A computer implemented method, system and program product for monitoring operating procedures in a production environment. The method further includes forming distributions of values of the respective attributes from the candidate defects, and selecting a set of the candidate defects that are characterized by respective candidate attribute values that fall in one or more tails of the distributions. A light source is placed in one of the cavities, and a light sensor is placed in the other. For each individual window of the plurality of windows, a blob extraction process is performed to determine a plurality of blobs corresponding to regions within the inspection image having substantially the second luminance value range such that the plurality of blobs correspond to the plurality of pliable objects. The keypad protector is readily replaced upon damage without resort to electronic device manufacturer service.