Sequencing by Characteristics and Setup Reduction—Key Exercises

Basic Data Setup

Overview of Constraint Based Scheduling Data

Purpose: The purpose of this exercise is to create the required data used in the Constraint Based Scheduling (CBS) exercises. This sets up data for your site that needs to be done only once for all CBS exercises.

1. If you have not done so already, set up your site so that it includes all the CBS required data.

General exercise for Overview of Constraint Based Scheduling Data

Main Exercises

Using the Sequencing Wizard

Purpose: The purpose of this lesson is to demonstrate, using the Sequencing Assistant, how the sequence of operations for a work center can be determined based on characteristics.

Windows:
Simulation Client
Sequencing Assistant

Note: Before you begin this exercise, create the additional shop orders listed in the table below. In each shop order number, replace XX with your initials. Before creating the shop orders, make sure that the program is set to create shop orders with a status of Planned. This is specified on the Parameters for Distribution and Manufacturing window.

1. Reopen or refresh the Simulation Client.
2. Hold down the Shift key, and drag Work Center XX700 to the Gantt chart.
3. On the Tools menu, click Settings. The Settings dialog box appears.
4. In the Show area of the Settings/Plot Settings/Operations tab, verify that the Setup Times and Names check boxes are selected.
5. Open the Sequencing Wizard.
6. In the Start Date and End Date fields, enter the date range during which the sequencing should be performed. Use today's date (e.g., 2/06/01) for the start date and next Friday's date (e.g., 2/16/01) for the end date. The default range comes from the Sequencing Horizon (Days) field in the Scheduling Basic Data window.
7. In the Earliest Start Date field, enter tomorrow's date (e.g., 2/07/01).
8. In the Site field, enter your CBS site name.
9. In the Work Center field, enter XX700.
10. In the table below, insert a new row. Select the characteristic code 110 as the first sort criteria. Also select the Ascending sort order and Numeric sort type.
11. Click Next to proceed to the Operations To Sequence window. This window displays the orders and operations affected by the criteria.
12. Choose all the operations to sequence by selecting the Sequence? check box.
13. Click Next to proceed to the next window of the wizard. This window highlights the changes in the number of tardy orders before and after sequencing. The tardy orders after sequencing appear.
14. Click Next to proceed to the Sequencing Results window. This window displays the results of the new operation sequence for work center XX700. The lighter colors are scheduled first.
15. Click Finish to save the new schedule.
16. Open the Simulation Client. On the File menu, click Open Workspace. Select the file Sequence.fsw, and click Open.

Reducing Setups

Purpose: The purpose of this lesson is to use a work center setup matrix to define and schedule setup changeover times between operations with different characteristics.

Windows:
Work Center
Schedule Operations
Simulation Client
Sequencing Assistant

Note: The operations scheduled on the XX700 resource have an improved sequence, but the setup time of the operations does not reflect reality. To properly reflect the changeover times between the operations, you need to define a dependent setup matrix for Work Center XX700.

1. Open the Work Center window, and click the Setup Matrix tab.
2. Create a new record.
3. In the Characteristic Code field, enter 110.
4. In the Default Setup Time field, enter 0.25 (hours).
5. Save your changes. A dependent setup matrix for the three characteristic values of Characteristic Code 110 is automatically created.
6. Define the setup changeover times as follows:

7. Open the Schedule Operations dialog box to reschedule the CBS site.
8. In the Site field, enter your site.
9. In the Dispatch Rule list, click Sort by Earliest Due Date.
10. Open or refresh the Simulation Client to view the new schedule. Plot Work Center XX700 and its resource on the Gantt chart. Note that the setup times between each operation reflect the changeover times defined in the setup matrix of the work center. Once again, the sequence of the operations is not desirable.
11. Open the Scheduling Basic Data window.
12. Under Setup Optimization, click Use Part Number. This indicates that CBS should not schedule a setup when consecutive operations of the same part or part/operation occur on a work center resource.
13. Open the Sequencing Assistant.
14. In the Start Date and End Date fields, enter the date range during which the sequencing should be performed. Use today's date (e.g., 2/06/01) for the start date and next Friday's date (e.g., 2/16/01) for the end date.
15. In the Earliest Start Date field, enter tomorrow's date (e.g., 2/07/01).
16. In the Site field, enter your CBS site name.
17. In the Work Center field, enter XX700.
18. Insert a new row in the table below. Select Characteristic Code 110 as the first sort criteria. Also select Ascending as the sort order and Numeric as the sort type.
19. Click Next to proceed to the second window of the wizard.
20. Choose all the operations to sequence by selecting the Sequence? check box.
21. Click Next to proceed to the third window of the wizard. Click Next again to proceed to the fourth window.
22. Select Release on all the shop order operations.
23. Click Finish to save the new schedule.
24. Open the Simulation Client. Verify that the operations are scheduled in the correct order for Work Center XX700. The amount of setup time has also been reduced.