An integrated metric to measure, track and manage leanness in manufacturing systems

Many industries have focused on lean transformation rather than measuring their leanness level. Failing to measure and track the lean level of the system will adversely affect that transformation effort. This research presents a new integrated metric that can be used to measure system leanness as well as track and direct leanness activities. System efficiency, flow type and overall variability are integrated into the proposed Efficiency Flow Variability (EFV) leanness metric. The mathematical foundation which captures each of the three parameters of the proposed metric is firstly presented. The new metric is then analyzed through what is called performance zones. Different manufacturing scenarios were presented based on these zones to assess multiple manufacturing lean management approaches. The developed integrated metric is then demonstrated via a case study of a steel pipe facility. The demonstration was based on assessing the lean level of the facility and based on the assessment, different lean management policies were suggested to improve the system's performance. Results show the developed metric can be successfully used to measure the leanness level of manufacturing systems and offers various guidelines to better implement and manage lean systems. Some suggestions and recommendations are provided regarding the efficiency, flow type and variability.