Fall 1999

ME/IE 8773-8774

LOT SIZING MODELS TO MINIMIZE CYCLE TIME

by

Mark L. Spearman
University Chair in Manufacturing Management
Culverhouse College of Commerce
and Business Administration
The University of Alabama
Tuscaloosa, Alabama 35487-0226

Wednesday, December 15, 1999
1:25 - 2:15 p.m.
Room 108 ME
Broadcast on UNITE Channel A
Coffee will be available in 152 ME following the seminar

We consider a different criteria for lot sizing, that of cycle time (sojourn time) and contrast this with the usual setup cost and carrying cost. We obtain the counter-intuitive result that parts with longer setup times should have smaller batch sizes. We also provide an easy approximation for the optimal solution. Finally, we discuss the problem of setting reorder points in a make-to-stock system with significant setup times.

Mark L. Spearman holds the University Chair in Manufacturing Management in the Culverhouse College of Commerce and Business Administration at the University of Alabama. His research and teaching involve the development of new production and inventory control strategies. He is co-author, with Wallace J. Hopp, of the book, "Factory Physics: The Foundations of Manufacturing Management" that was named the IIE Book of the Year (1998). He has worked with more than 25 companies applying the principles of factory physics to improve operations by increasing throughput and reducing cycle times and inventories.

Prior to joining the Culverhouse College, Spearman worked for 4 years in the School of Industrial and Systems Engineering at Georgia Tech and for 9 years in the Department of Industrial Engineering and Management Sciences at Northwestern University. Before he obtained his Ph.D., he worked over 5 years as an engineer for Monsanto Corporation, Superior Oil Company, and IBM Corporation.

He is Past-President of the Manufacturing and Services Operations Management Society and has served as Secretary and a Member of the Board of the Production and Operations Management Society. He is an Area Editor of "Production and Operations Management," a Senior Editor for "Manufacturing and Service Operations Management," and an Associate Editor for "Management Science." He holds a Ph.D. in Industrial Engineering, is a Senior Member of IIE, a full member of INFORMS, and is Certified in Production and Inventory Management by APICS.