An Improved Approach to Line Balancing for Garment Manufacturing
Production managers in the apparel industry frequently face the issue of being unable to complete the orders at the scheduled time. One of the reasons for this issue is the unavailability of a Line Balancing procedure that could encompass the stochastic nature of the sewing process, which is manifested through the likes of variability of sewing times, machine breakdowns, correcting defective products, and operator breakings such as for changing bobbins and drinking water. The objective of this research is to introduce a diverse approach to Line Balancing through giving due consideration to the stochastic nature of the process. The improved approach was developed through case study approach. Having selected a sewing line in an apparel factory, the process times of operations, major random events and the times elapsed between random events were recorded. Then the whole production cycle was simulated using ARENA software. By attempting and analysing different scenarios, a different approach for line balancing was introduced. The initial steps of the algorithm developed includes: collecting processing times and necessary information on manufacturing process, fitting standard probability distributions to both value added and non-value added activities, developing the precedence diagram, developing an initial algorithm for balancing a production line and finally, making necessary adjustments to the algorithm analyzing different scenarios. In order to check the validity of the algorithm, a production line was balanced for two different daily production targets. Thus, the application of proposed algorithm to balance the production line reduces the gap between the expected production target and the real achievement.