1、Candid Comparison of Operational Management Approaches,James R. Holt, Ph.D., PE, Jonah-Jonah Washington State University-Vancouver Engineering Management Program,Purpose for Presentation,Understand different approaches to managing repetitive production processes Highlighting several key production m
2、easurements Comparing performance on an equal playing field Highlight consistent key variables Draw some conclusions of value,The Situation,Describe many different production management approaches into generally acceptable methods Create a generic simulation model and test procedure that is fair to
3、all management approaches Provide sensitivity analysis to make fair comparisons,Fairness Paramount,Production process straight forward No disassembly, no assembly, Parallel machines accept any work No set-ups No people or logistics problems No priority work Independent - No artificial slow downs Ava
4、ilable material available immediately Tolerant customer that buys all immediately,The Challenge,Production Model 10 machines of 6 types - mostly in parallel Production times mostly balanced Double Constraint Free flow of products on any path Normal distribution on production 90% productive capacity
5、Repetitive scheduled arrivals,Production Simulation Model,Arrival Schedule,Management Approaches,Traditional push manufacturing Push with batch size of 10 Work cells Just-In-Time with kanban of 1 Just-In-Time with kanban of 3 Lean manufacturing Drum-buffer-rope Agile manufacturing,Measurements Based
6、 on 20 Trials of 100 hrs,Average work-in-process (alpha=0.02) Average flow time (in process only) Average efficiency of all machines Average produced in 100 hours Profit based on $80 per part and $30,000 operating expense per 100 hours ROI based on annualized investment ($50,000 per 100 hours) plus
7、inventory,Definition: Traditional,Efficiency is very important at every work station Push materials in as soon as possible No limit on Work-In-Process (queues) Work flows first-in-first-out No priorities Transfer batch size of one,View: Trad.sim,Definition: Traditional Batch,Optimizes the costs of e
8、fficiency and investment Lot sizes planned to optimize individual performance Lot sizes reduce set-up times Efficiencies of scale Parts moved between machines in lots of 10,Definition: Cell Production,Dedicate machines to products Special treatment of products Some efficiencies possible within cells
9、 Easier to manage / control / improve processes in cells Cell draws from, connects to rest of plant,View: Cell.sim,Definition: Just-In-Time,Pull system - produces to demand Work-In-Process controlled (limited) Kanban card governs flow between machines (parts move only on demand) Simulation JIT1: Kan
10、ban card of 1 Simulation JIT3: Kanban card of 3 Demand is at max level of performance,View: JIT1.sim,Definition: Lean Manufacturing,Maintain low work-in-process Maintain high efficiencies (trim excess capacity) Use push or pull approach This simulation uses a balanced line with maximum work-in-proce
11、ss of 5 parts per machine,View: Lean.sim,Definition: Drum-Buffer-Rope,Drum process is slowest machine(s) Buffer protects capacity of drum - holds adequate work-in-process to keep drum at maximum efficiency Rope restricts excess work from entering system - limits maximum work-in-process in front of t
12、he constraint Buffer size limited to 17 parts,View: Dbr.sim,Definition: Agile Production,Very flexible manufacturing Respond to demand, workload shifts as needed Multi-skill machines / workers to perform a variety of tasks Machines added / workers added / moved to meet high demands In this simulation, workers move if own queue is 2,View: Agile.sim,Performance Measures,Performance Measures,Performance Measures,Summary Measures,Join WSUs Engineering Management Program,EM 526 Constraints Management EM 530 Applications in Constraints Managementhttp:/www.cea.wsu.edu/engmgt/,
