1. Process for modelling an information system, in order to measure performance and monitor service quality for this information system, said process including object-oriented modelling of said information system, each element of said information system being represented by an Instance, wherein: data relating to a first Instance are collected on said first Instance or on one or several other Instances, said collected data are attached to said first Instance via said object-oriented modelling of the information system, classes of objects of the information system, called Vistas, are defined, each Vista comprising Properties and/or Indicators, the instances of the information system belonging to one or several from said Vistas, characterized in that said process further comprises rules defining inheritances between different Vistas, and different models of the information system is definable from a same set of Vistas via different rules.