What is MTBSO?

Why use a MTBSO (Mean Time Between Stock-Out) goal? Why not use Stock-Out-Risk or Availability? Problem a) No Time-Frame Often requirements documents will specify something like, “spare parts availability shall be 95%”. What does this mean? Nothing. For an...

How to Calculate NFF Ratios

How to calculate the No Fault Found Ratio for a Line Repairable Unit. Background Technicians often remove Line Repairable Units (LRUs) when there is nothing wrong with them. If they send the LRU back to the service centre and it is diagnosed as serviceable this is...

Spares Calculator Terms

Availability Availability is the probability that a spare part will be available in the spares pool when demanded to carry out a repair during the Repair Delay period. For example, a stock-holding of 10 spare parts might have an Availability probability of 90% in a...