Medical software testing is extra important.
Developing software is a risky business. That’s why so many software support and testing companies exist. For most industries, it’s an unregulated activity. You can basically develop software any way you like.
In the medical device business, however, there are stringent FDA software validation guidelines. These guidelines help steer medical device manufacturers in the processes and techniques they use to build high quality software. As you can imagine, having a software failure in an implantable medical device is undesirable, to say the least, for both the patient and the manufacturer.
According to FDA reports, between 1992 and 1998, 7.7 percent of medical device product recalls were attributable to software failures. Of these failures, 79 percent were caused by software problems that occurred as a result of software changes after the initial product was released. This implies that there are process issues that must be addressed when updating software. This is also a major area of concern in the larger software development industry.
Software, by nature, is designed to be upgraded and enhanced over time. While this is certainly a major advantage of this technology, it can also be a massive liability. If solid development and change processes are not in place, or are not accurately followed, errors are likely to surface at a later date, as evidenced by the FDA numbers and data from a host of other non-medical software projects.
The FDA knows that implementing a few fundamental best practices is the key to consistently developing high quality, reliable software. One of the principle tenets of world-class software development is that you cannot “test quality into” the software after it’s built. Most testing will only find defects, and while this is entirely necessary, more testing needs to be done up front to actually prevent defects in the first place.
There are several proven steps that can and should be taken by all software manufacturers to prevent defects and deliver higher quality software products:
Quality planning from the outset: Good quality doesn’t just happen. It needs to be planned. This includes buy-in from relevant stakeholders up front, with a documented plan that requires signatures from these key stakeholders.
Thorough documentation of all software requirements: The key to all good software development is to start with great requirements. They must be both specific and testable.
Design and code reviews with peers and business line owners: This is an area that many times is overlooked, but the benefits gained for the amount of time spent can be significant.
Ironclad change management: Having a well-defined testing process for setting new feature priorities is critical. The method I prefer is to weigh the business benefits against the technical complexity of the feature, coupled with costs and timelines. A big part of change management is keeping control of schedules. Remember that every new feature must have requirements defined–designed, coded, tested and integrated with other features appropriately. In many cases it can be very difficult to even add what seems to be a simple new feature.
Get a commitment from senior management to deliver high quality software: If you don’t have real backing, then all of these points are probably meaningless.
In the long run, software manufacturers that follow these principles will actually cut costs and improve their product. That is why the FDA mandates certain processes and controls. There is plenty of public data available, from the Software Engineering Institute at Carnegie Melon University, for example, to support the claims of cost savings from strict adherence to proven software quality processes.
It’s never really been about having the necessary knowledge to build software correctly, but figuring out how to institutionalize it within the organization in an effective way. This is where independent software quality firms offer an advantage by leveraging their independence and experience to rally development groups and management to embrace the quality processes and tools they need to be successful.
If more software organizations adopted the general approaches defined by the FDA for medical device manufacturers, there would be far fewer software horror stories making headlines. These organizations would also save time and money on recalls and customer support. And, of course, the goodwill they earn with their customers is immeasurable.
John R. Fox is vice president of SWAT Solutions ([email protected]).