AN EMPIRICAL STUDY OF THE SIX SIGMA APPROACH FOR REDUCING THE NUMBER OF COBBLES - STATISTICAL SOFTWARE QUALITY ASSURANCE TECHNIQUE

The blooms of size 250*320sqmm size which are being produced at steel melt shop are kept at bloom storage yard. Accordingly, these blooms are charged into the furnaces and rolled into the billets of size 125*125sqmm. The bloom is converted into billets when drawn through seven stands of variable speeds. Later the billet is passed through the shear to get cut into three pieces for passing to the Wire Rod Mill (WRM) feeding. The material passing from stand-1 is continuous and passes through the stand-7 where it gets the cross section of 125*125sqmm. whenever a problem arises due power failure or any other malfunctioning; the material struck up and is twisted in between the stands which is known as COBBLE. Removing the cobble takes minimum three to four hours which hampers the production and is a direct loss to the company. Thus the problem needs to be looked into and the solution aroused in the form of Six Sigma tools. Six Sigma is widely recognized as a business that employs statistical and non-statistical tools and techniques, change management tools, project management skills, team work skills and a powerful roadmap (DMAIC) to maximize an organization’s return on investment (ROI) through the elimination of defects in processes. DMAIC methodology provides with a data-driven methodology for achieving sustained process improvements by reducing defects. This methodology is used to identify inadequacies in the existing process and to make lasting and controllable changes to products and processes that improve product quality, customer satisfaction and the company’s profitability. Thus, with the help of proper tools and techniques of this procedure the problem had been handled. Sufficient data was collected and the various factors that affect the process and lead to failure were analyzed. The Six Sigma roadmap enabled to identify the potential causes of the failure and provided effective methods to eliminate them or minimize them. The project is all about the way the problem was tackled and the process was improved.