A method of transferring a multi-variate process control model from one RF-powered plasma processing chamber (the reference chamber) to another nominally identical RF-powered plasma processing chamber (the target chamber) comprises first determining a multi-variate process control model on the reference tool based upon sensor data, 100. Then, a set of sensor data is taken for the reference chamber by running a designed experiment, 102, and a corresponding set of sensor data is taken for the target chamber using the same designed experiment, 104. The relationship between the reference and target chambers is determined by comparing the results of the designed experiments and calculating a transform matrix representing differences between the two chambers, 106. Finally, the process control model is transformed from the reference chamber to the target chamber using the transform matrix thus obtained, 108.