,
,BATH TUB CURVE
Most products go through three distinct phases from product inception to wear out. Figure below
shows a typical life cycle curve for which the faiure rate is plotted as function of time.
Infancy / Green / Debugging / Burn-in-period: Many components fail very soon after they are
put into service. Failures within this period are caused by defects and poor design that cause an
item to be legitimately bad. These are called infant mortality failures and the failure rate in this
period is relatively high. Good system vendors will perform an operation called "burn in" where
they put together and test a system for several days to try to weed out these types of problems so
the customer doesn't see them.
Chance failure / Normal Operating Life: If a component does not fail within its infancy, it will
generally tend to remain trouble-free over its operating lifetime. The failure rate during this
period is typically quite low. This phase, in which the failure rate is constant, typically represents
the useful life of the product.
Wear out / Ageing: After a component reaches a certain age, it enters the period where it begins
to wear out, and failures start to increase. The period where failures start to increase is called the
wear out phase of component life.
,
,BATH TUB CURVE
Most products go through three distinct phases from product inception to wear out. Figure below
shows a typical life cycle curve for which the faiure rate is plotted as function of time.
Infancy / Green / Debugging / Burn-in-period: Many components fail very soon after they are
put into service. Failures within this period are caused by defects and poor design that cause an
item to be legitimately bad. These are called infant mortality failures and the failure rate in this
period is relatively high. Good system vendors will perform an operation called "burn in" where
they put together and test a system for several days to try to weed out these types of problems so
the customer doesn't see them.
Chance failure / Normal Operating Life: If a component does not fail within its infancy, it will
generally tend to remain trouble-free over its operating lifetime. The failure rate during this
period is typically quite low. This phase, in which the failure rate is constant, typically represents
the useful life of the product.
Wear out / Ageing: After a component reaches a certain age, it enters the period where it begins
to wear out, and failures start to increase. The period where failures start to increase is called the
wear out phase of component life.
,
