Modeling Production Lead Time

You can freeze a supply plan for the first few periods of the planning horizon to ensure that planning runs don’t affect decisions already made, which are firmly planned and irreversible.

The length of time for which you freeze the supply plan is called the freeze horizon (it can be, for example, the first three periods).

You would typically need a freeze horizon after integrating with an external planning system such as SAP SCM-APO, SAP ERP, or SAP S4/HANA, because you don’t want your supply plan to override supply decisions taken by the external planning system for the first few periods.

During the freeze horizon, the time series based heuristics planning algorithms shouldn’t override the following fixed supply elements:

• Production quantities

• Transport quantities

• Procurement quantities

Outside of the freeze horizon, the time series based heuristics planning algorithms carry on planning in the unfrozen periods, as normal.

You can specify the length of the freeze horizon in the following attributes:

• Attribute PFREEZEHORIZON of the Production Source of Supply Header master data type (SOURCEPRODUCTION) for production sources of supply or external sources of supply.

• Attribute TFREEZEHORIZON of the Location Source of Supply master data type (SOURCELOCATION) for location sources of supply.

A value greater than zero specifies the length of the freeze horizon in days. This value is rounded to planning periods.

Inside the freeze horizon, infinite heuristics supports the freeze horizon and confirmed key figures (Confirmed Production, Transport and External Receipts), and always ignores values in adjusted, minimum, and maximum key figures.

Outside the freeze horizon, infinite heuristics treats confirmed key figures in the same way as minimum key figures.

To model production processes that take longer than one planning period, you can specify the production lead time for production sources of supply. The production lead time can be a day, week, month, or quarter, depending on the planning granularity.

Production lead time is the number of planning periods that it takes to finish a production process, not including the period in which a process starts. For example, if a production process takes four planning periods, the production lead time is three planning periods. If a production process is completed in one planning period, the production lead time is zero.

You can define a capacity consumption policy for production sources used in the production process. You can also specify a component offset for components. This defines the planning period in which the component is consumed by the production process.

To define production lead time, you use the Production Lead Time (PLEADTIME) master data attribute.

Use this attribute to specify the duration of the production lead time as a number of planning periods. You assign it to the master data type SOURCEPRODUCTION (header).