely higher now, says Vogel, since software's an increasing part of any system. Good news is that engineers already do 90% of what the FDA wants for validating systems that use software, but they may not document validation in such a way as to be appropriate for evidence. He says:

• Develop a configuration management plan to guide and control multiple parallel development activities and ensure proper communications documentation;
• Implement change/version-tracking methodology;
• If you feel like you are wasting your time, you probably are. Let risk analysis guide where to apply limited resources;
• Assign tasks commensurate with experience, but mix people on teams. Pair experience with those with fresh eyes and fewer assumptions; and
• Find defects earlier in the process to keep costs low. An Intertech Engineering assessment on one project quantified cost of fixing a design phase defect at $17 each and a final testing phase defect at $1,700 each.

Vogel made his comments in conference sessions covering software verification and validation for quality, design, development, and manufacturing systems at Medical Design & Manufacturing West 2006.