The objectives set provide a basis for measurement. In addition there may be other measurements adopted by management to help in showing how well a process works and to assist in helping to attain objectives set. Above all the measurements adopted should be useful to the company by providing information that can be acted on.
Once measurements have been made the data is analysed to see what can be learnt. Analysis can show whether or not a process is working as planned. It can also identify best practice that can be adopted elsewhere in the organisation.
ISO9001 also requires on of the measurements to be regarding customer satisfaction.