Soft sensors driven by data are very common in modern industry to predict critical variables which are difficult to measure using other variables that are relatively easier to obtain. The use of soft sensors implies some challenges, such as the predictor variables colinearity, the time-varying and possible non-linear nature of the industrial process. To deal with the first challenge, the partial least square (PLS) regression has been employed for many applications to deal with the linear variable relationships, with noisy and highly correlated data. However, the PLS model needs to deal with the other two issues: the non-linear and the time-varying side behaviour of the processes. In this work, a new knowledge based methodology for a recursive non-linear PLS algorithm (RNPLS) is systematized to deal with these issues. Here, the non-linear PLS algorithm is made by carrying out the PLS regression over the augmented matrix of input, which includes knowledge based non-linear transformations of some of the variables. This transformation depends on the type of the system, and takes into account the available knowledge about the process, which is provided by expert knowledge or em-