$1.$ Define the following terms:

$-$ Reliability:

$-$ Failure:

$-$ Downtime:

$-$ Maintainability:

$-$ Redundancy $($Active $\backslash$& Passive$)$:

$-$ Availability:

$-$ Mean time to failure:

$(21$ Marks$)$

$2.$ Discuss the need for reliability in engineering design and Maintenance activities:

$(6$ Marks$)$

$3.$ Produce a neat sketch of the bathtub curve.Identify and discuss the three main failure rate regions.