Which term describes the ability of a product to maintain functionality over time?

The correct term that describes the ability of a product to maintain functionality over time is durability. Durability refers specifically to how well a product can withstand wear, pressure, or damage, which affects its longevity and usefulness. A durable product is built to last and continue functioning effectively over an extended period, even under normal usage conditions.

Reliability, on the other hand, refers to the consistency of a product’s performance—meaning it can be expected to operate without failure over a specific period or under certain conditions. Although it’s closely related to durability, reliability focuses more on the likelihood that the product will perform its intended function consistently rather than the physical ability to withstand degradation from use over time.

Usability pertains to how easy and intuitive a product is for users to operate, while scalability refers to the ability of a product or system to handle a growing amount of work or to be enlarged, which is not relevant to the context of maintaining functionality over time.