MTBF, MTTR, and Cycle

Cycle Time

The cycle adds uptime and repair time before any ratio is taken.

highlighted = computed this step

Cycle Time

One cycle is uptime plus repair time: 50 hours.

40+10=5040 + 10 = 50
Cycle timeCycle time adds uptime and repair time.availability cycleMTBFMTTRcyclebase401050

Cycle Picture

The same cycle appears as an uptime segment followed by a downtime segment.

cycle=50\text{cycle} = 50
Maintenance availabilityThe chart shows uptime and downtime in one deterministic cycle.maintenance availabilitycycle 50; availability 4/5; downtime 1/5caseMTBFMTTRcycleavailabilitydowntimebase4010504/51/5what-if405458/91/9baseup 40down 10cycle 50what-ifup 40down 5cycle 45what-if MTTR 5; availability gain 4/45deterministic two-number availability arithmetic only