As according to the Magnuson-Moss Warranty Act, automobile manufacturers are required to provide spare parts for any model they sell, for a minimum span of 10 years. In the automobile/ aviation industry, the demand for replacement parts is generally met using conventional manufacturing processes such as injection molding (IM) and stocking parts in warehouses. IM proves economical when the demand is high and continuous. The demand for replacement parts is generally low and intermittent and stocking parts in inventory to meet future demands proves expensive and the possibility of stock-outs or parts going obsolete is high.

Rapid Manufacturing (RM) is an additive manufacturing technique that prints parts without the need of tools, unlike conventional manufacturing processes. Thus, it saves on the tooling cost, time to make the mold, and the need to stock various parts in order to meet the intermittent demand. There is a need for an alternative approach to meet low volume intermittent demands, and the Just in Time (JIT) production strategy incorporating RM serves as an option. In JIT, production starts when a demand is received from the customer. It also gives the Original Equipment Manufacturer (OEM) an option to make parts on the demand site, eliminating transportation and inventory holding costs.

The objective of this thesis is to develop a decision making framework to determine the economical supply chain strategy to meet the demand for replacement parts. The supply chain strategies considered are in-house manufacturing by the RM process called Selective Laser Sintering (SLS) in a JIT production environment, and stocking parts in centralized warehouses manufactured by IM to meet future demands. A mixed integer programming (MIP) model has been formulated to determine the unit cost of parts for the supply chain strategies under consideration. The results from the model are used to determine the significant part parameters affecting the cost of manufacturing by SLS using Regression Analysis. Based on the results, material volume and height of the part proved to be significant factors and a regression equation has been derived and validated for estimating the unit supply chain cost of parts manufactured by SLS.

Library of Congress Subject Headings

Just-in-time systems--Economic aspects; Automobile supplies industry--Management

Publication Date


Document Type


Student Type


Degree Name

Industrial and Systems Engineering (MS)

Department, Program, or Center

Industrial and Systems Engineering (KGCOE)


Scott Grasman

Advisor/Committee Member

Denis Cormier


Physical copy available from RIT's Wallace Library at HD9710.3 .M43 2015


RIT – Main Campus

Plan Codes