Infrared focal plane array (IRFPA) specifications can drive IRFPA cost and yield. Specifically, IRFPA operability affects IRFPA producibility in two ways, each having an opposite impact. Operability improvements resulting from purer, more perfect materials (i.e., fewer defects) become increasingly difficult to achieve as the operability approaches 100%. Thus, yielded IRFPA material costs increase with an increasing operability specification. On the other hand, IRFPAs with higher operability have a greater probability of meeting system specifications for defective pixels, and thus fmal test yields are better. This effect tends to reduce IRFPA cost as operability increases. This paper reports on efforts to quantify the latter effect. The defect specification is examined through the development and exercise of two computer models. The first is a Monte Carlo simulation to predict the probability that an IRFPA will meet system global and local defective pixel specifications as a function of operability. The second is a manufacturing cost model exercised to determine the cost impact of the "pixel yield." Model output is presented for two IRFPA configurations and for various defect specifications. For each case, relationships are determined for the probability of passing the defect specification versus operability and for (normalized) cost versus operability. The analysis shows that pixel defect specifications can become severe cost drivers for larger arrays. However, even slight relaxation of specifications can be very beneficial in increasing array producibility and reducing IRFPA cost.