Time fence control is a policy or guideline you establish to note where various restrictions or changes in operating procedures take place. For example, you can easily change the master production schedule for an item beyond its cumulative lead time with little effect on related material and capacity plans. However, changes inside the cumulative lead time cause increasing difficulty, reaching a point where you should resist such changes because of their effect on other plans. You can use
time fences to define these points of policy change. Oracle Master Scheduling/MRP and Supply Chain Planning offers three types of time fences:

• planning time fence
• demand time fence
• release time fence

Planning Time Fence
For discrete items, you can recommend that an order be rescheduled out or cancelled, but cannot recommend reschedule in messages or create new planned orders within the planning time fence for an item.
For repetitive items, you can limit the changes Oracle Master Scheduling/MRP and Supply Chain Planning can recommend within the planning time fence by the acceptable rate increase or decrease.
The planning time fence does not apply to purchase requisitions or internal requisitions.

Demand Time Fence
If you specify demand time fence control when launching the planning process, the planning process only considers actual demand within the demand time fence specified for an item (such as forecasted demand is not considered).

Release Time Fence
If you define a release time fence attribute for your item, and you specify release time fence control when defining a DRP, MPS or MRP name, you can automatically release planned orders as WIP jobs.
Planned orders for purchased items are released as purchase requisitions. The planned orders must meet the following auto–release criteria:

•  new order placement date within the auto–release time fence
•  must not have compressed lead time
•  must be for standard items (the planning process will not automatically release models, option classes, and planning items)
•  the orders are not for Kanban items

Auto–release Planned Orders
Instead of implementing and releasing planned orders by hand, you can enable the planning process to automatically release planned orders. During the planning run, all qualifying planned orders that fall within the release time fence will be released. Unlike manual release, you cannot modify order dates and quantities or the default implementation details.

Before the planning process can release planned orders automatically, you must:

• Define an employee, associate a user name to the employee entry, and associate the employee to the application user.
• Define a planner or planning entity and associate this planner with items you want controlled by the auto–release function.
• Supply Chain Planning users must define a material planner, supply chain planner or planning entity for the current organization and assign them to inventory items at the organization level.
• Define Default Job Status and Job Class values for a user on the Planner Workbench Preferences window. These settings are in theSupply/Demand region and are used as defaults in the process of automatically releasing planned orders.

In addition, the planned orders must meet the following auto-release criteria:

• The new due date lies within the auto-release time fence and the release time fence option is defined as anything other than Do not auto-release, Do not release (Kanban), or Null
• The lead time is not compressed.
• The orders are for standard items (will not release models, option classes, and planning items).
• The orders are not for Kanban items.

To enable the auto-release function:
1. Use release time fence.
2. Navigate to the DRP, MPS, or MRP Names window and Check Production to enable a plan to auto-release planned orders.
3. Select Yes to enable the Memory-based Planning Engine. You must enable the Memory-based Planning engine to use the auto-release function.
Auto-release of repetitive schedules is not applicable to repetitively planned items. No material availability check is performed before WIP jobs are released.