1. A machine-implemented method of investigating one or more business processes each involving a respective set of one or more activities each defined by a respective service and performed by a respective set of one or more resources, the method comprising: providing an interface that enables a user to (i) select a process entity from any of one or more of the business processes, one or more of the services, and one or more of the resources, (ii) select a statistic from a set of multiple statistics, and (iii) select a perspective derived from one or more attribute dimensions of the user-selected process entity; querying a business process data warehouse comprising records derived from process execution data generated during execution of one or more instantiations of the one or more business processes, wherein the querying comprises deriving the user-selected statistic from ones of the records comprising data relating to the user-selected process entity and the user-selected perspective; and on a display visualizing the user-selected statistic presented across the user-selected perspective; wherein the interface enables the user to define the perspective in terms of a taxonomy comprising multiple categories each of which defines a respective Boolean condition on the records of the business process data warehouse, the interface enables the user to (i) label the taxonomy, (ii) label each of the categories, and (iii) specify each of the conditions on the records, and the querying comprises classifying ones of the records of the business process data warehouse into the categories of the taxonomy based on the respective Boolean conditions.