Measuring External Product Attributes ◾ 461
e ISO/IEC 25010 standard denes maintainability as follows:
Maintainability is the degree of eectiveness and eciency with
which a product or system can be modied by the intended
maintainers.
ISO/IEC 25010 2011
We noted in Chapter 5 that maintenance involves several types of
changes. e change may be corrective, in that it is correcting a fault that
has been discovered in one of the soware products. us, corrective main-
tenance involves nding and xing faults. Or the change may be adap-
tive: the system changes in some way (the hardware is changed, or some
part of the soware is upgraded), and a given product must be adapted to
preserve functionality and performance. Implementing these cha ...