Answer ALL Questions $[10]$

The MTBF will increase if the producer succeeds in lowering either the failure rate or the number of failures

$T$

F

Which of the following statements about preventive maintenance is true?

A$.$ Maintenance is carried out at predetermined intervals

B$.$ Maintenance is carried out according to prescribed criteria

C$.$ Maintenance is carried out in order to reduce the probability of failure

D$.$ All of the above

E$.$ None of the above

Which of the following is a component of the unplanned downtime losses?

A$.$ Equipment breakdown

B$.$ Changeovers

C$.$ Lack of material

D$.$ All of the above

E$.$ None of the above

$($Down time in hours $/$ Available hours$)=$

A$.$ Maintenance Engineering

B$.$ Frequency of breakdown

C$.$ Effectiveness of maintenance planning

D$.$ All of the above

E$.$ None of the above

The down time cost consists of

A$.$ Loss of production

B$.$ Wages paid to the workers

C$.$ Reduction in sales

D$.$ All of the above

E$.$ None of the above

Suppose that a certain product has a meantime between failure of $1000$ hours, and the has a mean time to repair of $20$ hours. If the product is used by $100$ customers, what is its availability?

A $80\%$

B$.90\%$

C $98\%$

D $99\mathrm{.}8\%$

E$.100\%$