The objectives of this study research were to reduce the production costs by reducing the amount of scrap from the plastic ejecting process and to study the suitable mixture ratio of plastic and scrap and the temperature for plastic ejecting process (final-end) that would affect the mechanical properties of the impact test. From the problems found in this case study and for which they represented a major impact upon the costs of manufacturing process, can be verified that there were losses due to the inappropriate controls of plastic molding process that generate excessive amount of scrap approximately 8.7% of the total production volume. In order to solve these problems, the researcher has suggested the approaches to decrease the amount of the scrap as follows;
1) The fishbone chart has been employed to analyze the causes and impacts in order to initially solve the problems.
2) Experiment with the design of 2k Factorial in order to study the mixture and temperature for plastic molding (the final end) that has affected the mechanical attribute of the collision force in order to meet the requirements set by the clients.