Lean principles, aiming at eliminating waste and increasing efficiency at a company, take their roots from the initiatives of Taiichi Ohno. After the implementation of the principles at the Toyota Motor Company for the first time, businesses started to discover the benefits of lean implementation in terms of efficiency increase. As the adaptation of lean into the manufacturing sector is continuing, the necessity of assessing the level of leanness at the firm-level maintains its importance. Taking systems approach as a basis, the lean performance of an organization should be assessed as a whole. Therefore, we propose a holistic leanness assessment framework, which encapsulates various dimensions of the leanness assessment and we identify the importance and causal relationships between the sub-criteria. In order to identify the importance and causal relationships between the sub-criteria, we used fuzzy Decision Making Trial and Evaluation Laboratory (DEMATEL). Our findings show that the most influencing factor in the cause group is ‘technology and product design’ which indicates the companies’ necessity to focus on Industry 4.0 during their operations. The results also illustrate that the most influenced factor in the effect group is ‘productivity’, in which companies can investigate strategic competitive advantages. The design of a holistic framework and the implementation of fuzzy DEMATEL offers a way to identify the importance and the causal relationships between the sub-criteria. With the help of a case study conducted in the plastics industry of Turkey, we offer managerial implications that could help managers to implement the proposed structural leanness assessment framework. KeywordsLeanness, Lean manufacturing, Leanness assessment, Fuzzy logic, Fuzzy DEMATEL, Performance assessment.

中文翻译：

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整体性评估的全新概念框架

精益原则旨在消除公司的浪费并提高效率，其根源于大野泰一的倡议。首次在丰田汽车公司实施该原则后，企业开始发现精益实施对提高效率的好处。随着精益向制造业的适应不断，在公司一级评估精益水平的必要性仍然很重要。以系统方法为基础，应从整体上评估组织的精益绩效。因此，我们提出了一个整体的瘦度评估框架，该框架封装了瘦度评估的各个维度，并确定了子标准之间的重要性和因果关系。为了确定子标准之间的重要性和因果关系，我们使用了模糊决策试验和评估实验室（DEMATEL）。我们的调查结果表明，造成这一原因的最主要因素是“技术和产品设计”，这表明公司在运营过程中必须专注于工业4.0。结果还表明，影响组中影响最大的因素是“生产力”，企业可以在其中调查战略竞争优势。整体框架的设计和模糊DEMATEL的实现提供了一种方法来确定子标准之间的重要性和因果关系。借助土耳其塑料行业的案例研究，我们提供了对管理的启示，可以帮助管理人员实施建议的结构精益评估框架。关键字：精益，精益制造，精益评估，模糊逻辑，模糊DEMATEL，绩效评估。