thumb|right|350px|The 'bathtub curve' hazard function (blue, upper solid line) is a combination of a decreasing hazard of early failure (red dotted line) and an increasing hazard of wear-out failure (yellow dotted line), plus some constant hazard of random failure (green, lower solid line).
In reliability engineering and deterioration modeling, a bathtub curve is a failure rate graph that curves up at both ends, similar in shape to a bathtub. The term can also apply to any graph with this shape.
Many but not all electronic consumer product life cycles follow the bathtub curve. It is difficult to know where a product is along the bathtub curve, or even if the bathtub curve is applicable to a certain product without large numbers of products in use and associated failure rate data.
In reliability engineering, the cumulative distribution function corresponding to a bathtub curve may be analysed using a Weibull chart
See also
- Gompertz–Makeham law of mortality