1. Lab Module 02 Serial Manufacturing Line
Copyright © Jeffrey S. Smith and Simio LLC | All Rights Reserved

2. Objectives and Outline
Lab Objectives
Continue learning basic Simio modeling
Understand the basics of symbols and the default object instance symbol list
Lean about experiment responses
Learn how to use SMORE plots
Lab Outline
Video 1 - Describe the 3-stage manufacturing system to be modeled, build the basic model, and verify the model
Video 2 – Add symbols to the model and learn how to change entity and server symbols as the model runs
Video 3 – Add experiment responses and view/interpret the Response Results (SMORE plots)
Video 4 - Assignment
Copyright © Jeffrey S. Smith and Simio LLC | All Rights Reserved

3. Serial Manufacturing Line
Machine
Grind
Package
Parts arrive at the rate of 60/hour.
Machining requires approximately 45 seconds/part.
10% of machined parts require re-machining
Grinding requires approximately 55 seconds/part.
10% of ground parts are deemed “bad” and are disposed of.
Packaging requires approximately 63 seconds/part.
Copyright © Jeffrey S. Smith and Simio LLC | All Rights Reserved

4. Build the Model!
Copyright © Jeffrey S. Smith and Simio LLC | All Rights Reserved

5. Video 03 – Experiment Responses and Response Results
A response is a Simio expression that is evaluated at the end of a replication. Responses can have:
Units (e.g., Time)
Objective (minimize or maximize)
Lower and Upper bounds
For our model, we’ll develop responses for:
Server utilization (Machine, Grind, Package)
Average time in system (for the population of Parts entities)
Average number in system (for the population of Parts entities)
Copyright © Jeffrey S. Smith and Simio LLC | All Rights Reserved

6. SMORE Plots
Nelson, B.L., “The MORE Plot: Displaying Measures of Risk and Error from Simulation Output,” Proceedings of the 2008 Winter Simulation Conference
Confidence intervals are measures of error and can be reduced by adding more replications.
Percentiles are measure of risk and can only be improved by changing the system.
Chapter 7 - Interpreting Simulation Results

7. Video 04 - Assignment Add Inspection and Rework steps after Grinding
After the grinding process, all parts go through an inspection step. There is a single inspector and the inspection takes between 30 and 50 seconds (uniformly distributed). 20% of the inspected parts are found to need rework (the remaining 80% go to packaging). There are two rework operators and rework takes between 5 and 10 minutes (uniformly distributed). 50% of the parts are still bad after rework and are scraped. The remaining 50% are sent to packaging.
Modify the model based on the system changes. Create responses for the following:
Server utilizations (Machine, Grind, Inspect, Rework, Packaging)
Time in system for the entire part population
Time in system for good parts
Time in system for scrapped parts
Number of parts in the system
Number of parts in the Input Buffer for the Packaging station (hint – you will need to use the expression editor to “explore” the Package server object components to determine the appropriate expression)
Copyright © Jeffrey S. Smith and Simio LLC | All Rights Reserved