What Is Bathtub Curve?

When it comes to bathtubs, everyone loves taking a soak. But when it comes to technology, the bathtub curve can be a little less fun. The bathtub curve shows how many units might fail during any given phase of a three-part timeline. The first downward portion of the curve is called an "infant mortality" phase and shows how several units would quickly fail due to defects or other issues. The second part of the curve is the "normal lifetime" or "useful lifetime" segment with a low failure rate. The third part is an end-of-life increasing failure rate. Together, these three segments look like a bathtub with two steep edges and a flat bottom. An example of the bathtub curve would be a new car on a dealer's lot. At first, the vehicles are brand new, so there will be a high failure rate due to manufacturing defects, but that rate will decrease as the car age. As the cars approach their third year and useful lifetime, there will be a low rate of failure as they naturally age and wear out. At the end of their useful lifetime, the cars will have a higher loss rate as they break down and are scrapped. Another function of the bathtub curve is to represent the likelihood that a successful initial launch of a product will lead to future problems. A product's initial success will increase usage and adoption, which may lead to an accelerated rate of failure. Companies may monitor usage or track certain use aspects to predict when products enter the second infant mortality phase. Hey, it's the bathtub curve. The bathtub curve is a model that shows how likely your product or technology is to fail at different stages of its life. It has three parts; the first is called "infant mortality," showing how many units might fail immediately because of defects or other issues. The second part is called "normal lifetime" or "useful lifetime," with a low failure rate. The third part, called "end-of-life," has an increasing failure rate.