The early English system of manufacturing began with skilful technicians who produced parts or products for a model or from a design. A skilful worker was responsible for producing all the different parts of the design from the beginning to the end product. Both the production quantity and production rate were low. Moreover, this manual production method could not produce exactly identical products when the ordered quantity was more than one. The dimensions of identical parts of the same design varied during the hand production process. As a result of deviations from the manual process, workers were grouped separately in order to produce a minimum number of parts. This minimized the size deviations induced from different workmanship. By using such a decentralized production process, the dimensions of each component part produced became more accurate and closely identical to each other. The fitting of a part to its counterpart was therefore more accurate and reliable so that every produced part was interchangeable with its similar part. Hence, the cost for reworking or material wastage could be minimized and the quality improved.