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Process documentation Project Manufacturing and Make-to-Order Manufacturing  Locate the document in its SAP Library structure

Purpose

In Production Planning and Detailed Scheduling (PP/DS), you can plan multi-level networks of orders for sales orders and project orders. This planning is supported by heuristics for scheduling and determining the critical path.

You can also achieve leeway in planning by inserting planning-related minimum intervals for relationships and planning-related offsets at requirements, that you can then reduce again, if necessary.

By analyzing the critical path (using a heuristic) in a network of orders, you can identify bottlenecks and reduce the network at suitable places.

The critical path is the part of the network that cannot be moved without resulting in a change to the end date of the project.

Because delays along the critical path lead to a delay of the entire project, you can reduce planning-related minimum intervals and planning-related offsets at operations that belong to the critical path.

If planning-related minimum intervals and planning-related offsets have been completely reduced and parts of the network still lie in the past, you can use the heuristic for forward scheduling to calculate a new end date.

Prerequisites

See Prerequisites

Integration

Planning-Related and Process-Related Minimum Intervals

When the ERP routing is used to create the SCM production data structure (PDS), planning-related and process-related minimum intervals are calculated from the data of the routing. Planning-related and process-related minimum intervals are adopted from the production data structure (in other words, the master data) when planned orders are created in SAP SCM.

If networks are used in ERP, the intervals defined in these networks are also transferred to SCM as process-related minimum intervals.

The data of the production data structure is filled from the routing data (wait time, move time, and queue time) on transfer from the ERP system. (See SAP Note 604878)

You can change the planning-related minimum intervals manually in the SCM system, in other words, in the order itself; this is not possible for process-related minimum intervals.

Background documentation

The planning-related intervals are mapped as follows in the PDS:

       The minimum interoperation time corresponds to the process-related minimum interval.

       The maximum interoperation time corresponds to the process-related maximum interval.

       The average interoperation time corresponds to the planning-related minimum interval.

Planning-related offset

The planning-related offset at requirements is not copied from the master data; instead, it must be created and changed in the SCM system.

When the PDS is created the operation lead-time offset of the ERP BOM item is used as the process-related offset.

For more information about integration, see the SAP Library under Supply Chain Management (SAP SCM) SAP Advanced Planning and Optimization (SAP APO) Industry-Specific Applications SAP for Industrial Machinery & Components Project Orders in SAP APO.

Constraints

      Sequence-dependent setup activities are not recommended for a process with infinite scheduling, because the heuristic for calculating the critical path may deliver incorrect results.

      A network of orders in SAP SCM is made up of sales orders or project orders, planned and production orders, and purchase requisitions that are linked via pegging relationships.

You should note that ERP collective orders - as before - are not transferred to SAP SCM as "whole objects" and are only available with the same scope of function as before. The order is integrated without fixed links between receipts and requirements.

      You should note that the project manufacturing heuristics (SAP_PMAN*) always schedule planned orders within the order validity, in other words, during scheduling no new source of supply is assigned, nor is a new explosion carried out.

Recommendation

Fixed pegging is recommended for the process.

Process Flow

The process is as follows:

This graphic is explained in the accompanying text

 

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       1.      Create sales order (ERP)

You create sales orders or project orders in the ERP system.

       2.      Transfer order (ERP SCM)

You transfer sales orders and project orders via APO Core Interface (CIF) to the SCM system where planning takes the orders into account as requirements.

       3.      Execute production planning (SCM)

You carry out infinite planning using a heuristic and create receipts to cover the requirements.

As a result of the production planning run the system creates a network of orders that covers the requirements of the sales or project orders.

Recommendation

For this process, SAP recommends that you use fixed pegging, that is, you should fix dynamic pegging relationships.

       4.      Create planning-related minimum intervals and planning-related offsets (SCM)

You create planning-related minimum intervals for relationships and planning-related offsets at requirements, to achieve leeway in planning. This creates a more "solid" plan that contains leeway for changes caused by a subsequent finite detailed scheduling run or for deviations during confirmation. You can reduce planning-related minimum intervals and planning-related offsets again, as necessary.

You can create planning-related minimum intervals and planning-related offsets manually or the system can create them automatically:

       Automatically

If you use the Business Add-In for Source of Supply Selection and Planned Order Creation /SAPAPO/RRP_SRC_EXIT, the system automatically creates planning-related minimum intervals and planning-related offsets when planned orders are created. (See Business Add-Ins for Project Manufacturing)

       Manually

For more information about manually creating planning-related minimum intervals and planning-related offsets, see Processing Planning-Related Minimum Intervals and Planning-Related Offsets

       5.      Execute backward scheduling (SCM)

After you have created planning-related minimum intervals and planning-related offsets, you carry out a backward scheduling run with the Heuristic for Infinite Backward Scheduling (SAP_PMAN_003).

The heuristic schedules the network of orders, taking into account the new planning-related minimum intervals and offsets and in this way adjusts the production plan to the new planning-related minimum intervals and planning-related offsets.

See Heuristics for Project Manufacturing, Heuristics and Detailed Scheduling Heuristics

       6.      Transfer data (SCM ERP)

Production execution takes place in the ERP system.

       7.      Calculate critical path (SCM)

If a delay occurs, you calculate the critical path using the Heuristic for Calculating the Critical Path (SAP_PMAN_001).

You can determine all operations in a multi-level network of orders that have floats (that is, the interval between the latest and the earliest start date) that are equal to zero or that fall below a certain threshold value.  These operations are regarded as critical. These operations do not necessarily have to follow one another. (See Heuristics for Project Manufacturing)

You can display these operations during execution of the heuristic.

       In the detailed scheduling planning board, the system highlights the operations that belong to the critical path with the color that has been defined in the planning board profile.

       You can also display all operations of the selected network as a list. The critical operations are highlighted in this list.

(See Display Critical Path as List)

Note

Partially confirmed operations are fixed and therefore, are taken into account during scheduling, but are not rescheduled. If you want the system to schedule these operations, you must interrupt these operations, in other words, you must remove the fixing of these operations.

       8.      Reduce planning-related minimum intervals and planning-related offsets (SCM)

You reduce planning-related minimum intervals and planning-related offsets along the critical path. (See Display Critical Path as List)

       9.      Execute backward scheduling (SCM)

You carry out a backward scheduling run with the heuristic SAP_PMAN_003, to schedule the network of orders, taking into account the new planning-related minimum intervals and planning-related offsets.

After backward scheduling, the following situations may arise:

       The network lies in the past and planning-related minimum intervals and planning-related offsets exist

In this case, you calculate the critical path (step 7) again and reduce planning-related minimum intervals and planning-related offsets (step 8). You then carry out a backward scheduling run (step 9).

Carry out steps 7, 8 and 9 until the network no longer lies in the past and the planning-related minimum intervals and offsets are reduced to zero or correspond to the process-related minimum intervals. (The planning-related minimum intervals cannot fall below the process-related minimum intervals).

       The network lies in the past and planning-related minimum intervals and planning-related offsets have been used up

In this case, you use the Heuristic for Infinite Forward Scheduling (SAP_PMAN_002) to calculate a new end date.

   10.      Execute forward scheduling (SCM)

You use the heuristic for forward scheduling (SAP_PMAN_002) if it is no longer possible to meet the deadline for the project or sales order. This may be the case if the network of orders lies partially in the past and any planning-related minimum intervals and planning-related offsets have already been used up, with the result that you have to calculate a new end date.

(See Heuristics for Project Manufacturing)

Note

Before you carry out forward scheduling, you can, if you wish, insert new planning-related minimum intervals and planning-related offsets.

The planner must also manually adjust the sales order date in the linked ERP system; adjustment is not carried out automatically.

 

For more information about the business process, see the SAP Help Portal, at the Internet address www.help.sap.com Documentation SAP Solution Manager Business Scenarios and Cross-Industry Processes SAP for IM&C: Business Scenario Descriptions Link to external website Project Manufacturing.

 

 

 

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