Lessons Learned Using COTS in Real-Time Embedded Systems

摘要

It Is certainly not news that the use of commercially-available-off- the-shelf (COTS) hardware and software is revolutionizing the acquisition process for new real time embedded systems. Designs using COTS hardware and software can be the only approach to meeting today's aggressive schedule and cost budgets, while lowering production risks. Using Open Systems is an attractive approach to inexpensively incorporate increased performance as technology improves. It is hard to imagine a program manager who would not want to try to take advantage of these benefits. DOD is not only encouraging, but also mandating the use of COTS hardware and software in the development of new and replacement (sub)systems to meet current budget constraints. However, the use of COTS must be carefully managed or the results of these benefits will disappear into a life cycle maintenance nightmare. There are several lessons that have been learned about the use of COTS that should be considered before planning a new program. The use of Commercial-Off the Shelf (COTS) hardware and software in real-time systems is not new. The author has been involved in developments using COTS in real-time systems since 1983 and he was hardly a pioneer. The use of COTS in real-time systems in the past was limited by technical considerations, operational suitability issues, and life cycle concerns. The lower cost of COTS was always attractive, but for most programs these limitations made its use impractical. The major performance hurdle to using COTS in Command and Control (C2) real-time applications was always that COTS hardware and its shrink-wrapped operating systems were not designed to l;ndle the quantity of interrupts that C2 systems need to process in a timely fashion. As technology developed, it was possible to use intelligent controller cards to solve this technical issue. There were only a handful of vendors who started to design thei.