Process improvement and efficiency analysis using the Single-Minute Exchange of Dies method applied to the set-up and operation of screen-printing machines

Lean manufacturing methods are concerned with simplifying the production process and thus maximising efficiency and minimising wastage. All production processes contain several steps, which include sub-steps such as cleaning and changing devices and preparing the production areas for later steps. Most of these sub-steps require that machines are stopped and therefore they must be performed as quickly as possible. This downtime causes a decrease in efficiency, while increasing the costs and production time. Single-Minute Exchange of Dies (SMED) is a lean manufacturing strategy that has been applied successfully in many sectors to minimise excessive downtime. In this study, the SMED technique is applied in a textile screen-printing company for the case of changing the screens between each design. The steps are evaluated and designated as either external steps, which are performed without downtime, or internal steps, which take place during downtime. The number of external steps is increased while being decreased for internal steps. Also, the production time decreased by 54% and a 32% increase in efficiency was achieved during the screen-printing production of a sample t-shirt.