Maintainability

In engineering, maintainability is the ease with which a product can be maintained in order to: In some cases, maintainability involves a system of continuous improvement - learning from the past in order to improve the ability to maintain systems, or improve reliability of systems based on maintenance experience.
 * correct defects or their cause,
 * repair or replace faulty or worn-out components without having to replace still working parts,
 * prevent unexpected working conditions,
 * maximize a product's useful life,
 * maximize efficiency, reliability, and safety,
 * meet new requirements,
 * make future maintenance easier, or
 * cope with a changed environment.