Spare Parts Inventory
SPARE PARTS INVENTORY MANAGEMENT WITH DELIVERY LEAD TIMES AND RATIONING
a thesis submitted to the department of industrial engineering and the institute of engineering and science of bilkent university in partial fulfillment of the requirements for the degree of master of science
By Ya¸ar Levent Ko¸a˘a s c g May, 2004
I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a thesis for the degree of Master of Science.
Assist. Prof. Dr. Alper Sen (Advisor) ¸
I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a thesis for the degree of Master of Science.
¨ u u Prof. Dr. Ulk¨ G¨ rler
I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a thesis for the degree of Master of Science.
Assist. Prof. Dr. Osman Alp
Approved for the Institute of Engineering and Science:
Prof. Dr. Mehmet B. Baray Director of the Institute ii
ABSTRACT SPARE PARTS INVENTORY MANAGEMENT WITH DELIVERY LEAD TIMES AND RATIONING
Ya¸ar Levent Ko¸a˘a s c g M.S. in Industrial Engineering Supervisor: Assist. Prof. Dr. Alper Sen ¸ May, 2004
We study the spare parts service system of a major semiconductor equipment manufacturer facing two kinds of orders of different criticality. The more critical down orders need to be supplied immediately, whereas the less critical maintenance orders allow a given demand lead time to be fulfilled. For this system, we propose a policy that rations the maintenance orders. Under a one-for-one replenishment policy with backordering and for Poisson demand arrivals for both classes, we first derive expressions for the service levels of both classes and then conduct a computational study to illustrate superior system performance compared to a system without rationing. We also conduct a case study with 64 representative parts and show that significant savings are possible
a thesis submitted to the department of industrial engineering and the institute of engineering and science of bilkent university in partial fulfillment of the requirements for the degree of master of science
By Ya¸ar Levent Ko¸a˘a s c g May, 2004
I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a thesis for the degree of Master of Science.
Assist. Prof. Dr. Alper Sen (Advisor) ¸
I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a thesis for the degree of Master of Science.
¨ u u Prof. Dr. Ulk¨ G¨ rler
I certify that I have read this thesis and that in my opinion it is fully adequate, in scope and in quality, as a thesis for the degree of Master of Science.
Assist. Prof. Dr. Osman Alp
Approved for the Institute of Engineering and Science:
Prof. Dr. Mehmet B. Baray Director of the Institute ii
ABSTRACT SPARE PARTS INVENTORY MANAGEMENT WITH DELIVERY LEAD TIMES AND RATIONING
Ya¸ar Levent Ko¸a˘a s c g M.S. in Industrial Engineering Supervisor: Assist. Prof. Dr. Alper Sen ¸ May, 2004
We study the spare parts service system of a major semiconductor equipment manufacturer facing two kinds of orders of different criticality. The more critical down orders need to be supplied immediately, whereas the less critical maintenance orders allow a given demand lead time to be fulfilled. For this system, we propose a policy that rations the maintenance orders. Under a one-for-one replenishment policy with backordering and for Poisson demand arrivals for both classes, we first derive expressions for the service levels of both classes and then conduct a computational study to illustrate superior system performance compared to a system without rationing. We also conduct a case study with 64 representative parts and show that significant savings are possible
Bibliography: [30] Y. Wang, M. A. Cohen, and Y. S. Zheng. Differentiating customer service on the basis of delivery lead times. IIE Transactions, 34:979–989, 2002.