2.3. Pre-process
It needs to identify and calculate the feasibility study from economic aspects before
investing, such as, identifying the assumptions, investment cost, operational cost comprising
fixed and variable costs. The first process is to create fuzzification value in input variables for
biodiesel price, waste cooking oil price and interest rate by using Triangular Fuzzy Number
(TFN) [20]. Feasibility of this study is assessed based on four criteria as follows.