5 Types of Design Life

John Spacey, updated on May 28, 2017

Design life is the forecast life expectancy of buildings, infrastructure, facilities, equipment and products. As the term suggests, design life is estimated by designers such as engineers or architects based on expected uses and the properties of the design, materials and parts. The following are common categories of design life.

Long-lived Designs

Durability is often a key operational and financial requirement with maximum durability at reasonable cost being the target. For example, if solar panels are financed on a 25 year basis, it is important to customers that they last 25 years.

Fit for Purpose

Durability is often considered with respect to the purpose of an item. For example, things that are intended to be used once such as tissue paper need not be durable.

Safety by Design

Durability is often used to improve safety. For example, the durability of a jet engine is a factor in the safety of an aircraft over time.

Biodegradable

In many cases, durability can be an environmental problem. For example, fishing equipment that is lost at sea contributes to pollution and often poses a threat to wildlife. As such, things may be designed to decompose quickly into food as a sustainability strategy.

Planned Obsolescence

In some cases, firms design things to wear down in order to increase sales. If a razor blade lasts forever, customers won't purchase replacements. Planned obsolescence is highly unpopular with customers. As such, it can backfire as competitors may offer more durable products that customer prefer.

Overview: Design Life
Type	Reliability Engineering
Definition	The life expectancy of buildings, infrastructure, facilities, equipment and products as forecast by designers.
Related Concepts	Reliability Engineering Safety Design Durability Waste Is Food Fit For Purpose