Effective modeling of throughput time in semiconductor assembly processes

We develop discrete event simulation (DES) models of a semiconductor assembly process capable of predicting average throughput time (TPT) within 6% of factory-floor measured average TPT. This represents a significant improvement over current DES models in the semiconductor industry, which commonly yield average TPTs that are 25% to 50% less than those measured on the factory floor. We accomplish this improvement by (1) constructing a separate area model of the system's constraint, (2) inputting an exact lot-starts schedule to the model, and (3) using failure parameters which are operation dependent rather than time dependent. In addition, we devise heuristics to parallelize the simulation process and significantly reduce computational expense in DES models, thereby affording the inclusion of detailed factors. We perform various sensitivity studies on the assembly's constraining process which indicate that operators and shift effects do not have a significant effect on average TPT. We also apply the series-parallel flow-line analytical model developed by Gershwin [8] and Burman [2], obtaining average TPTs which are 27% of factory-floor measured average TPT with numerical computational times of under a second.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

1998

Author dc:creator

• Cervantes José A. (José Armando), 1973-

Advisor dc:contributor.advisor

• Kevin Otto and Stanley B. Gershwin.

• Mechanical Engineering
• Sloan School of Management

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/50485

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/50485