Bathtubkäyrä

Bathtubkäyrä is a Finnish term that translates to "bathtub curve." It describes a graphical representation of the failure rate of a product or system over its lifespan. The shape of the curve resembles a bathtub, with three distinct phases.

The first phase, known as infant mortality, is characterized by a high failure rate that decreases rapidly. This is often due to manufacturing defects, improper installation, or early design flaws. Once these initial issues are resolved, the system enters a stable period.

The second phase, or useful life, exhibits a relatively constant and low failure rate. During this period, the product or system is operating as expected, and failures are typically random and unpredictable.

The third phase, known as wear-out, sees a gradual increase in the failure rate. This occurs as components begin to age, degrade, and experience mechanical stress. Eventually, the failure rate becomes high enough that the product or system is no longer reliable.

The bathtub curve is a valuable tool for engineers and product designers to understand and predict potential failure modes, allowing for the implementation of appropriate testing, maintenance, and replacement strategies throughout the product's life cycle.