1. A computer system comprising: a processor that processes one or more key performance indicator (KPI) components that define KPI, the KPIs being part of metadata that describes data from which the KPIs are generated, wherein the one or more KPI components are located in a data store that also stores the data from which the KPIs are generated, wherein each KPI includes a plurality of attributes including name, value, status, and trend, as well as expressions for retrieving KPI component data; an expression engine through which a generic application component communicates with the data store to facilitate retrieval and receipt of KPI component data; an inference component of the expression engine to generate and cache KPIs proactively by determining a probability that an expression of a KPI component will be requested and upon determining that the probability exceeds a threshold, automatically generating and caching the KPI from the expression; an intelligent assist component that automatically predicts, suggests, or infers possible attributes to be included in a KPI component and/or performs KPI component adjustments to support defined KPIs; a KPI design component to facilitate definition of one or more KPIs; a linking component that links an extension component that provides additional KPI attributes to an existing KPI component; and the generic application component that extracts and displays data from the data store without a priori knowledge of an actual data schema of the data store, wherein the application component includes an interface to aid retrieval and receipt of KPIs.