TO CONTROL OF THE CHEMICAL PROCESSES, THE SELECTION AND CORRECT SETTING OF THE INPUT VARIABLES ARE IMPORTANT. BUT FIRST, THE RELATIONSHIP BETWEEN INPUT AND OUTPUT VARIABLES MUST BE DETERMINED. THE SERIES OF TECHNIQUES USED IN THE EMPIRICAL STUDY OF THE ASSOCIATION BETWEEN response VARIABLES AND SEVERAL INPUT VARIABLES IS CALLED response SURFACE METHODOLOGY (RSM) [1]. MUCH OF THE EMPHASIS IN RSM HAS BEEN ON BUILDING MODELS FOR ONE response, WHEREAS CHEMICAL PROCESSES OFTEN HAVE MANY responseS, THE VALUES OF WHICH IDEALLY REQUIRE SIMULTANEOUS optimization [2]. A STRATEGY FREQUENTLY USED CONSISTS OF CONVERTING THE MultiPLE responseS INTO A SINGLE response (A COMPOSITE FUNCTION) FOLLOWED BY ITS optimization. THE COMPOSITE FUNCTION IS USUALLY DEFINED AS A DESIRABILITY FUNCTION. IN THE MOST POPULAR DESIRABILITY FUNCTION-BASED METHOD, THE SO-CALLED DERRINGER AND SUICH’S METHOD [3], ANALYST NEEDS TO SPECIFY VALUES TO FOUR TYPES OF SHAPE PARAMETERS/WEIGHTS. THIS IS NOT A SIMPLE TASK AND HAS IMPACT ON THE METHOD’S SOLUTION. RECENTLY N. COSTA ET.AL PROPOSED A NEW DESIRABILITY FUNCTION METHOD [4] THAT IS EASY TO UNDERSTAND AND IMPLEMENT BY PRACTITIONERS, INTERACTIVE AND REQUIRES A NUMBER OF WEIGHTS JUST EQUAL TO THE NUMBER OF responseS AND EXPLICITLY CONSIDERS THE response SPECIFICATIONS. HOWEVER, THIS APPROACH DOES NOT CONSIDER THE VARIANCE-COVARIANCE STRUCTURE OF THE responseS. IGNORING SUCH INFORMATION MAY LEAD TO AN UNREALISTIC SOLUTION IF, IN FACT, THE responseS HAVE SIGNIFICANTLY DIFFERENT VARIANCE LEVELS OR ARE HIGHLY CORRELATED [5]. THE MAJOR ADVANTAGE OF THE LOSS FUNCTION APPROACH IS ITS ABILITY TO INCORPORATE THE VARIANCE-COVARIANCE STRUCTURE OF THE responseS AS WELL AS THE PROCESS ECONOMICS THAT FOCUSES ON THE LOSS FUNCTION APPROACH, WHICH USES A MEASURE BASED ON A SQUARED ERROR LOSS FUNCTION.IN THIS LECTURE SOME NEW METHODS THOSE HAVE BEEN PROPOSED TO optimization OF CHEMICAL PROCESSES ARE DISCUSSED. IT IS FOCUSED ON BOTH DESIRABILITY FUNCTION METHOD AND THE LOSS FUNCTION APPROACH. ALSO THESE TWO METHODS ARE COMPARED TO EACH OTHER.