Abstract :
Lean manufacturing is absolutely required for distinct industries to create a competitive industrial standard. Therefore, Lean manufacturing became a standard manufacturing mode of the 21st century. Lean manufacturing could have various corresponding synonyms for example lean management and Lean production. It implicates techniques and tools to minimize non value-added activities from the customer point of view. Waste (Muda) is a serious problem in the industry; it creates non value-added services and poor quality of the product. Waste has seven types which can totally or individually occur in the industry that are transport, inventory, motion, waiting, over-production, over-processing, and defect. Using lean tools and techniques all several wastes can be eliminated. Hence implementing the lean manufacturing system is becoming a core competency for any type of organization to sustain. This paper aims to conduct a quick review of Lean principles, the most commonly used Lean techniques, and Lean assessment. In order to obtain the goals of this work, the previous literature has been examined and the most important lean tools applied in the process of conversion to lean in companies and lean assessment have been also identified. This investigation elaborates that there is an obvious difference in the assessment methodologies according to many factors including the size of the companies, type of companies and the main objective of the assessment.