1. A method of configuring key performance indicators (KPIs) for monitoring and testing a network, comprising the steps of: defining a set of event rules for generating one or more key performance indicator (KPI) events based on one or more events; defining a set of aggregation rules for aggregating the one or more KPI events based on a time period; monitoring, by one or more computers, a plurality of events generated by one or more devices in the network and received by the one or more computers; matching, by the one or more computers, an event from the plurality of events with the set of event rules; generating, by the one or more computers, a KPI event based on the event and the set of event rules; and forming, by the one or more computers, a multi-dimensional KPI value by combining the KPI event with other KPI events generated over the time period based at least in part on applying numeric aggregation operations defined by the set of aggregation rules, the multi-dimensional KPI value indicative of a performance of the network with respect to a plurality of dimensions including at least a customer dimension and a service provider dimension, wherein the set of event rules or the set of aggregation rules is dynamically updated based on user input describing one or more KPIs of interest.