Review Models and Analysis of Manufacturing Systems 82404

Review Models and Analysis of Manufacturing Systems 8/24/04

Purpose of the course: n n n Provide an understanding of problems and issues in manufacturing design Build flow models embodying the components of the manufacturing process Identify waste in the manufacturing process Use models to quantify waste Use operations research tools to analyze models and make decisions 2

The production system may be very complex 3

The process model 4

Multiple products 5

Flow Analysis n n n Grouping and waste And, OR, Proportion Nodes Cycles with and without waste Flow ratio Unit time Complex Networks 6

Defects and Inspection 7

Work in Process n WIP = Flow rate*residence time Computing WIP Evaluating WIP 8

Inventories 9

Production in Lots n Production and transfer lots Effects on machine capacity n Effects on WIP n n n Processing: Depends on the production and transfer lot Queuing delays: Depends on lot size 10

Variability n Poisson and Nonpoisson Systems 11

Queuing Networks Depends on machine assignment Depends on product demands Depends on operation times Depends on flow ratios 12

Material Movement n n n Types of layouts Criterion for comparison The Craft method 13

Kinds of Problems n Fixed machine assignments and capacities n n Fixed machine assignments and product mix n n Find the bottleneck Find the product mix Compute queuing delays, WIP, throughput time Select capacities (number of machines) Compute queuing delays, WIP, throughput time 14