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 Capacity-Based Kanban Calculation in Case of In-House Production Locate this document in the navigation structure

Use

In the case of in-house production, you can have the available capacity of critical work centers taken into account in the automatic kanban calculation.

Integration

It is possible to take account of the capacity of critical work centers for all in-house-production strategies that use production orders as replenishment elements. The following control types are available:

  • Processing with planned orders and cost collectors

  • Processing using production orders

  • Processing with planned orders/preplanning with MRP

  • Processing with production orders/preplanning with MRP

Prerequisites

  • You have set the Take Capacity Situation into Account indicator in the Customizing activity Define In-House Production Strategies in Customizing for Kanban. You use this indicator to activate the function. The system then shows the Consideration of Capacity tab page in control cycle maintenance.

  • You have set the calculation type 1 (Calculation of Number of Kanbans) on the Kanban Calculation tab page in control cycle maintenance.

  • You have specified a planning work center on the Consideration of Capacity tab page in control cycle maintenance.

    The planning work center is the critical work center for which the system is to carry out a review of the capacity situation. The planning work center must be included in the routings for the materials that are to be planned.

  • If required, you have specified a trigger group on the Consideration of Capacity tab page in control center maintenance.

    A trigger group is a group of control cycles for materials of the same kind that are produced together at a planning work center and require the same setup state. It is advantageous to use trigger groups in the joint production of materials that are similar in nature. If you do so, the system does not allow for any setup times in the capacity-based kanban calculation in the event of a change in material within a trigger group.

Features

With the capacity-based kanban calculation, you can take the available capacity of bottleneck work centers into account in the case of in-house production. If you do not use this function, in the kanban calculation the system always assumes that infinite capacities are available at the work centers that are needed.

Calculation Process

In the kanban calculation, the system now performs the following additional steps:

  • The system calculates the capacity requirements for all control cycles that consume the available capacity of the same work center (planning work center).

  • The system checks whether the available capacity suffices to manufacture the planned production quantity.

  • The system calculates trigger points for the individual control cycles or for certain groups of control cycles with the aim of reducing the setup times.

Trigger Point

The trigger point indicates how many kanbans must be used up before replenishment is triggered. The status of the kanban containers whose contents have been used up is automatically set to Waiting . When the trigger point is reached, the system automatically sets the status of the waiting kanban containers to Empty . Use of the trigger point affords the following advantages:

Normally, the kanban containers are set to Empty individually, so that the replenishment signals are received individually in random order at the supply source. This leads to a large number of small lots and associated frequent resetups. You can now reduce setup times by specifying that the system is to first set the status of the individual containers whose contents you have consumed to Waiting . Only when the number of containers with the status Waiting reaches the trigger point does the system automatically reset the status to Empty , thus triggering replenishment.The supply source can then produce all the materials together. This leads to an improved capacity utilization.

the system calculates the same trigger point for all control cycles that belong to a trigger group.

Check Calculation Results

After the kanban calculation, you can check the results in the transaction Check Proposal (PK08N). To display the calculation results, choose the Calculation Details button. The following results are relevant to the capacity-based kanban calculation:

  • New trigger point of a control cycle

    The system has calculated the new value of the trigger point that the latter is to have in the control cycle in future.

    You can use the Adopt function to adopt the value from the last kanban calculation. However, you can also enter a new value for the trigger point manually here.

  • Number of kanbans due to capacity buffer

    In addition to the trigger point, the system has calculated the number of kanban containers that are needed as capacity buffers to provide sufficient material to bridge the period until replenishment is triggered. The system adjusts the capacity buffer whenever you perform the kanban calculation.

    The system calculates the capacity buffer according to the following formula:

    Capacity buffer of trigger group = trigger point – 1

    If you use a trigger group, each material of the group has the same trigger point. The number of kanban containers that constitute the capacity buffer is then distributed among the materials of the trigger group.

    Example Example

    A trigger group consists of the materials A1, A2, and A3. The requirements are distributed as follows: A1: 50%, A2: 25%, A3: 25%.

    The system has determined 5 kanban containers as the trigger point. The capacity buffer amounts to 4 containers, which the system apportions as follows:

    A1: 2 containers

    A2: 1 container

    A3: 1 container

    End of the example.
  • Capacity utilization (total)

    You can display the total capacity utilization of the planning work center that the system determined during the last kanban calculation.

    The total capacity utilization results from the utilization due to set-up and production.

  • Capacity utilization (setup)

    In addition, the capacity utilization of the planning work center due to setup is displayed.

  • Capacity utilization (production)

    In addition, the capacity utilization of the planning work center due to production is displayed.