Outlining Repetitive Manufacturing

Repetitive manufacturing is mainly used for production scenarios with high product stability, high repetition rates, and low product complexity.

In our business example, repetitive manufacturing is used to initiate and control the production of the wheels in our bicycle company. Repetitive manufacturing includes the following information:

• Which types of wheels are to be produced?
• How many wheels are to be produced in what periods of time?
• Which and how many material components are required in which time periods?
• Which operations are to be carried out at which work centers?

To use repetitive manufacturing (REM), various master data must have been created beforehand. The main master data required are:

• Materials
• Bills of material (BOM)
• Routings
• Work centers
• Production versions

The production of the bicycles is controlled by production orders in our bicycle company. However, since the same wheels are needed for different types of bicycles and the wheel production are quantity and period-oriented, it is decided to use repetitive manufacturing for the wheel production. In the material master of a product (finished product or semifinished material) that is to be manufactured in repetitive manufacturing, the repetitive manufacturing indicator must be set and a repetitive manufacturing profile must be assigned. As shown in the figure, the material master record for the wheel is configured accordingly.

The material components required for products are to be defined via bills of materials (BOMs). The bill of material (BOM) for a wheel manufactured in our bicycle company consists of the material components tire and rim.

Routings in repetitive manufacturing often have only one operation. You assign a work center representing the production line to this operation. Our bicycle company has two production lines for the production of the wheels. Therefore, as shown in the figure, two routings, Routing 1 and Routing 2, with the respective work centers, Assembly line 1 and Assembly line 2, have been created. The total production rate of a production line is specified in the respective operation. It defines how many products per time unit can be produced on this production line. The production dates, quantities, and capacity requirements of the planned orders are scheduled and calculated according to the production rate using formulas in the work center.

A planned order in repetitive manufacturing is created with reference to a production version of the corresponding product. A production version defines which routing in combination with which BOM is to be used for the planned order. If a planned order is to be used in repetitive manufacturing, the corresponding production version must be enabled for repetitive manufacturing and the work center of the routing must be assigned as a production line in the production version. 

As already mentioned, our bicycle company has two production lines for the production of the wheels. Therefore, as shown in the figure, two production versions 0001 and 0002 with the assignment of respective routings and the respective work centers as productions lines have been created. Both production versions are enabled for repetitive manufacturing. A suitable production version is automatically selected when the order is created according to criteria such as production quantity and production time. If several production versions are suitable, another production version can then be assigned manually, for example, in the planning table of repetitive manufacturing.

The repetitive manufacturing (REM) process can go through various steps from the creation of the requirements to the goods receipt confirmations of the produced quantities.

In a first step, based on the requirements (planned orders with order type Run Schedule Quantity (PE) are created as a result of material requirements planning.

If several production lines represented by several production versions are available, manual line loading can be carried out in the REM planning table. Here, the planned order quantities can be distributed to the production lines, simultaneously monitoring the respective capacity utilization.

To ensure that the required material components can be provided on time, the material availability check can be used.

Material staging is regularly carried out via stock transfers or Kanban.

During production, a reporting point backflush can be used to determine the work in progress.

Finally, goods receipt confirmations of the produced quantities with simultaneous backflushing of the components are posted regularly.

Each dependent requirement, that is, each material component of a planned order, can be assigned a default issue storage location. This default enables automatic replenishment and goods issue postings. It can be defined in the BOM, in the material master, or in the production version.

To organize material staging in repetitive manufacturing, SAP S/4HANA Cloud Public Edition provides the following options:

• Pull list

  With the help of the pull list, you can manually or automatically organize stock transfers from replenishment storage locations to issue storage locations in production.

  Note

  You define control data for stock transfers in the pull list in the configuration activity, Define Control Data for Pull List. This is explained in the next lesson.

• Kanban

  In Kanban, the material flow is organized using containers that are kept directly at the issue storage locations in production. Each contains the quantity of material that production line personnel need for a certain period of time. When a container is emptied, replenishment is triggered. Replenishment can be organized via stock transfers, in-house production, or external procurement. The production line personnel can use material from other containers until the actual container has returned full.

  Note

  The Kanban principle and Kanban configuration activities are discussed in the next unit.

When a goods receipt confirmation is posted with the confirmation, various actions are performed by default. These are largely controlled by the repetitive production profile. They include the following:

• An automatic goods receipt for the product is posted.

• Automatic goods issues for the components are posted (backflushing).

• The performed activities are confirmed.

• The planned order quantities and the associated capacity requirements are reduced.

• Actual production costs are posted to a product cost collector.

You have a long production line with a long lead time. However, the goods issues for the first components at work centers 1-1 and 1-2 are to be posted on-time and not by backflushing with final confirmation at the end of the production line.

Components used along a production line are backflushed during final confirmation. If there are long lead times, the goods issues for the components can be posted much later in the system than when they are physically withdrawn.

In this case, it makes sense to use the reporting point backflush to post the withdrawal of components (and production activities) at an earlier stage after successful completion of operations. The example contains the three reporting points that are linked to operations 10 (work center 1-1), 20 (work center 1-2), and 40 (work center 1-4).

Prerequisites:

In addition to activating the reporting point backflush in the repetitive manufacturing profile, ensure that the relevant work centers exist and that the required operations are available in the routing and defined as reporting points using the control key.

Depending on the application, you can use an optional or required reporting point confirmation.