We propose a new type of repairman model in which failures may require multiple repair operations, each done by a specialized repair crew. These repair operations may occur simultaneously. An analysis of the model is carried out using diffusion approximation techniques. The analysis predicts...

Most manufacturing systems are large and complex and operate in an uncertain environment. One approach to managing such systems is that of hierarchical decomposition. This paper reviews the research devoted to proving that a hierarchy based on the frequencies of occurrence of different types of...