kestoiän

Kestoiän is a term used in reliability engineering and product labeling to denote the expected service life of a product or component. It refers to the length of time during which the item is expected to operate within defined performance and safety standards under normal use before it reaches a specified failure threshold or becomes unsuitable for use. Kestoiän is influenced by design, materials, manufacturing tolerances, operating environment, and maintenance, and it is typically published or inferred from testing data and historical performance.

Estimation of kestoiän relies on life data gathered through testing and field experience. Methods include accelerated life testing, failure-time analysis, and predictive modeling such as Weibull or exponential distributions. Results are often expressed through metrics like mean time to failure (MTTF), failure rate, or a warranty period. In practice, kestoiän informs warranty terms, maintenance planning, replacement scheduling, and sustainability assessments. It is commonly specified for consumer electronics, appliances, vehicles, and industrial equipment, among other products.

Kestoiän is distinct from shelf life, which concerns the duration a product can be stored without use, and from obsolescence, which reflects changes in relevance or compatibility rather than physical degradation. Reporting may include degradation thresholds, such as a defined percentage drop in performance (for example, lighting equipment specified by a certain lumen output remaining after time) or a specified failure probability by a given date.

Limitations exist: kestoiän is an estimate based on models and representative usage; real-world results vary with environment, misuse, maintenance, and usage patterns.