Repetitive Production Scheduling

A production schedule is built from multiple runs of schedule lines, based on the item order plan in Enterprise Planning. The original start date and end item of all the schedules lines from one run is the same. The runs are distributed over the available work cells based on the work cell's calendar in combination with the need by date of the schedule line.

Depending on the settings in the Repetitive Manufacturing Parameters (tirpt0100m000) session, scheduling can be fully automated, or manually adjusted.

Repetitive manufacturing uses schedule lines to plan manufacture of items. Planning and scheduling happens on several levels to manage all aspects of repetitive manufacture:

  • Material planning and lead time is required. In a repetitive manufacturing environment, material planning is a combination of an infinite planning and a finite scheduling. The main objective of the planning is material availability.

    The main objective of scheduling is an efficient production schedule. Material planning calculations are based on the item ordering data. Materials are supplied dependent on the consolidated material demand of the activated production schedule lines in a specific time period. Safety stock at the point of usage is considered when calculating demand, with the materials being supplied directly from the central warehouse to the work cell based on the run schedule.

    As reporting item completion happens as often as possible in repetitive manufacturing, you must define the triggers for the backflushing of material in the Repetitive Manufacturing Parameters (tirpt0100m000) session.

  • To optimize production efficiency and create a production run schedule. The scheduling horizon is defined in the item planning parameters as a number of days. For demand that is outside the scheduling horizon, infinite material planning is used. For demand that falls within the scheduling horizon, production scheduling is used based on the data in the related production model.

  • Sequencing is used the production to match the delivery sequence to minimizing the warehouse handling.

Production scheduling

After an item order plan is generated in Enterprise Planning a production schedule can be generated in the Repetitive Manufacturing planning engine.

Depending of the schedule horizon of the item order plan, two different types of supply are generated.

  • If the supply is within the schedule horizon new or changed run schedule lines are created.
  • If the supply is outside the schedule horizon and within the order horizon new or changed planned orders are created.

The list of materials, which is defined in the production model of the repetitive item that is planned, is used to generate the dependent demand for the materials.

Exception messages are used to report any errors that occur during generation of production run schedule. Error in the planning, rescheduling, and cancellation messages for Active run schedule lines are generated when conflict in planning must be resolved. In the Work Cell Planning (tirpt4102m210) session it is possible to manually adjust the generated production schedule: add and change new schedule lines, and adjust the status of existing lines. After rescheduling is completed, the production run schedule is rebuilt with the changes you specified from the input start date based on the availability of the related work cell.

After the schedule is complete, schedule lines must be released to trigger the start of production. This can be done either in the Release Production Schedule Lines (tirpt4202m100), Work Cell Group Planning (tirpt4602m200) or the Work Cell Planning (tirpt4102m210) sessions by selecting the relevant schedule lines and using the relevant command.

Once the schedule lines are released, production can begin.

Example

Item A is a manufactured item.

To produce item A, one item B is required.

Item B is a purchased item.

There are several independent demands for item A.

  • Planned production orders are generated in Enterprise Planning based on the item ordering date.

    In this example two planned production orders are generated because:

    • The demands are cumulated within the order interval.
    • The quantity is based on the order increment (1*1000)
    • The start date of the planned order is based on the lead time and the availability in the calendar linked to the required work cell.
    • If the start date of the planned order is within the schedule horizon, the planned order is replaced by a schedule based on the date in the item's production model.

    • For item A, there are four planned schedule lines with the following characteristics:

      • 250 pieces per line, this is the maximum line quantity defined in the production model.
      • The lines are scheduled forward from the stat date of the planned order.
      • The work cell responsible for production. Dependent on the availability and the existing work cell load, the schedule lines can be spread across several work cells.
    • There are six dependent demands for item B.
    • Planned purchase orders based on item B's ordering date are generated in Enterprise Planning.

    • To complete the order for item A, three planned purchase orders are generated

      • To cumulate demands within the order interval.
      • The quantity is based on the order increment (500).
      • The start date of the planned order is based on the lead time on the item purchase date.

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