Lean manufacturing is a world class philosophy and a well-approved strategy for improving quality, productivity and reduce cost to makes the organization more competitive in the changing global markets, where every organization pursues continuously to improve their lean performance by reducing or eliminating all types of waste. Fuzzy DEMATEL has been utilizes to develop assessment model to help focusing more on the most influence lean dimensions for driving the improvement process. Five essential lean dimensions have been studied that extracted by a survey to assess degree of relation, importance, and category the lean dimensions and determine the interrelationships among them. The assessment model has been developed using MICROSOFT EXCEL and applied by surveying five companies for soft drink and healthy water by a questionnaire to get their opinion about importance and the influence each lean dimension on another. Interrelationship diagram show top management has highest effect on all lean dimensions so it is considered as driving lean dimension.