A robust design is one which makes the system work as desired under variations arising from the environment, production and wear in use. The goal of robust design activities is to improve the quality of a product by minimizing the transmitted effects of the causes of these variations without requiring the causes to be acted upon. An alternate definition proposed by Clausing is that a robust design is one in which the system operates as close as possible to the ideal function or as far as possible from the possible failure modes. This leads to the concept of Operating Window, which Clausing and Frey define as the region in noise parameter space that avoids failure modes and is bounded by significant parameters at which certain failure modes are excited. This concept of operating window is relatively new in the robust design literature and few examples of possible applications of the technique have been published. Application of this principle to Electrophotography, and in particular, the fusing process, represents a good example of its use. This paper present the work completed to date to apply the operating window concept on the offset failures bounded by hot and cold offset in order to demonstrate the utility of the Operating Window method.