Question
Using availability = MTBF / (MTBF + MTTR), a system has mean operating time between failures (MTBF) of 1 day and target availability of 99.99%. What is the corresponding mean repair time (MTTR), rounded to the nearest whole second?
The correct answer is
9 Seconds
\(MTTR=MTBF\frac{1-A}{A}=86400\frac{0.0001}{0.9999}\approx8.640864\text{ seconds}.\)
Rounded to the nearest whole second, this is 9 seconds. The unrounded repair-time allowance is about 8.64 seconds.
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Important Questions from Quality Control - Teaching
- Assertion (A) : Clean-in-place method of cleaning requires no disassembly or only partial disassembly of equipment.
Reason (R) : The pieces of equipment are cleaned and sanitized by circulation of chemical compounds through a piping system in clean-in-place method.
Codes : - Which is the correct danger zone in food production ?
- Some tools needed for problem solving are :
(a) Pareto chart
(b) Check sheet
(c) Profit and loss statement
(d) Cause and effect diagram
(e) Standardized recipes
(f) Process chart An X̅ chart uses the following data
- $\bar{X}$ and R-charts are for which of the following ?
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