Pull planning

The Planner pull plans an order in this order:

• Planned supplies of the end item are allocated to satisfy the demand quantity
• For any unsatisfied demand quantity, on-hand inventory is allocated. If sufficient planned supplies are available or sufficient inventory is on hand to satisfy the order, the planning is complete
• If unsatisfied demand quantity remains, a manufacturing order or purchase order is planned for the remainder. This step varies according to the type of item being planned:
  • Unconstrained items (zero lead time) require no further planning. An item is unconstrained if the MATL.FLAGS bit5 is enabled. The Planner plans the demand at the requested date, and assumes it to be satisfied.
  • The Planner plans the operations through the routing, starting with the end item’s last operation, considering material and resource availability and WIP at each operation. All combinations of resources are considered until the fastest combination is found (unless you have limited the number of combinations through the ALTPLAN.PULLITERS parameter). The pull-planning fails if the Planner is unable to plan any given operation with enough time remaining to plan all remaining upstream operations. At any point, if enough WIP is found to satisfy demand, the pull is complete and successful. After successfully pull-planning the current item through its routing, the Planner considers that item’s components. From this point, it recursively pull-plans each component. If any item’s plan extends into the past, all pull planning for the order fails and the Planner switches to push planning.
• If the item has an order minimum value specified (MATL.ORDMIN), and the quantity the Planner plans to make or purchase will satisfy the entire demand quantity, it then frees the supply and inventory allocated in step 1.