3-5 Bath-tube curve

bathtub curve Plant Management

Bath-tube curve

The frequency of facility failures is higher at the beginning stage and at the later stage of its life cycle.

If you plot the frequency of facility failures over time the chart looks like a bathtub.
Thus the shape is called the bathtub curve. The early stage of facility failure is called the initial failure period. Later. the facility begins to function to its full performance and facility troubles become less. with sporadic failures only. This stage is called the sporadic failure period. Later in the life cycle is called the worn out failure period, since there appear frequent facility failures due to the wearing out and degradation of facility.
The measure to be taken to reduce failures is different depending on the stage of the facility life cycle  However.It is important to take measures so that the bottom of bath tub becomes lower and the length of sporadic failure period longer .It is important to use old degraded machines for training, test production and for maintenance.

Related Terms:Initial failure, Sporadic failure, Worn- out failure

bathtub curve