Cutting betel nut machines are increasingly being designed by engineers using local material. However, the performance of the cutting betel nut machine is influenced by the moisture content of the betel nut and the rotational speed of the machine. In this study, the performance of cutting a betel nut machine under moisture content of betel nut and rotational speed of the machine was studied using response surface methodology (RSM) and desirability function. Central Composite Design (CCD) coupled with RSM and desirability function was employed to evaluate the impact of moisture content of betel nut (34.68–50.54%, w.b.) and rotational speed (600–1000 rpm) on machine capacity (kg/hr), efficiency (%), and losses (%) responses. The desirability function was then used to optimize moisture content and rotational speed yielding maximum machine capacity and efficiency at lower losses. Three verification experiments were run to ensure the empirical relationships were valid. Optimum requirements of process parameters have been seen at which moisture content of 50.54% (w.b.) and rotational speed of 1000 rpm was achieved in maximum machine capacity of 44.16 kg/hr at higher efficiency (92.72%) and lower losses (6.31%). The model's conclusions were very consistent with the confirmed values. The results proved that an appropriate performance of the machine can be achieved using moisture content of betel nut and rotational speed of machine cutting betel nut.

Productivity improvement plays essential role on cost reduction and production planning in many organizations. There are literally various methods for measuring productivity and improving systems’ capabilities such as total quality management, 5S, etc. In this paper, we perform an empirical investigation to find out whether implementing 5S could reduce interruptions in production systems in one of pipe and profile manufacturing units located in province of Semnan, Iran. The proposed study compares the mean and standard deviations of waste materials before and after the implementation of 5-S in three different lines and statistical tests indicate that 5-S have made the necessary change on production planning and it could reduce waste materials, significantly.