1. A method for multivariate analysis using a mathematical model for generating model data and actual data for more than one variable, wherein the model data is substantially representative of more than one variable, said method comprising: for each variable, determining a difference between the model data stored in a logic module of a machinery monitoring system and the actual data received from machinery being analyzed; for each variable, determining by the logic module a factional impact on performance; for each variable, determining by the logic module a weighted deviation based on the determined difference and the determined factional impact; and transmitting the weighted deviation to an output device.