EXTERNAL Failure cost RELIABILITY EXERCISE

Over the past $5$ years $(2000-2004),$ there have been $15$ power outages at our workplace. A log

has been kept of the outages showing the time of each outage. They were:

$17$ mins, $3$ mins, $1hr5$mins,$1$min,$45$mins,$2hrs20$mins,$2$ mins, $5$ mins, $14$mins,$2$mins,$4$

mins, $31$ mins, $4$ mins, $20$ mins, $7$ mins. $($total $360$ minutes$)$

During this time, there was one planned, and well advertised, outage in order to yrgade the

building electrical inlet cable. Power was off for $6$ hours on a Sunday morning while the

upgrade took place.

Calculate the Mean Time Between Failures $($MTBF$),$ the Mean Time To Repair $($MTTR$)$ and

the Availability of power.

MTBF hint: Total run time$/$number of failures

MTTR hint: total downtime$/$ number of failures

$\backslash$table$[[$Item Description,Ist Quarter,$\backslash$table$[[2^($vd $)],[$Quarter$]],3^($rd $)$

Quarter $,\backslash$table$[[4],[$Quarter$]],$Full Year$],[$Average no units in use,,,,,n$/$a$],[$Average run hours per unit,,,,,n$/$a$],[$Total Run hours,,,,,n$/$a$],[$Projected failures,,,,,n$/$a$],[,,,,,],[$Product cost per unit,,,,,n$/$a$],[$Shipping costs per unit,,,,,n$/$a$],[$Failure cost per unit,,,,,n$/$a$],[$Failure cost$,,,,,],[,,,,,],[$Recall:$,,,,,],[$No of units,,n$/$a$,$n$/$a$,$n$/$a$,],[$Costs per unit,,n$/$a$,$n$/$a$,$n$/$a$,],[$Recall cost$,,$n$/$a$,$n$/$a$,$n$/$a$,],[,,,,,],[$External Failure Cost,n$/$a$,$n$/$a$,$n$/$a$,$n$/$a$,],[,,,,,],[$Qty sold,,,,,$],[$Sales revenue,,,,,$],[,,,,,],[\%$ of sales,n$/$a$,$n$/$a$,$n$/$a$,$n$/$a$,]]$

Hint: The average number of units in use is the number at the start of the quarter plus the number at the end of the quarter divided by $2.$