Fixing parts for assembly

A plant produces domestic consumer goods. The production process involves the assembly of parts and subassemblies. The parts are either obtained from sources within the company or purchased from outside suppliers. Parts in the latter category include fixing parts such as screws, nuts and washers. The fixing parts store contains about 500 different articles, varying in price from 0.005p to 0.05p each. The total monthly turnover is about £20 000. Despite the fact that the fixing materials are obtained from many different suppliers, there is no appreciable difference in the lead times of the various articles.