What is the bathtub curve?

The concept of the bathtub curve is derived from the human life experience involving infant mortality, chance failures, plus a wear out period of life since data for births and deaths is accumulated by government agencies. Most equipment lacks the birth/death recording by government agencies and most non-human systems can be regenerated to live/die many times before relegation to the scrap heap.

Why use the bathtub curve?

Failure rates are different for both people and equipment at different phases of operation and the medicine to be applied to both humans and equipment need to be considered for effectively treating the roots of the problem.

When to use the bathtub curve?

The concept is useful during design, operation, and maintenance of equipment and systems to understand the failure mechanisms

Where to use the bathtub curve?

It explains the human experiences to the ordinary person to relate equipment/system failures to those experienced in real life so as to coordinate the design, operation and maintenance of equipment. For other definitions see MIL-HDBK-338, section 9.

These definitions are written by H. Paul Barringer

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