MRR6

MRR6 (Maintenance Replacement Rate per million hours) （百万時間あたりの交換率）

MRR6 is an input variable (Parts, or End Item/Part Data) that provides an estimate of the maintenance replacement rate per million operating hours of one unit of the item on a single end-item or system. This assumes that the gross failures have already been reduced to reflect any No Fault Found rate (NFF) or Repair in Place rate (RIP). Note that MRR6 should not be increased to reflect a Quantity per Next Higher Assembly (QPA) greater than one. TEMPO does perform the multiplication by QPA when it calculates the annual demand (AD).

MTBF (Mean Time Between Failures) can be used instead of MRR6, but at least one of these two variables must be present for each item. In the event that both are entered, TEMPO uses MRR6.

When there is a common item (SRU or sub-SRU), both QPA and MRR6 may differ from one appearance of the common item to another. All other variables (e.g. item price, NRTS rates , initial stocks, etc.) are entered with the defining item and cannot assume different values for any referring item. The reason that QPA and MRR6 can change is that they depend on the relationship of the item to its parent. It is possible for the demand rate per unit of an SRU in one LRU to be different from the demand rate per unit of that same SRU in another LRU.

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