Performance evaluation through simulation modeling in a cotton spinning system

Spinning system is an important segment in the textile industries, which consists of a set of processes to convert raw cotton into yarn. This spinning process can run continuously only when there are no breaks in the output of yarn produced from every spindle. However, the yarn does break due to several reasons like ambient conditions in the spinning facility, such as humidity, quality of cotton and spindle speed, etc., and other factors such as piecing (joining) of the broken yarn, using a pre-determined yarn length, by a operator called ‘sider’. Breaks in yarn spinning cause a decrease in productivity. The random nature of yarn breaks, in addition to the variations in spinning process parameters also influence frequency of their occurrence and ultimately the downtime of the spindle as the broken yarn waits in a queue to be pieced. Normally a sider is responsible for a group of six adjacent spinning frames. This man–machine system (sider-spinning frame system) is modeled and analyzed in this paper using graphical simulation software package. Applying the real data collected from a cotton-spinning mill, a simulation model has been developed and validated. This validated model is used for evaluating alternate routings available for the sider to find out the optimum route.