A solution is introduced in which, instead of providing an object with all information, some of the information is provided by means of one or more group definitions. This is achieved by performing a grouping operation during which an object having object data defining at least one property of the object is assigned to a group having at least one group definition defining at least one feature shared by objects assigned to the group; and storing as mapping information a grouping time indicating the time the grouping operation was performed to the object and a link between the object and the group.