Queueing network model for a single-operator machine interference problem with external operations

Machine interference is a significant problem in many manufacturing systems. Prior research shows that machine interference may be as high as 10% of machine time. This paper proposes a queueing network model for a singleoperator, machine interference problem with external operations, i.e., those tasks that can be completed while the machine is running. The interactions for part/machine and machine/operator are modeled as an open and a closed queueing network, respectively. In the open network, part inter-arrival time follows an exponential distribution. In both networks, service times follow a general distribution that is characterized by their first two moments. An iterative procedure is developed to solve the proposed model. Solution quality is justified by an industry-based case study. Data were collected from the integrated circuit (IC) ink-marking machines of a leading IC packaging company in Taiwan that allowed the construction of an experimental design for computational tests that encompassed a wide range of production scenarios. Empirical results show promise for the proposed methodology in helping to solve industrial problems. Model limitations as well as future research opportunities are discussed. 2004 Elsevier B.V. All rights reserved.