Quality Control is perhaps not normally thought of as an area in which operational research has any contribution to make; yet, when viewed from the point of balancing inspection costs against costs of allowing defective items into the production process, it is in the mould of a typical operational research problem. Quality control is often approached via the repeated hypothesis test of classical statistics, whereby we may discuss the cost of errors of types I and II and the need to balance these costs in any inspection scheme can be discussed.