This page contains a tutorial demonstrating how to build a production system model for an engineering process. This tutorial assumes that the reader has read through the Map a Production System and Model a Production System sections of the Help Menu. If not, please refer to those sections of the Help Menu before continuing.
Engineering Company
An engineering firm has a team tasked to creating 220 isometric piping and line drawings for a project within a 10 week time window. The team is unsure if they have enough capacity to meet the demand set by the project schedule. Use the following information to develop a model of the engineering production process and provide the team with an answer to their question.
Next, open the production process and draw a single production routing with the following characteristics. Add all relevant data depicted below. All input fields not mentioned in this section’s tables should be kept as their default values.
| Process Center Name | Work Schedule | Batching Type | Number Available |
|---|---|---|---|
| Designers | 1x5x8 | Sequential | 8 |
| Engineers | 1x5x8 | Sequential | 7 |
| Shape | Shape Name | Sequence | Process Center | Average Nominal Process Rate per Machine (Units/Hour) | SCV of Process Times for a Transfer Batch |
|---|---|---|---|---|---|
| Stock | 3D Model | ||||
| Operation | Prepare ISO | 100 | Designers | 1 | 1 |
| Operation | Check ISO | 200 | Designers | 12.0482 | 1 |
| Stock | ISOs Ready for Stress Testing | ||||
| Operation | Send lines to Stress Test | 100 | Designers | 4 | 1 |
| Operation | Perform Stress Analysis to lines | 200 | Engineers | 0.0694 | 1 |
| Operation | Update drawings per Stress Analysis | 300 | Designers | 0.333 | 1 |
| Operation | 400 | Designers | 0.222 | 1 | |
| Operation | Scrub line ISOs | 500 | Designers | 0.667 | 1 |
| Operation | Check Quality | 600 | Designers | 0.667 | 1 |
| Stock | Lines Ready for Transmittal |
Work Groups
Work groups will not be used in this model. Therefore, leave the default values as is. Refer to Work Groups for a complete description of work groups and their data elements.
Units
Next, open the Unit of Measure menu and create two units of measure named “ISO” and “Lines” for the units that will flow through this engineering production system. The Default Unit of Measure can be renamed, or the user can create a new one. A unit of measure is required to account for various WIP types that flow throughout a production system. Refer to Unit of Measure for a complete description of UOMs and their data elements.
Product Flows
Next, open the Product Flows menu. By default, every new model will come with a product flow named “Default Product Flow”. Any routing generated will automatically be assigned to this product flow. Create two product flows containing the following information. Refer to Product Flows for a complete description of Product Flows and their data elements.
| Description | UOM | AICCR (%) | CONWIP |
|---|---|---|---|
| ISO with Stress Test | ISO | 20 | 25 |
| Lines with Stress Test | Lines | 20 | 25 |
| Description | Max WIP | Max Throughput | Max Cycle Time |
|---|---|---|---|
| ISO with Stress Test | 20 | 6 | 2 |
| Lines with Stress Test | 200 | 3 | 100 |
Routings
Next, open Routings. There will be two routings generated. Change the names of the routings to “ISO with Stress Test” and “Lines with Stress Test”. Refer to Routings for a complete description of Routings and their data elements.
Items
Recall that the Engineering Company needs to produce 220 lines in the next 10 weeks. This creates an average demand of 22 lines per week. Furthermore, for each Line with Stress Test, the team needs to produce 3 ISO with Stress Test. Be sure to generate a Bill of Materials for this relationship.
Now, open the Items list. Open the “Default Item” and rename its Description and ID to “Lines with Stress Test”. Then create another item for “ISO with Stress Test”. Next, update the following values in each item table. Refer to Items and Bill of Materials for a complete description of Items and their data elements.
| Parameter | Value |
|---|---|
| Description | ISO with Stress Test |
| ID | ISO with Stress Test |
| Unit of Measure | ISO |
| Average Number of Orders (Per Period) | 0 |
| Variance of Orders (Per Period) | 0 |
| Parameter | Value |
|---|---|
| Description | Lines with Stress Test |
| ID | Lines with Stress Test |
| Unit of Measure | Lines |
| Transfer Batch (Units) | 7 |
| Average Number of Orders (Per Period) | 22 |
| Variance of Orders (Per Period) | 10 |
| Current Reorder Quantity | 7 |
Item Routings
Next, open the Item Routings list. Item routings tell the model which routing to send each item. Create a new Item Routing and name it “ISO with Stress Test”. Create another Item Routing named “Lines with Stress Test”. Set the appropriate items and routings. For this model, keep Fraction of Releases at its default value, 100%. Refer to Item Routings for a complete description of Item Routings and their data elements.
Current Production System Analysis
The model is now complete and ready to be analyzed. Select the Production System Analysis button to run the model. The production system analysis will reveal that the current system does not have enough capacity to meet the needed demand.
If the reader hasn’t already, read through the previous sections of the Help Menu (listed below). These sections will guide the reader on how to interpret, analyze and optimize this engineering production system using an assembly production process as an example.
- Model an Assembly Flow
- Interpret Flow Model Results
- Optimize an Assembly Flow
- Verify and Validate a Flow Model
Once finished with these sections, return to this model and decide how the capacity of the production system will be increased. Try to get the capacity utilizations for all resources below 90%. Then, for an additional challenge, determine how to reduce the cycle time of the Lines with Stress Test by at least 50% without further increasing resources, reducing demand, or changing process times.