Abstract:
One of the shortcomings of the conventional single-minute exchange of die (SMED) method is that the improvements are made only upon the machine to reduce setup times. Although most of the setup activities involve operators, they are not considered adequately in this method. In workplaces with non-ergonomic setup systems, operators are exposed to different ergonomic risks, and thus, muscle fatigue is a problem for them. During the setup activities, muscle fatigue increases the setup times and risks of work accidents. In this study, the muscle fatigue assessment (MFA) method, also known as the Sue Rodgers method, was integrated into the conventional SMED method in order to evaluate the ergonomic risks in setup activities. Since the tools of the conventional SMED method are insufficient to shorten setup times, the grey-based Taguchi method, which consists of multiresponses such as setup time and fatigue risk, has been used for a setup activity. This method allows the determination of the process factor levels to minimize these responses. A form has also been developed for the integrated SMED method, which is called the Setup Observation and Analysis Form. The developed integrated SMED method based on the Sue Rodgers muscle fatigue assessment method and grey-based Taguchi method has been applied to a CNNx machine in a factory producing aluminum profiles. The overall setup time has been reduced to 73.5 min from 196 min, which indicates a total of 122.5 min and 62.5% improvement. With the conventional SMED method, the setup time is reduced to 101 min, whereas with the new approach, the setup time is reduced further to 21.5 min.
