Analysis of a service center in a multiline factory

It has been demonstrated that several performance measures (e.g., expected delay and number in the system) improve when n servers take customers from a single queue rather than from n separate queues dedicated to individual servers. In this paper, we discuss the application of this concept in a manufacturing environment. In a multiple factory, common machines from individual lines were pooled to form a service center. The expected benefits, however, were not realized and we were called in to identify the cause of the poor performance. To analyze the service center, a Σ Gl/G/1 queueing model (the superposition of independent renewal arrival streams offered to a general single server) was used. We found that the material handling scheme in place significantly degraded the system performance. Using the model, alternative schemes were proposed to improve the performance of the facility.