Related Topics:
	Spare Part Pools

Spare Part Pools - Simulation Assumptions

The underlying simulation assumptions for spare parts are:

• Spare parts are always required for corrective and preventive tasks.

• If a spare part pool has not been assigned to the task, then it is assumed that unlimited free spares are always available.

• Spare parts are never required for inspection tasks.

• All restocking that occurs during simulation is based on the settings of the spare part pools.

• If the Restock as needed check box is selected, a restock will be triggered every time a part is taken from the spare part pool and the number of items in the pool drops below the limit specified in the Restock when stock drops to field.

• If the Scheduled Restock and Restock as needed check boxes are selected, then if a spare part from a scheduled restock can arrive before a spare part from an on condition restock, the spare part from the on condition restock will not be called upon.

• A block that triggers an emergency restock is charged for the additional emergency cost, even if it did not use the restock part(s) (e.g., another part became available from a scheduled restock first).

• The average stock level (ASL) metric in the simulation results is based on how many times the stock level was determined (e.g., every time a request is made, whether it is rejected or accepted, etc.). The average stock level is recorded at the beginning and at the end of each simulation.

In addition, the following underlying simulation assumptions also apply to off-site spare parts:

• The spare acquisition time for both the on-site pool and off-site pool is taken into consideration when a block orders a spare part. If the off-site spare part will not arrive before the simulation end time, the block will not order it.

• If the off-site emergency spare part will not arrive before the simulation end time, neither the on-site pool nor the off-site pool will order it. However, an on condition restock will be performed as long as the part from the off-site pool will arrive at the on-site pool before the simulation end time.