What-If and Scope

Honest Availability Scope

Availability here is deterministic arithmetic, not a reliability prediction.

highlighted = computed this step

Deterministic Snapshot

This snapshot uses only fixed MTBF and fixed MTTR inputs.

base availability=4/5what-if availability=8/9\text{base availability} = 4/5\quad\text{what-if availability} = 8/9
Maintenance availabilityThe chart compares the base cycle with the lower-MTTR what-if.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

Honesty Note

This is deterministic two-number availability arithmetic only. It does not model stochastic reliability, prediction, staffing, cost, root cause, repair logistics, or future performance.

availability here is deterministic two-number arithmetic\text{availability here is deterministic two-number arithmetic}
Maintenance availabilityThe chart compares the base cycle with the lower-MTTR what-if.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