144 Measuring Organizational Leanness Using Fuzzy Approach Seyed Mahmod Zanjirchi, Hossein Sayyadi Tooranlo and Leili Zeidabadi Nejad Economics, Management and Accounting Faculty Yazd University, Iran Abstract To develop a methodology for measuring leanness degree in manufacturing companies using fuzzy logic. Design/methodology/approach- evaluation methods based on human perceptions; make this kind of measuring unreliable. Considering the deficiency, this research develop an approach based on linguistic variables and fuzzy numbers for measuring organizational leanness, and finally use the method for measuring a manufacturing organization`s leanness. The method developed is usable simply by practitioners and make more precise approximate for leanness and then better improvement path for them. Using this method help practitioners to evaluate leanness more precise than other methods presented by now and develop applied solutions to move toward organizational leanness effectively. This is a new method based on fuzzy logic for measuring organizational leanness using human perceptions. Keywords Lean production, Lean indexes, Measuring, Fuzzy logic. 1. Introduction One of the widest spread assertions about production is ending period of mass production era and substitution of novel forms like flexible allocation instead. Waste management or lean production is a new phase of production, take mass and craft production benefits altogether. This method is based on multi-skill workers as well as automatic and flexible machines. In this method we try to reduce production space, investment on tools, engineering work time, and stagnant inventory to half and make our attention to zero defects and zero inventory. In the lean production method, producers desire in reducing resource consumption. In this method, work force, capital invested in machinery purchasing and installation, space required for production, in progress products, materials, and products’ inventories and engineering and design personnel are reduced to half. Therefore, designing and building preiod as well as distribution and selling of a product would be halved, and this is just the main goal of lean production (Womack et al. 1990). After lean production introduction in 1970s, many books and articles have been published regarding various aspects of leanness which show the effect of this paradigm on the world of production and operations. orienting management research toward lean concepts, lot of attempts devoted to development of a tool to measure organizational leanness, since in order to have any kind of analysis, planning and then control (that from main elements of management), having a well-founded and structured style for evaluation of concepts is inevitable (Sink and Tuttle, 1989). In this regard, various styles are proposed by researchers for measuring organizational leanness, like methods according to logical concept of hierarchal process which are developed for organizations’ comparison from view point of leanness (Agarwal et al., 2006). In this process, Pairwise comparisons are used to assess organizations’ leanness capability. However, most researches use integrated index for measuring organizational leanness, that is sum of simple or weighted items’ scores (Kojima and Kaplinsky, 2004; Rivera and Chen, 2007; Shah and Ward, 2007). Cited methods are simple and comprehensible, but since occasionally some of the lean indexes are ambiguous and have unclear definition, and in some cases there is no enough evidence for assessment, or even experts do not have enough ability to assess the indexes meaningfully, ambiguity and vagueness is hidden in the essence of lean assessment methods. Therefore, using indexes to score lean capabilities has two limitations: 1. These techniques do not take in to account ambiguity and multiple probabilities related to the one person`s perception and judgment about a number. 2. Estimator`s choice, preferences and Subjective judgments have prominent effect on these methods. Therefore, using fuzzy logic and linguistic variables, may render a more exact assessment about the degree of organizations’ leanness (Karwowski and Mital, 1986). Many of lean scales, when encounter with ambiguities and multiple probabilities, are explained subjectively by linguistic variables. By using fuzzy concepts, estimators can use linguistic variables as common lexical words and in order to assess the indexes and then link each linguistic variables to a fuzzy membership function. Since fuzzy logic do not impose any assumptions about independence, integrity, or monopoly of evidences, it makes it possible to use ambiguous boundaries in the definitions (Machacha and Proceedings of the 2010 International Conference on Industrial Engineering and Operations Management Dhaka, Bangladesh, January 9 – 10, 2010