I guess you are refering to the Key Performance Indicators (KPIs) which are the measurement that you use to know if a process is performing as it was expected. To successfully determine your KPIs you need to define which are the most important elements of your QMS processes. Once you have determined the KPIS, then you will need monitor and measure them, analyze and evaluate the results, and finally use this as a method to control and improve your Quality Management System.
Of course you need to make sure the KPIs are measurable. For instance, if you are measuring an assembly process by how many non-conforming assemblies are made your KPI could be percentage of conformance product finished. This can be monitored to ensure that your process is being conducted as expected, with a goal of 98% good product.
To learn more about key performance indicators, see these materials: