An analysis of the impact of plant and management variables in a multi-stage, mixed-model production system

‘Mixed model’ production lines are often used in manufacturing systems based on just-in-time techniques (i.e. kanban and sequenced kanban). In these production lines, different product types are manufactured simultaneously by processing very small batches, which can even be made up of a single piece. Also, when lines located upstream of the final assembly line (i.e. sub-assemblies, components, suppliers) are of ‘mixed-model’ kind, the major design and management problems to be solved are as follows: (i) defining the internal, logistic kanban parameters for the different lines (i.e. container capacity, buffer size, kanban upstream frequency, etc.); (ii) defining a short-term sequencing algorithm for the lines, which is often characterised by the need to keep the consumption of pieces manufactured upstream constant or to properly divide workloads over the available time span. This paper describes a logic model aimed at linking kanban parameters together. The validity of the logic model has been certified by the outcomes of a simulation model.