Raw material costs account for a major portion of the total manufacturing cost. Thus, reduction of the raw
material cost should be the first step in optimizing the total manufacturing cost. Virgin oil costs approximately 2–3 times more than waste cooking oil indicating that use of virgin oil leads to a substantial increase in total manufacturing cost. As a result, although process I had the lowest cost requirement for building a biodiesel plant, it had a high manufacturing cost offsetting any economic advantage in terms of return on investment or biodiesel break-even price.