Requirements management lessons learned: fuzzy "most likely" versus clean shaven "not to exceed"
Paul A. A. Lightsey · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2015
Mission objectives often have a level of imprecision that lends itself to a fuzzy logic approach, even though the more traditional approach is to flow down bimodal pass/fail “not to exceed” type of requirements. Examples will be given for large astronomical telescope applications involving optical performance, active wave front and control, and radiometric/stray light controls demonstrating the pros and cons of the two contrasting strategies. This paper provides an overview of lessons learned on different programs and how that information can be used reduce the cost, schedule, and success of future missions.