On Capacity Measurement in Two Classes of Shop Floor Problems with Multifunctional Parallel Machines

Abstract

Capacity measurement is of crucial importance in business and manufacturing and is intimately related to both finite and infinite capacity planning. There is a vast literature on this subject and capacity may be defined in various ways. This paper investigates, within two small scale examples, some issues regarding capacity measurement in a shop floor with multifunctional parallel machines that have to process a specified quantity of products of different types, and with specific operations requirements, in a specified working time. In the first example, each operation type has a specific operation unit time, independently on the working machine, while in the second example each machine can execute any operation from its capabilities portfolio in a unique operation’s unit time, with a unique associated operation unit cost. The study emphasizes, in the first example, that the capacity measurement depends not only on machines capabilities, on products requirements and on the imposed working time, but also on the allocation strategy of groups of machines to groups of products, while the second example shows that, in case of machines with unique operation unit time for all operation types, the maximal number of operations executable in given working time is a valid capacity measure. The discussed examples may serve as starting point for defining capacity planning procedures for more complex scenarios that can be tested using dedicated software tools, targeting industrial applications.