Repetitive Manufacturing with iPPE 
This process describes how to execute Repetitive Manufacturing in APO on the basis of the integrated Product and Process Engineering. Scheduling in APO using this process is carried out as takt-based scheduling. You can also directly enter the backflush data for the production backflush in APO. The backflush data is then posted in the DI System. This procedure is very fast and is therefore ideal for planning products with a large number of components.
You can only use this planning process if you use APO along with a Discrete Industries System as iPPE is only supported in the DI System and in APO.
You can use this process for make-to-stock production and for make-to-order repetitive manufacturing with configurable products:
A make-to-stock production environment in Repetitive Manufacturing exists if you produce products in large quantities with the same production procedure in unlimited lots. Here, production is carried out with no reference to the sales order. The planned independent requirements are created in Demand Management in the DI System or in Demand Planning in APO. Incoming sales orders are delivered from warehouse stock and the sales order quantities consume the planned independent requirements quantities according to the selected planning strategy. Planning is based on these two requirements (sales order quantities and planned independent requirements).
You can also use this process to plan products with multiple variants and a very large number of orders such is common in the automotive industry, for example. Here, production is executed with direct reference to the sales orders. That is, the sales orders are used as the basis for planning. The planned orders for the product ordered by the customer and for important components are assigned to the account of the sales order for which they are required.
Note
Working with this process has the disadvantage that you cannot use pull lists, event-controlled kanban or kanban with planned orders for the products.
In the DI System and in APO, you must maintain the technical settings required to create the basis for setting up the interface between the two systems. You can find the individual steps from the document Checklist for Setting Up the System Landscape. For more information, refer to the documentation Integration of APO and R/3.
The following diagram shows the planning process for repetitive manufacturing for configurable and non-configurable products with APO and a DI System:

Maintain all the necessary master data in the DI System and then transfer this data to APO using the APO Core Interface. See also Transferring iPPE Data to APO.
In SAP APO, you generate a production data structure (PDS) from iPPE data. This production data structure is used as the basis for planning in SAP APO. See also: Generating Production Data Structures (PDS) from iPPE Data
Maintain the PP/DS settings in APO, such as the factory calendar, propagation range, and so on.
Transfer the necessary transaction data (for example, sales orders, planned independent requirements, stocks) to create a consistent planning situation between the two systems.
Execute a planning run in APO for the product to be planned:
Configurable Products
To plan configurable products, you can carry out the planning run in Model Mix Planning. In Model Mix Planning, depending on your settings, an APO planned order with order quantity 1 is created for every sales order. In Model Mix Planning, the planned order is assigned to a line resource on which final assembly is to be carried out and the order sequence is determined with specification of the start and finish dates of the planned orders. This APO planned order contains no component list if, for the product to be planned, you set that explosion is to be carried out using the planning matrix. In the last step, the planning run in Model Mix Planning explodes the product variant structure and creates a planning matrix. Now, the planning matrix determines the requirement quantities and dates of the required components. This process is very fast. In just a few minutes, you can process several thousand orders.
As an alternative to the procedure described above, you can also carry out a single explosion of iPPE after Model Mix Planning if you set single explosion of the iPPE data for the product to be planned. Or you do not use Model Mix Planning and carry out a planning run in Production Planning. In this planning run, APO planned orders are created for the product to be planned and a single explosion of iPPE is carried out to determine the components required for the finished product - if you set single explosion of iPPE for the product to be planned.
Non-Configurable Products
To plan non-configurable products, carry out a planning run with REM Heuristics, for example. Two heuristics are provided specifically for repetitive manufacturers. Both heuristics create APO planned orders for the existing requirements while taking the free capacity of the resources into account per period. In the next step, the planning run executes a single explosion of the iPPE data to determine the requirements quantities and dates of the necessary components.
If necessary, you can also define further heuristics for planning the lower-level BOM levels which means you can plan all BOM levels in one planning run. However, planning is only executed for the components which you have defined to be further planned in APO. In this case, APO also creates suitable planned orders for the dependent requirements. You can also execute this planning step in a separate planning run as described in step 7.
Evaluate the planning results:
In the short-term planning period, you can use the sequence schedule to evaluate the planning results of Model Mix Planning (for configurable products). In the sequence schedule, you can display and change the sequence of the dispatched planned orders. You can also use the product planning table. To evaluate the planning results of the non-configurable products, use either the product planning table or the product view.
Less important components (B and C parts) should not be further planned in APO but in the DI System - when planning these parts, you do not usually require any planning functions other than those in this system. Here, the procedure is as follows:
The planning file entries of these components are automatically transferred to the DI System.
For these components you carry out MRP in the DI System. MRP transfers the dependent requirements of the components in APO by means of the Remote Call Function (RCF).
You evaluate the results of MRP using the MRP list or the stock/requirements list.
The components are produced/procured in the DI System. This means you convert the planned orders or purchase requisitions created in APO to cover the dependent requirements, if necessary, carry out backflushing, post goods receipts and issues and so on.
You continue to plan the important components produced in-house or procured externally (A parts) - such as the engine in the automotive industry - in APO.
You carry out a planning run in APO for these components. The planning run creates APO planned orders to cover the dependent requirements determined in APO. In the planning run a single explosion of the iPPE data is carried out for components produced in-house to determine the dependent requirements for the lower-level components.
You evaluate the planning results for the finished product and for the components which you continued to plan in APO and, if necessary, process the procurement elements created in APO. To do this, you can use the product planning table or the product view, for example.
Now, you can transfer the APO planned orders for the components to the DI System where they are produced/procured (conversion, backflush and so on).
or
You can process the APO planned orders or APO purchase requisitions for the externally procured components using collaborative procurement directly in APO and convert them into purchase orders. Collaborative procurement provides you with support in determining the supply source, when using delivery schedules and so on.
You plan and control the production of the finished product (final assembly) in APO - with the help of the product planning table and sequencing (only for configurable products). You also create the production backflush in APO. The backflushing data is transferred to the DI System. Here, the goods receipt of the finished product and, at the same time, the goods issue of the components are posted automatically (backflush). However, you can also cumulate the goods issues and post them later. The updated component stock levels are transferred from the DI System to APO. The dependent requirements are updated in APO simultaneously. That is the component requirements are reduced. See also: Production Backflush.