DUAL-RESOURCE CONSTRAINED SERIES SERVICE SYSTEMS

A Poisson arrival, exponential service queueing system consisting of two service stages in series is the subject of this study. The distinguishing characteristic is that the system has only one laborer. The labor and machine limited system is compared to its ordinary machine limited counterpart by means of a comparison of simulation results and theoretical results. Two illustrative cost models are developed to explore implications of the experiments with respect to various facets of system design and control, including labor assignment procedures, size of labor force, and control of arrival and (or) service rates. Average labor utilization is proposed as a measure of system utilization for labor and machine limited queueing systems. From this emanates the concept of 'blocking' of labor and concomitant problems which complicate any non-experimental determination of average labor utilization in terms of system parameters. The possibility of equivalence relationships between labor and machine limited queueing models and reduced machine limited queueing models is also explored. Although the experimental systems yield one example of such a relationship, they also provide evidence to support a conjecture that no general equivalence exists.