One of the Eight Quality Principles on which ISO 9000:2000 standards are based is the factual approach to decision making. This Principle states that effective decisions are those based on the analysis of data and information.

In the absence of measurement data, decision making is based on the feelings of managers which are subjective and can differ from one person to another. When there are measurement data, they provide objective evidence on which correct management decisions can be based with little possibility of subjective difference.