Planning Horizon

Planning horizon is the number of days into the future that will be planned through Material Requirement Planning (MRP). It is usually expressed in number of working days but for purchased items, it can be in calendar days if the 'Settings – Purchasing' (CRS780) parameter ’33 Lead time days per week’ = 7.

The standard planning horizon is defined in 'Item. Connect Warehouse' (MMS002). It should not be longer than the accumulated critical lead time of the supply chain, possibly with some added safety time, if needed. This is sufficient for day-to-day MRP planning purposes.

The planning horizon can be automatically calculated with 'Planning Time Fence & Horizon. Calculate' (MMS355).

Avoid using an arbitrary planning horizon longer than necessary, especially for many items. This results to MRP calculations taking a longer time to finish because of these reasons:

MRP will be used to look further into the future, and read more forecast and material plan records.
More planned orders will be created or updated for future dates. This is especially significant if planned manufacturing orders are created by the MRP and the product structure has many material lines.

On the other hand, it is important that the horizon is not too short since this might cause shortages on future lower level demands.

If there is an occasional need to use a longer planning horizon, we recommend that you enable long-term planning.

Using Long-term Planning

The purpose of long-term planning is to break down next year’s budget or forecasted requirements for costing calculations or capacity control; or to generate planned POs to communicate to suppliers how much material will be required in the coming year.

Field	Usage
455 Long-term planning horizon	The number of days for the long-term planning horizon
460 Long-term planning horizon adjustment	Select the check box if parameter 455 should be added to the regular planning horizon.

To calculate MRP using the long-term planning horizon, start 'Material Plan. Re-calculate' (MMS999), and select the check box ‘Long-term planning’. The submitted job will automatically include all items due for re-calculation, especially those that are due for long-term planning.

Note: The long-term planning MRP re-calculation will take longer than the usual MRP job, and should not be scheduled more frequently than necessary. Once per week or maybe even once per month would suffice.