Planning Taking Account of the Sequence

Use

The following functions for structuring the sequence of operations during dispatching and rescheduling are available to you in the strategy profile:

  • Forming the dispatching sequence

  • Taking account of the operation sequence in the order

  • Operation date check

By combining the first two functions with further strategy settings, you can ensure the following under certain conditions

that operations are dispatched to a work center in the desired sequence

that the operations for an order retain the chronological sequence defined in the order during dispatching

Features

The functions of the strategy profile are described in detail below. The required settings for selected dispatching strategies are put together in the strategy profile in the section Actions .

Forming the dispatching sequence

This function arranges the operations in the desired sequence during dispatching or rescheduling of a group of selected operations. You define this sequence using the sort key which you specify for the dispatching sequence in the strategy profile. The system then performs dispatching or rescheduling for each individual operation in this sequence. Note: The dispatching sequence enables you to define only the sequence in which the system should "process" the dispatching/rescheduling of the operations. The planned operations for the work centers may subsequently occur in another sequence, depending on the planning situation and the strategies that you have defined.

For more information on the dispatching sequence, see Defining the Dispatching Sequence .

Taking account of the operation sequence in the order

This function is only relevant for orders without (explicitly maintained) relationships, that is, for

  • Planned orders

  • Production orders

  • Maintenance orders for which you do not specify any relationships

The function ensures that an operation can only be dispatched after its immediate dispatched predecessor (forward planning) or before its immediate dispatched successor (backward planning) in the order.

When dispatching or rescheduling an order, the system first determines the immediate dispatched predecessor (forward planning) or immediate dispatched successor (backward planning). Based on the dispatched predecessor (successor), the system performs a forward (backward) lead time scheduling. The system recalculates the dates of all operations that have not been dispatched as well as all operations without capacity requirements that either follow this predecessor (forward planning) or precede this successor (backward planning). It subsequently dispatches the predecessor to be dispatched or rescheduled after its immediate predecessor (forward planning) or before its immediate successor (backward planning). The immediate predecessor or successor can be a dispatched operation, an operation not yet dispatched or an operation without capacity requirements.

Note:

A dispatched operation is an operation that has capacity requirements and, through dispatching on the planning table, the status dispatched . Operations with capacity requirements are relevant operations for planning using the planning table. An order can also contain operations that do not have any capacity requirements. These are

Operations that, according to the control key, are not relevant for scheduling

Operations for which the system does not determine any capacity requirements based on the control key

  • Operations whose capacity requirements are 0 (standard values and formulas for calculating capacity requirements are not maintained in the operation or in the work center).

Operation date check

This function performs different checks for operation dates. Among other things, the system generates a warning in the planning log if you dispatch or reschedule an operation before a dispatched predecessor (forward planning) or after a dispatched successor in the order.

Actions

The settings for selected dispatching strategies that you must perform in the strategy profile before you manually or automatically dispatch a group of selected operations are put together in the following table. For order dispatching , you should ensure that you select all the operations for each order to be dispatched.

Strategy profile settings for different dispatching strategies

Dispatching strategy

Application area

Strategy profile settings

Generating a particular operation sequence for a work center

  • All order types

  • Use for the corresponding sort key or sequence and layout key for the dispatching sequence

  • Activate Forming the dispatching sequence

  • Deactivate Insert operation

  • Activate Dispatching at the earliest point in time

Order dispatching observing the operation sequence in the order

  • All order types

  • Orders for which all operations have capacity requirements

Use the corresponding sort key or sequence and layout key with the order and operation number as sort criteria for the dispatching sequence (ascending or descending order depending on the planning direction)

Further settings: See above.

 

  • Order types without relationships

  • Orders that also contain operations without capacity requirements (the first operation of an order must have capacity requirements).

Use the corresponding sort key or sequence and layout key with the order and operation number as sort criteria for the dispatching sequence (see above)

Activate Forming the dispatching sequence

Activate Follow operation sequence

Relationships

You define the sort key in the menu option Define sort key in the Customizing function Capacity leveling and extended evaluation .