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Systems for Planning and Control in Manufacturing
Figure 20.16 JIT approach
The
The JIT approach is fundamentally different. Here, the root causes of the problems are attacked using a variety of techniques (e.g. TQM, TPM and SMED). Then, stock levels are reduced and this reveals other problems which themselves are attacked as depicted in Figure 20.16. This process is repeated indefinitely, leading to continuous improvement (or kaizan).
20.7 JIT and purchasing 20.7.1 Traditional purchasing strategies Traditionally, purchasing has been regarded as separate from the overall manufacturing system. Production planning control would generate requisitions and these would be converted by purchasing into orders. One reason for this was that labour was normally the most significant factor influencing cost. Typically, the majority of purchasing effort was spent on expediting overdue orders. This is often due to an absence of overall planning systems to realistically determine purchase requirements. Purchasing normally focused on price and the relationship with suppliers was adversarial. Large numbers of suppliers were perceived as a good thing. This allowed purchasing to apply pressure during price negotiations.
20.7.2 Influence of JIT Ideally, purchasing will be part of the manufacturing management system. Indeed, the suppliers will also be considered an integral element in the manufacturing system. This is particularly important in manufacturing today where material makes up a significant part of overall product cost. The influence of Japanese manufacturers has led to a more cooperative relationship between customer and supplier. Increasingly,