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 Quantity Restriction

Definition

You can use this restriction category to limit the occurrence of a characteristic to either a minimum or a maximum quantity per day or shift.

Use

You use the quantity restriction to gear the production program to the quantity of a certain component. It may be, for example, that a supplier can only deliver 50 pc of component A per day.

In restriction processing, you use the Minimum and Maximum fields to specify the minimum and maximum quantities.

Note Note

The minimum quantity can only be taken into account by the genetic algorithm and the LP procedure . The LP procedure considers the minimum quantity as a soft restriction.

If you specify a larger minimum quantity than can be produced on the basis of the line capacity , the system will correct the minimum quantity when the optimization procedure is invoked and replace it with the maximum possible quantity that can be produced on the line.

End of the note.

You can define the minimum or maximum quantity, or both for a restriction. The system attempts to take the specified quantities into account as follows:

  • Maximum Only

    If you specify the maximum quantity in the Maximum field, the system can only take this quantity into account.

    Example Example

    For the characteristic value combination COLOR = ‘blue’ , specify the maximum quantity of 10 Pieces per Shift in the restriction.

    The system can then schedule up to ten blue vehicles for each shift on the line.

    End of the example.

  • Minimum Only

    If you specify the minimum quantity in the Minimum field, the system can only take this minimum quantity into account.

    Example Example

    For the characteristic value combination COLOR = ‘blue’ , specify the minimum quantity of 10 Pieces per Shift in the restriction.

    The system must then schedule at least ten blue vehicles for each shift on the line in order to adhere to the restriction.

    End of the example.

  • Minimum and Maximum

    If you specify quantities in both fields, the system will take both the minimum and maximum quantities into account. The minimum quantity that you specify must be smaller than or equal to the maximum quantity.

    Example Example

    For the characteristic value combination COLOR = ‘blue’, specify a minimum quantity of 3 pieces and a maximum quantity of 10 pieces per shift in the restriction.

    The system must then schedule at least 3 but a maximum of 10 blue vehicles on the line.

    End of the example.

  • No Quantity Specification

    If you do not specify a quantity in the Minimum and Maximum fields, the system will set each of the two quantities to 0. In this case, the system cannot schedule any orders with the characteristic value assignment you specified on the Dependencies tab page. You use this setting if you want to ensure that no orders with the specified characteristic value assignment are to be produced on certain days on certain lines.

Example

As your system supplier can only deliver a maximum of 300 sunroofs a day, you define a quantity restriction with the following object dependencies:

Sunroof = “Yes”

You define the following period of validity and weighting for the restriction in the start date view :

  • The restriction is valid from the 1 st June 2001 in the first shift and is initially valid indefinitely because no other validity period has been maintained.

  • In the Max. and Time Unit fields, you have specified that a maximum of 300 vehicles with the characteristic sunroof can be scheduled per day.

  • The row is defined as “hard” with the weighting 0 due to the fact that this restriction must not be violated because the restriction is due to the supplier’s limited capacity.