Comma interfaces open the door to reliable high-tech systems

“Our medical devices are growing bigger and bigger,” observes Daan van der Munnik, software manager at Philips Healthcare in Best. “We have to chop them up in smaller subsystems to keep their development manageable, but also for validation purposes. Up to a year ago, we validated a complete device in one go – a huge effort. By chopping it up in smaller subsystems, we can focus our validation efforts on the parts of the system we actually touch for a particular feature. We do need to show that when we put everything together, it still does what it’s supposed to do. Both the disassembling and reassembling call for good interface management.”

Subsystems are also increasingly being farmed out to subcontractors. “We’re really moving to a system-of-systems development, where we make some parts ourselves and some parts come from outside,” notes Van der Munnik. “For instance, in one of our image-guided therapy systems, we have three types of patient tables. One is developed by us, two are made by other companies. From a user perspective, however, they all have to appear to be an integral part of the system – the user experience, for instance when moving or tilting, has to be exactly the same. This means that, for our subcontractors, the interfaces need to be clearly defined, both on a low technical level and a high subsystem level.”