A quantitative model to predict the cost of quality nonconformance in the construction industry

Abstract

The use of modern quality management techniques, such as, statistical process control, TQM, QA/QC, the Deming and Taguchi methods, motivation theories, modern training and supervision methods, effective communication systems, etc., to improve quality, productivity, cost reduction, sales/profits and competitiveness in the U.S. construction industry has increased during the last decade as the U.S. construction industry strives to reverse its declining market share. The reversal in the competitive position can be achieved when the industry regains and maintains its lost market share through producing high quality products at less cost. The cost of quality nonconformance has been identified to be a major factor in the loss of competitiveness by the U.S. construction industry. It accounts for about 1.5 percent of the total project cost in regular situations and can cost up to 20 percent in extended circumstances. The concept of quality nonconformance cost in the U.S. construction industry was developed and the elements identified. Existing Quality Management models were reviewed and rejected for use in predicting the cost of quality nonconformance in the construction industry. Fault-tree analysis method was then reviewed and applied to develop a quantitative model for quality nonconformance in construction. The model was calibrated with data obtained from construction industry professionals. The calibration process estimated the probability of loss for each basic event, and the total for a typical project was found to be approximately 7 percent. The validation showed that a close correlation between the predicted and observed quality nonconformance cost values can be achieved with many comparison data.