Stepwise Kaizen Parameters Improvement via the Path of Steepest Ascent

Kaizen has been widely accepted as a continuous process improvement with the gradualist approach. This paper presents research carried out to explore a pattern of an investment in Kaizen to enhance overall profit. System dynamics-based simulation has been employed with an optimization technique, a Steepest Ascent approach, to improve experimental variables e.g. the amount of spending on prevention and appraisal activities, the time and the amount to reduce the investment which results in maximum Net Present Value (NPV) of profit. The simulation model in this study is based on a Thai automobile manufacturer as a case study company. The result suggests that the investment in Kaizen should be reduced economically when the process is under controlled. It can be named as the 'Stepwise Kaizen', which was proved in this study that it provides greater overall profit than the constant spending. This study also presents the behavior of quality costs and profit against time scale along the Stepwise Kaizen implementation.