The Oracle planning process explodes through the bill of material to generate component requirements by evaluating:
# bills of material
# scheduled receipts
# on–hand inventory balances
# lead times
# order modifiers
It then calculates time–phased material requirements. Each item may have different attributes that affect the recommendations generated by the planning process.

MPS Plan Generation
You can launch the planning process for an MPS plan from a master demand schedule. This generates an MPS plan for all your MPS planned items. Oracle Master Scheduling/MRP and Supply Chain Planning also plans any MRP planned items that have an MPS planned component. This ensures that all derived demand is correctly passed down.
Once you have generated an MPS plan, you can make a copy of the plan that is identical to the original. You can then view, implement, and replan either copy, discarding the altered plan at any time and preserving the original data.

Plan Options

Overwrite
All: For an MPS plan, overwrite all entries and regenerate new MPS entries based on the source master demand schedule.
For an MRP, overwrite all planned orders and MRP firm planned orders for MRP items. This option is displays when you generate a plan for the first time.
Outside planning time fence: For an MPS plan, overwrite all MPS entries outside the planning time fence.
For an MRP, overwrite all planned orders and firm planned orders outside the planning time fence.
None: Do not overwrite any firm planned orders for MPS or MRP plans and net change replan.

Append Planned Orders
Check Append Planned Orders to append new planned orders in the following situations:

If the MPS plan name has an existing schedule associated with it and you enter None as the overwrite option, the planning process does not recommend rescheduling or suggest new planned orders before the end of the existing MPS (the last planned order) even if so indicated by new demand from the master demand schedule. This is analogous to firming your master production schedule. By not overwriting, the master scheduler is taking responsibility for manually planning items. For an MRP plan name, this option creates planned orders where needed, considering existing MRP firm planned orders.
Note: If you want to add firm planned orders using net change replan, set the overwrite option to Outside planning time fence or None.

If the plan name has an existing MPS or MRP associated with it and you enter None as the overwrite option and do not check this, the planning process reports the instances where the plan is out of balance with the source master schedule. It does not recommend any new orders. Instead it lets you manually solve any problems in the process. This gives maximum control to the master scheduler and/or material planner.

If the plan name has an existing MPS or MRP associated with it and you enter All as the overwrite option, the planning process deletes all previous planned entries and creates new planned orders based on the source master schedule.

If the plan name has an existing MPS or MRP associated with it and you enter Outside planning time fence as the overwrite option, the planning process deletes all planned entries after the planning time fence and creates new planned orders after that date. In this case, since you are overwriting after the planning time fence, you are also appending new planned orders after that date.

Check Snapshot Lock Tables
Check Snapshot Lock Tables to indicate whether tables are locked during the snapshot process to guarantee consistent data. This option temporarily prevents other users from processing certain transactions.

Demand Time Fence Control
Check Demand Time Fence Control to indicate whether the planning process considers any demand from forecasts within the demand time fence. The planning process does not consider demand from forecasts within the demand time fence, but considers demand from sales orders.

Check Planning Time Fence Control
to indicate whether the planning process violates planning time fences for items. For discrete items, the planning process does not create planned orders or recommend to reschedule in existing orders within the planning time fence of the item. The planning process can still recommend to reschedule orders out.
For repetitive items, the planning process can vary the suggested schedule from the optimal schedule, within the planning time fence, by the acceptable rate increase and/or decrease you specified for the item.

Net WIP
Check Net WIP to indicate whether the planning process considers standard discrete jobs, non–standard discrete jobs, or repetitive schedules when planning items during the last plan execution.

Net Reservations
Check Net Reservations to indicate whether the planning process considers stock designated for a specific order when planning the items during the last execution of the plan.

Net Purchases
Check Net Purchases to indicate whether the planning process considers approved purchase requisitions when planning the items during the last execution of the plan.

Plan Safety Stock
Check Plan Safety Stock to indicate whether the planning process calculates safety stock for each item during the last plan execution.

Planned Items
Specify which planned items or components you want included:

• All planned items Include all planned items in the planning process. You would chose this option to be certain that all item are planned, such as those you add to a job or schedule that are not components on any bill.

Note:
i. You may want to plan using this option to avoid missing items you want to plan. For items you do not want to plan, define them with an MRP planning method of Not planned when you define an item in Oracle Inventory.
ii. Note: If you are launching the planning process for a master production schedule, you cannot edit or enter data in MDS/MPS components fields.

• Demand schedule items only
• Supply schedule items only
• Demand and supply schedule items

MRP Generation
You can launch the planning process for an MRP plan from a master demand schedule or a master production schedule. This generates planning recommendations for all planned items. Once you have generated an MRP plan, you can make a copy of the plan that is identical to the original. You can then view, implement, and replan either copy, discarding the altered plan at any time and preserving the original data.

From a Master Demand Schedule
If you do not need to smooth production or otherwise manually manipulate a master production schedule, you can generate a plan directly from a master demand schedule. The planning process overrides the MRP planning method and treats MPS planned items as MRP planned items, DRP planned items, or DRP/MRP planned items. As a result, the planning process generates planned orders and reschedules recommendations for your MPS, MRP, and DRP planned items.

From a Master Production Schedule
You can also generate an MRP plan from a master production schedule. For each MPS planned item, the planning process considers projected gross requirements, current orders for the item, the master production schedule, and on–hand quantities over time. The planning process calculates the projected quantity on hand and generates exception messages to signal any potential imbalances in the material plan. By default, the planning process generates firmed planned orders for MPS planned items.