Testable and diagnosable commercial off the shelf (COTS) electronics

Commercial off the shelf (COTS) are inexpensive electronics modules, partly because the designs are expected to conform to commercial needs and driven by market popularity, rather than military and avionics logistics. Design for testability (DFT) and for diagnosability (DFD) can serve both manufacturing and end user concerns. COTS testability, however, are generally focused only on improving manufacturing test - or the vendors' domain. End users' testability and diagnosability concerns are different. For COTS to serve system level support, designers must plan for maintenance and repair paradigms. We present a set of general and simple to implement guidelines for COTS designers so that system designers can create testable and diagnosable systems using COTS modules. The guidelines will initially serve as selection criteria between competing COTS, but we hope it will eventually become a universal design guideline for all COTS designers.