Application of green-modified value stream mapping to integrate and implement lean and green practices: A case study

Manufacturing companies are striving for more environment-friendly operations and products, creating an increased need for a balance between environment friendliness and efficiency gains. This can be done by integrating and implementing lean and green practices simultaneously. To attain this objective, this paper presents a green-modified value stream mapping model, which uses carbon efficiency and carbon emission as evaluation indicators. The model identifies the integrating level of time flow, energy flow, material flow, and transportation flow at each phase of the production process from the perspective of seven wastes and converts them into carbon emission flow. The proposed framework can visualise and assess the manufacturing process performance and help overcome the challenges associated with integrating and implementing lean and green practices. In addition, a mathematical model of carbon efficiency is established to analyse and calculate carbon emission flow of all types of wastes to identify opportunities for improvements in eliminating wastes. The effectiveness of this method is demonstrated with a case study of a manufacturing unit producing metal stamped parts. Further studies are required to test the proposed framework under various fields including other manufacturing fields to improve the practical validity and expand the application scope.