Table 2.
Definitions of key terms used in this paper.
| Term | Definition |
|---|---|
| Durability | Ability to function as required, under defined conditions of use, maintenance and repair, until a limiting state is reached |
| Functional lifetime | Time a product is used until the requirements of the user are no longer met, due to the economics of operation, maintenance and repair or obsolescence |
| Limiting event | Occurrence, which results in a primary or secondary function no longer being delivered |
| Limiting state | Condition after one or more limiting event(s) |
| Reliability | Probability that a product functions as required under given conditions, including maintenance, for a given duration without limiting event |
| Repair | Process of returning a faulty product to a condition where it can fulfil its intended use |
| Reuse | Process by which a product or its parts, having reached the end of their first use, are used for the same purpose for which they were conceived |
| Technical lifetime | Time span or number of usage cycles for which a product is considered to function as required, under defined conditions of use, until a failure occurs |
| Technical withstand (or resistance) | Capability to withstand stresses such as, for example, electrical, mechanical and environmental stresses |
| Upgrade | Process of enhancing the functionality, performance, capacity or aesthetic of a product |