We consider a smart manufacturing scenario where information regarding machine tool health and job statuses can be made available in real time. In the first part of the talk we analyze the evolution of the system to determine when to perform time-consuming tool-change maintenance by trading off increasing work-in-process against risks of tool failure and level of quality. The job arrival process, processing times, tool degradation process and tool replacement times are all stochastic. To analyze such an operations-aware maintenance scenario, we use a queuing model with a two-dimensional state and obtain associated performance metrics.
In the second part of the talk we consider a system where jobs with stochastic workloads arrive in an arbitrary fashion and upon arrival, their workload is revealed (enabled by smart infrastructure, for example). The tool on the machine gets used up deterministically based on the speed at which the jobs are processed. For such a system, we develop online algorithms that maximize the overall capacity by determining: (a) the speed at which each job is processed; and (b) the epoch when the tool is replaced. Our online approaches leverage the ability to reveal workload in real-time and effectively balance future uncertainties.
About the Speaker
Natarajan Gautam is a Professor and Associate Department Head for Undergraduate Affairs in the Department of Industrial and Systems Engineering at Texas A&M University with a courtesy appointment in the Department of Electrical and Computer Engineering. Prior to joining Texas A&M in 2005, he spent eight years at Penn State University in the Industrial and Manufacturing Engineering Department. His research focuses on optimal design, control and performance evaluation of stochastic systems with emphasis on computer-communication networks, energy conservation, and more recently smart manufacturing.
Prof Gautam is a Fellow of the Institute for Industrial and Systems Engineers (IISE). He is a department editor for IISE Transaction and, associate editor for the INFORMS Journal on Computing. He is the chief editor of IISE’s Industrial Engineering Body of Knowledge.