Infinite master planning
In infinite master planning, LN generates a supply plan without taking into account any capacity or material constraints. Therefore, this planning method is comparable to the traditional MRP II planning paradigm.
Infinite planning is especially suitable in situations where the amount of available capacity and the availability of materials for production can easily be expanded when necessary.
Inifinite planning is the default planning method in master planning. It is used for:
- Plan items which have not been linked to a specific plan unit.
- Plan items which have been linked to a plan unit in which Infinite Planning is the master-planning engine used.
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The choice of master-planning engine only makes a difference for production planning. Purchase planning and distribution planning are always carried out in the same way, regardless of whether infinite planning or workload control is used as the master-planning engine.
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Below you can find an overview of the planning procedure used for infinite planning (and playing a role in workload control as well - see Workload control. For a step-by-step description of the way item master plans are updated, see also To update master-plan data.
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Production and purchase are only used as supply sources if the Automatic Update of Production Plan or Automatic Update of Purchase Plan field in the Items - Planning (cprpd1100m000) session is set to either Generate or Always Update.
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ATP data is only maintained within the CTP Horizon.
Planning procedure
During a master-plan simulation in the Generate Master Planning (cprmp1202m000) session or the Generate Master Planning (Item) (cprmp1203m000) session, LN generates a supply plan to meet the demand in a plan period and to reach the inventory target expressed in the inventory plan.
The procedure is roughly similar to the procedure for updating an item master plan (see To update master-plan data. There is one major difference. In the update procedure the projected inventory is simply recomputed, A simulation, on the other hand, involves detecting shortages in the projected inventory, and generating a supply plan to cover these shortages.
A supply plan is only generated within the item's master-planning horizon.
Determining the required supply
For each plan period for which supply has to be planned, the required quantity has to be computed. First, the expected inventory level at the end of the period is computed. For the basic procedure, see To compute the projected inventory. Keep in mind, however, that in this stage of the computation, the supply plan quantities that have to be recomputed are ignored (in other words, set to zero). This means that:
- The planned distribution orders are ignored (these are always regenerated during a master-plan simulation).
- The production plan is ignored if the Automatic Update of Production Plan field in the Items - Planning (cprpd1100m000) session is set to Generate or to Always Update.
- The purchase plan is ignored if the Automatic Update of Purchase Plan field in the Items - Planning (cprpd1100m000) session is set to Generate or to Always Update.
If the expected inventory level thus computed is equal to or higher than the inventory plan for the plan period in question, no more supply needs to be planned for this plan period. In this case, the planning algorithm proceeds to the next period.
If the expected inventory level is lower than the inventory plan, the difference between the two is the quantity for which a supply plan must be generated.
Selecting sources of supply
For the supply that is to be planned, the planning system has to determine which sources to use (production, purchase, distribution, or a combination of these), and how to divide the supply over these sources. This is done according to the sourcing settings that have been recorded for the item involved. For more information, see Sources of supply.
Depending on these sourcing settings, the supply plan quantity is allocated in one of the following ways:
- Only one source is used for supply (either production, purchase, or distribution).
- The supply is divided percentage-wise over two or three different sources.
Recomputing projected inventory and ATP
After the supply plan has been updated, the projected inventory is recomputed (see To compute the projected inventory.
Moreover, the ATP and the cumulative ATP are recomputed (see Computing item ATP.