A Model for Evaluating Manufacturing System Time Performances

Abstract

An effective planning activity requires precise forecasts, consistent time horizons and knowledge about the level of performance of the manufacturing system. Improving manufacturing flexibility is the best answer to the changes and the variability of market demand, because it increases the speed of response of the system to environmental influences. Characteristic performances, particularly throughput times and procurement and manufacturing lead-times, fix an upper limit in time fences, over which the Master Production Schedule must be frozen. Thus it urges the need/utility of developing an interpretative model of relations linking forecast aggregation levels (production and time aggregation) and characteristic lead-times in procurement and variation of production resources. The aggregation level measures the degree of detail in forecast information. In the two dimensions of time and product we have for growing aggregation levels, days, weeks, months, years as regards time and options, colours, versions, types, line of products for the product. Resources may be classified in relation to the aggregation levels their forecasts require. Furthermore this classification may be crossed with procurement lead-times related to each resource. This model shows the limits of the manufacturing system, showing logistic and material procurement time boundaries, in order to establish a well dimensioned frozen horizon. The model’s validity and reliability as a tool of analysis for manufacturing systems have been tested on the field. This paper describes the characteristics of the model and the results of its employment.