Patent ID: 7917240

Claim:
A method of monitoring multivariate process data in a process plant, wherein the multivariate process data comprises a plurality of process variables each having a plurality of observations, wherein at least one process variable comprises an unknown process variable control limit, the method comprising: collecting a set of data for the at least one process variable, wherein the set of collected process variable data is representative of a normal operation of the process when the process is operating normally and comprises a plurality of observations of the at least one multivariate process variable; determining the unknown process variable control limit under the normal operation of the process; defining each process variable as a process variable vector comprising a set of observation components, wherein the set of observation components comprises time dependent process data corresponding to the observations of the process variable; normalizing each of a plurality of process variable vector transformations to the same process variable control limit using a scaling parameter unique to each process variable to generate a common process variable control limit for the process variables, wherein each process variable vector transformation is a function of a univariate variable unifying the process variables; calculating a multivariable transformation as a function of the plurality of process variable vector transformations each corresponding to one of the process variables; and representing an operation of a process based on the multivariable transformation, wherein the representation of the operation of the process designates a multivariate projection of the process data by the univariate variable for each of the process variables, wherein representing the operation of the process based on the multivariable transformation comprises monitoring each process variable in relation to the determined process variable limit.