Scheduling for Cellular Manufacturing

Abstract

Alcatel-Lucent is a major player in the field of telecommunications. One of the products it offers to network operators is wireless infrastructure such as base stations. Such equipment is delivered in cabinets. These cabinets are packed with various pieces of electronics: filters, amplifiers, circuit packs, etc. The exact configuration of a cabinet is dependent upon the circumstances it is being placed in, and some 20 product groups can be distinguished. However, the variation in cabinets is large, even within one product group. For this reason, they are built to order.

In order to improve cost, yield and delivery performance, lean manufacturing concepts were applied to change the layout of the factory to one based on cells. These cells focus on improving manufacturing through standardised work, limited changeovers between product groups and better utilisation of test equipment. A key component in the implementation of these improvements is a system which schedules the cells to satisfy customer request dates in an efficient sequence.

This paper describes the transformation and the tool that was built to support the new method of operations. The implementation has achieved significant improvements in manufacturing interval, work in process inventory, first test yield, headcount, quality (i.e. fewer defects are found during the testing stage) and delivery performance. Although these benefits are mainly achieved because of the change to a cell layout, the scheduling tool is crucial in realising the full potential of it.