[Show abstract][Hide abstract] ABSTRACT: Purpose – The purpose of this paper is to explore concrete design methodology which can improve production technology. Design/methodology/approach – An application of advanced process control (APC) on distributed control systems (DCS) was designed by defining the project target, scope, and control strategy. Calculation is based on heat and mass conservation, such as RPID=FC 203×900×(DC 241 PV-400)×1.06/500 DC 241 PV; CATRATE=LEVELRATE×0.22×3.14/4. The quality controller writes the control target on the density controller, which writes the initial value or output value onto the DCS. Findings – The technique has dramatically increased the control quality of the DCS system: production capacity of the equipment has been improved and the aim of fecundity with little input is realized. The transit time of the product name is shortened and the excess stock is reduced. Originality/value – The paper is aimed at operational researches and engineers.