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Purpose

The heijunka process is employed for production smoothing (leveling) purposes and is used in Lean Manufacturing to achieve an even distribution of the production volume and maximum mixing of the materials to be produced.

The heijunka process involves a number of different components:

  • Sales and Operations Planning (mySAP ERP)

  • Demand Management (mySAP ERP, mySAP SCM)

  • MRP (mySAP ERP, mySAP SCM)

  • Tabular Planning Board (mySAP ERP, mySAP SCM)

  • Capacity Planning (mySAP ERP, mySAP SCM)

  • Sequencing (mySAP ERP, mySAP SCM)

Prerequisites

Settings in Customizing

You make the settings for the heijunka process in the planning profile and the procedure profile in Customizing for Sequencing.

You can enter production smoothing (heijunka) as the procedure for sequencing in the procedure profile (see Settings for the Planning Profile ).

Recommended Settings for Material Requirements Planning

The following settings offer you a possibility of integrating a heijunka process in such a way that the individual functions are well harmonized.

  • You have set the Repetitive Manufacturing indicator in the MRP data in the material master record and specified at least one production version for the production line.

  • You have created rate routings for the production lines in line design in order to be able to roughly determine capacity requirements.

  • You have assigned one production version to the rate routing.

  • You have made the following settings for the scheduling of the planned orders in Customizing:

    • Sequencing is activated.

    • The scheduling level Via Sequencing has been specified for scheduling adjustment.

  • Furthermore, you should make the following settings for the lot size:

    • Choose a lot-sizing procedure that supports the generation of small, distributable lots (for example, a fixed lot size in the short-term area). If Kanban is used for production control, the lot size should orientate itself on the kanban quantity.

    • A periodic lot-sizing procedure for long-term planning that is not relevant to Kanban and sequencing.

Process Flow

In the following, production smoothing (leveling) in the area of repetitive manufacturing with in-house production is described. You are informed how sequencing can be used to replicate the heijunka process in repetitive manufacturing. Kanban control cycles are used to monitor production.

  1. The first step is to ensure via program planning that there is enough material and capacity in the long term to support the Lean Manufacturing process.

    The results from profitability analysis from CO-PA, the sales information system, and forecasting serve as the basis for this. This data is processed in sales and operations planning.

    In program planning (demand management), planned independent requirements are then created for finished products to ensure that demandcan be covered over a certain period.

  2. In the next step, the planned independent requirements are planned in MRP.

  3. The planning table of repetitive manufacturing gives you an overview of materials and production lines in terms of time and quantities.

    The planning table enables the planner to check the production quantities and the capacity utilization of the production line at a glance. If necessary, he or she can then reroute production quantities to alternative production lines.

    The planning table incorporates the sequencing functionality (see Planning Table and Sequencing ), which enables you to carry out short-term planning. You can use the planning table with rate-based scheduling for the long-term planning horizon.

  4. Sequencing

    The sequencing functionality is used for the sequence planning and takt-based scheduling of planned orders in repetitive manufacturing.

    The orders are scheduled according to the settings in the planning and procedure profiles (see Executing Sequencing ).

  5. Displaying the sequencing

    The central instrument for monitoring the planning in the heijunka process is the display mode of the sequence planning board. Here all scheduled planned orders are displayed in the specified sequence as well as all planned orders that have not yet been scheduled. This data is displayed for the relevant period of examination.

  6. Changes to existing planning situation

    If it is necessary to make changes to the existing planning situation, you can invoke sequencing in a special interactive planning mode. In the process, the system does not carry out an automatic re-planning but shows the current planning situation and capacity utilization in the period of examination. You can change the planning situation manually and manually schedule, reschedule, or deallocate planned orders. Furthermore, you can carry out new planning for a certain period (see Change Sequence Schedule Interactively ).

  7. Production with Kanban

    You use Kanban to control the actual production of materials. With Kanban, the production of the materials can be triggered and monitored, and production of the relevant quantities confirmed (see Kanban in the Heijunka Process ).

    The continuous production of a specified quantity of material ensures an even production volume without excessive fluctuations.

  8. Production monitoring on the Kanban Board

    You can use the kanban board to monitor the status of production. You see the status of the kanbans for a material that are in circulation, can reset the status, and display information on the planned orders for the kanbans.