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Without historical lifecycle data, we cannot make objective decisions about machines. To determine a critical machine’s availability, we need to know how long it ran between outages and how long it took to make repairs. Therefore, we need a database that can capture life cycle events for all your critical machines.

Consider the life cycle of the hypothetical machine seen in Figure 2.7. At t₁ the machine is started for the first time. The machine runs reliably from time t₁ to t₂ and fails. The machine is repaired from time t₂ to t₃ and then restarted at time t₃. The machine runs from t₃ to t₄ and fails. The machine is repaired from time t₄ to t₅ and then restarted. The machine runs from t₅ to t₆ and fails at time t₆. The machine is repaired from time t₆ to t₇ and then restarted.

All of these start-up and shutdown times should be captured in machine records. In addition to these times, you also need to record:

 Repair or PM work scope performed during downtimes.

 Denote of the outage was planned or unplanned.

 Repair costs.

 Root causes of unplanned work.

 Losses incurred as a result of an unplanned outage. Losses can be related to production losses, demurrage, fines, etc.

If all this information is available, then the machine’s availability (A_o), MTBF, MTTR can be determined and trended.

Some other tools used to track critical machines are: