Attribute Number Range Tables as Eligibility Constraints

Key Concepts

Operation attributes used in an Attribute Number Range Table can serve as additional eligibility constraints. This is particularly useful when similar resources can handle different ranges of materials. 

For example, you may have several similar machines that are able to cut steel pieces of different lengths. You may have a machine that is able to cut lengths from 1-15 inches and a different machine could be able to cut lengths from 10-20 inches. 

Setting an eligibility constraint on these machines will help the scheduler choose a machine that has the right capabilities. If there is a job that is set to cut a piece that is 8 inches long, it will only be able to schedule on the first resource. However, a job to cut a piece that is 12 inches long will be able to schedule on any of the two machines as the operation attribute is within the attribute number range set on both resources.

Attribute Number Range Tables as Eligibility Constraints

The following example will show how Attribute Number Range Tables can be used to constrain operation with Attribute Numbers on certain Resources. In the next section, we will cover how to create these tables and how to set the operation attributes on the job operation.

Scenario: You have two machines that can cut material pieces of different lengths. However, the length range for both machines is different.

You can create an Attribute Number Range Table for both CNC1 and CNC2 resources and check the Eligibility Constraint. This will ensure that only jobs that have an Attribute Number (set on the Job's Operation) that falls within the range set on the Resource can be scheduled on it. For example, an operation that required a length of 12 inches will not be able to schedule on a resource that can cut pieces of 1-10 inches as it falls outside of the eligible range.

 

CNC1 Resource Attribute Number Range Table:

The CNC1 Machine is configured in a way that will only allow Operations that have an Attribute Number between 0 and 15 for the Attribute Name "Length" to schedule on it. This means that Operations with lengths above this will not schedule on CNC1.

 

CNC2 Resource Attribute Number Range Table:

Similarly, CNC2 Machine is configured to allow Operations that have an Attribute Number between 10 and 20 for the Attribute Name "Length" to schedule on it.

In this scenario, operations that have Attribute Numbers between 10 and 15 will be able to schedule on either of the machines.

Note: The "Eligibility Constraint" must be checked to use Attribute Numbers as additional scheduling constraints.

These rules are in addition to other eligibility calculations such as resource capabilities, min/max resource limits, etc.

Multiple Attributes as Eligibility Constraints

The above scenario shows how setting a single Attribute Number Range as an Eligibility Constraint will prevent jobs with operation attribute numbers that fall outside of the set range from scheduling on the resource.

You can also set multiple Attributes Number Ranges, such as Length and Width, as Eligibility Constraints.

If an operation has multiple Attributes that are Eligibility Constraints, then they must ALL be valid for the Resource's Attribute Number Ranges to be considered Eligible.

Setting Up Attribute Number Ranges as Eligibility Constraints

  1. Create Attribute Number Range Tables
    1. Note: These tables can be imported or created manually in PlanetTogether by going to Settings | Scenario Data | Setup Tables.
    2. Table Type: Choose "AttributeNumberRange" as the type.
    3. Table Name: Create a name for the Table. Usually, we use the same name as the Resource that will be assigned the table.
    4. Attribute Name: Choose a name for the Attribute that will be used. For example: length, width, etc.
    5. Eligibility Constraint: This must be checked to use the attribute as an eligibility constraint on the resource.
    6. From Range Start/End: Specify the range of values that are accepted. Note: When creating an Attribute Number Range Table to use as a constraint, you do not need to set the "To Range Start/End" values.
  2. Assign the Table to the Appropriate Resource
    1. In the Setup Tables dialog, click the "Resource using this table" tab and select the Resource(s) that will use it.
  3. Set the Operation Attributes
    1. In the Job Dialog, go to the Operation | Attributes tab.
    2. Name: Set the name of the Attribute. This should match the "Attribute Name" of the Attribute Number Range Table.
    3. Number: The Attribute Number Range Tables will look at the "Number" field to determine if the operation can schedule on the Resource.

Attribute Number Range Tables to Incur Setup Time

The above scenarios looked as using Attribute Number Range Tables to constrain operations to eligible Resources. Using the "Eligibility Constraint" feature of these Tables will not affect the Setup Time that can be calculated using the same tables.

These tables can also be used to incur Setup Time when changing from one Operation Attribute Number to another. To process of using Attribute Number Range Tables to calculate Setup based on Operation Attribute Numbers is similar to what was outlined above, with a few additional details.

  1. Create Attribute Number Range Tables
    1. Note: These tables can be imported or created manually in PlanetTogether by going to Settings | Scenario Data | Setup Tables.
    2. Table Type: Choose "AttributeNumberRange" as the type.
    3. Table Name: Create a name for the Table. Usually, we use the same name as the Resource that will be assigned the table.
    4. Attribute Name: Choose a name for the Attribute that will be used. For example: length, width, etc.
    5. From Range Start/End and To Range Start/End:
      1. These values can be tricky to set. The Attribute Number Range Tables will calculate Setup when an Attribute Number changes from one value to another.
      2. The difference from using an Attribute Code Table is that you can specify a RANGE of values.
      3. In this case, to incur Setup when the Operation Attribute Number changes FROM a range of values TO a range of values.
      4. For example:
        1. From Range: Start (0) / End (3)
        2. To Range: Start (o) / End (8)
        3. In this case, whenever an Operation Attribute Number that is between 0 and 3 changes to a number between 0 and 8, you incur Setup. So going from 2 to 6 will incur Setup. So it going from 3 to 8. However, going from 5 to 2 will not incur Setup.
    6. Setup Minutes: Specifies the number of minutes that will be incurred when the Attribute Number changes from the FROM Range to the TO Range.
    7. Setup Cost: Specifies the cost of Setup.
  2. Assign the Table to the Appropriate Resource
    1. In the Setup Tables dialog, click the "Resource using this table" tab and select the Resource(s) that will use it.
  3. Set the Resource to Use Operation Attributes to Incur Setup
    1. On the Gantt, double-click the Resource to open the Resource Options dialog.
    2. In the Setup/Changeover tab, change the "Setup Included" field to "Use Operation Attributes".
  4. Set the Operation Attributes
    1. In the Job Dialog, go to the Operation | Attributes tab.
    2. Name: Set the name of the Attribute. This should match the "Attribute Name" of the Attribute Number Range Table.
    3. Number: The Attribute Number Range Tables will look at the "Number" field to determine if the operation can schedule on the Resource.
    4. IncurSetupWhen: This should be set to "Lookup by Attribute Number Range".