Process variability and its effect on plant performance

This report presents the preliminary findings of a research study to determine the factors which enable a manufacturing plant to simultaneously achieve high labour productivity, fast, reliable delivery and high quality consistency. The conclusions are based on analysis of a database containing details of 953 manufacturing plants in the UK. Based on the performance measures mentioned above, a composite performance measure was calculated for each plant in the database. The plants were then divided into groups of high performers, medium performers and low performers. Using statistical analysis, those differences between the high and low-performing plants that were significant were identified. The main factors differentiating high-performing plants from the rest were those associated with low process variability, high schedule stability and more reliable deliveries by suppliers.