1. A system for monitoring and diagnosing on-line multivariate process variable data in a process plant, wherein the multivariate process data comprises a plurality of process variables each having a plurality of observations, the system comprising: a data collection tool adapted to collect on-line process data from a process control system within the process plant when the process is on-line, wherein the collected on-line process data comprises a plurality of observations of a plurality of process variables; an analysis tool comprising a multivariate statistical analysis engine adapted to represent the operation of the process based on a set of collected on-line process data comprising a measure of the operation of the process when the process is on-line, wherein the representation of the operation of the process is adapted to be executed to generate a result, and wherein the analysis tool is adapted to store the representation of the operation of the process and the set of collected on-line process data; and a monitoring tool adapted to generate an output based on a parameter of the representation of the operation of the process, wherein the parameter of the representation of the operation of the process comprises one or more of a result generated by the representation of the operation of the process, a process variable used to generate the representation of the operation of the process and the set of collected on-line process data.