Application of Six Sigma on RMC Plant

Six sigma is a quality improvement technique widely used in manufacturing industry. Application of six sigma is yet to be explored exhaustively in the field of construction. This study explores the possibility of application of six sigma in the process of manufacturing of concrete in the RMC plant situated at Navsari, Gujarat. This paper defines and analyzes process performance of RMC plant using six sigma technique. The data was collected in the form of batches and its mix proportion. Total data was collected for 469 batches of the said plant and analyzed using MS Excel. As per IS 4926:2003, tolerance limit for cement, aggregate, and water was set, and batch-wise upper limit and lower limit were calculated. These calculations were then compared with the target value set by the RMC plant. This comparison led to calculate the defects per million opportunity (DPMO) value for the concrete manufacturing process of the RMC plant. With the help of DPMO value, the sigma value is found out to be 1.77 which is not at par with the ultimate sigma level. This work provides valuable insights on the implementation of six sigma technique in the construction industry. Six sigma technique can evaluate the quality of the process and quantify the improvement goals if the process is under performance and less efficient. Improvement in quality of construction can be observed at large extent if six sigma technique is applied to more complicated, volatile, and multistep projects with a linkage to lean principle.