An application of six sigma methodology to reduce lot-to-lot shade variation of linen fabrics

There was a problem of shade variation of dyed fabrics in a reputed textile company leading to the increase in process cycle time due to the extra amount of color addition or stripping. The extent of reprocessing fabrics was estimated to be around 75%. The objective of this work was to reduce the shade matching time in the fabric dyeing process by optimizing the effect of the controllable parameters. The problem was tackled using the DMAIC cycle of disciplined Six Sigma methodology. Initially, the process baseline sigma level was found as 0.81 and a target sigma level was set at 1.76. The outcome of the analyses observed at every phase was explained based on textile technology. Actions taken on the critical activities led to the reduction in average excess time as 0.0125 h/m. The yield of the overall process has improved to 82% with an improved sigma level of 2.34. The estimated annual saving is to the tune of Rupees eighteen lakhs (over $40,000). The proposed control schemes from this study are already in place.