Indexes - a single number calculated from a set of prices or of quantities. (Source: http://en.wikipedia.org/wiki/Index_%28economics%29)

Quality management - is a method for ensuring that all the activities necessary to design, develop and implement a product or service are effective and efficient with respect to the system and its performance.
(Source: http://en.wikipedia.org/wiki/Quality_management)

Metric - A metric is a standard unit of measure, such as mile or second, or more generally, part of a system of parameters, or systems of measurement, or a set of ways of quantitatively and periodically measuring, assessing, controlling or selecting a person, process, event, or institution, along with the procedures to carry out measurements and the procedures for the interpretation of the assessment in the light of previous or comparable assessments.
(Source: http://en.wikipedia.org/wiki/Metrics)