Macro or Micro Simulation Models

[Shashank Verma]

Could someone tell me how to classify simulation models as macro or micro models? What factors need to be considered?

[ewilliams]

A macro model is conceptually larger (a production department or process, or even a whole manufacturing operation). A micro model is conceptually smaller (e.g., the detailed logic of one machine, can the robot undertake its entire cycle of duties without collision). There is no exact dividing line. Typically, macro models are built using discrete-event simulation software (e.g., ED, SIMUL8, WITNESS), whereas micro models may be built with robotic simulation (e.g., IGRIP) or ladder-logic simulation.

[Wolverine]

Here is my take on that:

Factors to be considered:
• Span of model
- Factory level planning and control operations.
- Individual manufacturing cell model.
• Accuracy requirements
- Accurate throughput estimate is required.
- Compare two systems - which one gives more
output.
• Variables and policies of interest in the study
Macromodel
-- Inventory control policies
-- Scheduling policies
-- Buffer inventories
-- Part batch sizes
-- Model changeover strategies
Micromodel
-- Number of machines
-- Labor requirements
-- Layout of manufacturing cells
-- Material handling equipment requirements

Hope this helps.

[Shashank Verma]

What are the macro models used for ?

[rlote]

Macro models are primarily used to make a "rough cut" analysis to:
… Verify line throughput rates.
… Identify bottleneck components.
… Evaluate inventory levels between departments or lines.
What are the objectives of your simulation study?