1 / 23

The Simulation Project

Learn the basics of modeling manufacturing systems, from problem definition to analysis of results, with a focus on material handling systems. Discover key principles, goals, issues, and performance measures in manufacturing modeling projects.

jhildebrand
Download Presentation

The Simulation Project

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The Simulation Project

  2. Simulation Project Steps a.- Problem Definition b.- Statement of Objectives c.- Model Formulation and Planning d.- Model Development and Data Collection e.- Verification f.- Validation g.-Experimentation h.- Analysis of Results i.- Reporting and Implementation

  3. Basic Principles of Modeling • To conceptualize a model use • System knowledge • Engineering judgement • Model-building tools • Remodel as needed • Regard modeling as an evolutionary process

  4. Manufacturing Systems Simulation

  5. Manufacturing Systems • Material Flow Systems • Assembly lines and Transfer lines • Flow shops and Job shops • Flexible Manufacturing Systems and Group Technology • Supporting Components • Setup and sequencing • Handling systems • Warehousing

  6. Production Control Supplies Storage Packing and Shipping Characteristics ofManufacturing Systems • Physical layout • Labor • Equipment • Maintenance • Work centers • Product • Production Schedules

  7. Modeling Material Handling Systems • Up to 85% of the time of an item on the manufacturing floor is spent in material handling. • Subsystems • Conveyors • Transporters • Storage Systems

  8. Goals and Performance Measures • Some relevant questions • How a new/modified system will work? • Will throughput be met? • What is the response time? • How resilient is the system? • How is congestion resolved? • What staffing is required? • What is the system capacity?

  9. Goals of Manufacturing Modeling • Manufacturing Systems • Identify problem areas • Quantify system performance • Supporting Systems • Effects of changes in order profiles • Truck/trailer queueing • Effectiveness of materials handling • Recovery from surges

  10. Performance Measuresin Manufacturing Modeling • Throughput under average and peak loads • Utilization of resources, labor and machines • Bottlenecks • Queueing • WIP storage needs • Staffing requirements • Effectiveness of scheduling and control

  11. Some Key Modeling Issues • Alternatives for Modeling Downtimes and Failures • Ignore them • Do not model directly but adjust processing time accordingly • Use constant values for failure and repair times • Use statistical distributions

  12. Key Modeling Issues -contd • Time to failure • By wall clock time • By busy time • By number of cycles • By number of widgets • Time to repair • As a pure time delay • As wait time for a resource

  13. Key Modeling Issues -contd • What to do with an item in the machine when machine downtime occurs? • Scrap • Rework • Resume processing after downtime • Complete processing before downtime

  14. Example • Single server resource with processing time exponential (mean = 7.5 minutes) • Interarrival time also exponential (mean = 10 minutes) • Time to failure, exponential (mean=100 min) • Repair time, exponential (mean 50 min)

  15. Example 5.1 -contd • Queue lengths for various cases • Breakdowns ignored • Service time increased to 8 min • Everything random • Random processing, deterministic breakdowns • Everything deterministic • Deterministic processing, random breakdowns

  16. Trace Driven Models • Models driven by actual historical data • Examples • Actual orders for a sample of days • Actual product mix, quantities and sequencing • Actual time to failure and downtimes • Actual truck arrival times

  17. A sampler of manufacturing models from WSC’98 • Automotive • Final assembly conveyor systems • Mercedes-Benz AAV Production Facility • Machine controls for frame turnover system

  18. A sampler of manufacturing models from WSC’98 -contd • Assembly • Operational capacity planning: daily labor assignment in a customer-driven line at Ericsson • Optimal design of a final engine drop assembly station • Worker simulation

  19. A sampler of manufacturing models from WSC’98 -contd • Scheduling • Batch loading and scheduling in heat treat furnace operations • Schedule evaluation in coffee manufacture • Manufacturing cell design

  20. A sampler of manufacturing models from WSC’98 -contd • Semiconductor Manufacturing • Generic models of automated material handling systems at PRI Automation • Cycle time reduction schemes at Siemens • Bottleneck analysis and theory of constraints at Advanced Micro Devices • Work in process evolution after a breakdown • Targeted cycle time reduction and capital planning process at Seagate

  21. A sampler of manufacturing models from WSC’98 -contd • Semiconductor Manufacturing - contd • Local modeling of trouble spots in a Siemens production facility • Validation and verification in a photolithography process model at Cirent • Environmental issues in filament winding composite manufacture • Order sequencing

  22. A sampler of manufacturing models from WSC’98 -contd • Materials Handling • Controlled conveyor network with merging configuration at Seagate • Warehouse design at Intel • Transfer from warehouse to packing with Rapistan control system • Optimization of maintenance policies

  23. SimSource Deneb Valisys (Tecnomatix) Open Virtual Factory EON Simul8 Manufacturing Simulators • ProModel • Witness • Taylor II • AutoMod • Arena • ModSim and Simprocess

More Related