Human mismatches in machining

This research highlights human factors issues in machining by examining mismatches in machining tasks and their relationships with various human characteristics. Mismatches refer to incompatibilities, inappropriateness, unsuitabilities or inconsistencies which, if not addressed, would lead to errors. Knowledge of the rate of mismatches and an understanding of the causes is invaluable in the design of new working environments, machines and tasks. The Human Task-Mismatch Matching Method was developed to study these issues in manual turning operations using experimental and questionnaire techniques on groups of 16 skilled and 12 unskilled operators. The skilled subjects were drawn from local industry and university technical staff. Unskilled subjects were engineering students all of whom had some experience and knowledge of machining through periods of industrial placement. With a single group of skilled and unskilled operators statistically significant relationships were established between mismatches and many of the human characteristics studied, but for skilled operators the only significant relationship was between self-confidence and trust. The general conclusion is that whilst studying operators in their own workplace provides invaluable information for the design and operation of future workplaces, the relationships between performance and human characteristics remain difficult to formally establish.