The purpose of this thesis is to investigate which practices lean enterprises adopt to focus on value streams. An exploratory case study of four plants is developed. The four plants have successfully performed a lean transformation with significant performance improvements, and belong respectively to Delphi Diesel Systems, Sogefi Filtration, a company within the furniture industry and Renault. The organizational practices associated with value stream focus identified are: (1) the establishment of organizational units based on value streams; (2) the use of a performance measurement system based on value streams, and (3) the adoption of a formal meeting system. These organizational practices were found in all four of the studied companies. The adoption of these practices was standard and consistent across the different organizational units within the studied plants. However, the application of the concepts strongly depended on the specific circumstances of the plants such as size, complexity and lean transformation maturity. This exploratory research provides a contribution in the fields of organizational practices involved in the transition to lean enterprise. Managerial implications consist of the possible application of the described practices to other cases and situations.Keywords-Value stream, lean, performance measurement, meeting system, focus 8 9 AcknowledgementsAlthough my name is the only author name on the front page, this is by no means an individual effort. There are many people who have taken part in producing this thesis.First of all I would like to thank my Supervisor, Dr. Jordi Olivella for tirelessly supporting and encouraging this work. Dr. Olivella has had a major influence on this thesis through valuable discussions and support. Dr.Olivella taught me what research is all about. Jordi has proven that it is possible to play the role of both a serious supervisor and a friend. 1-INTRODUCTIONThis chapter starts with describing the background of the thesis. Afterwards the overall aim of the thesis, objectives and purpose are presented to the reader. The structure of the thesis is given as the last part of this chapter. 26 IntroductionLean management strategy has been widely adopted by manufacturing companies. It is broadly used, in particular, by the automobile industry to achieve high performance standards . A consequence of the decision to adopt lean management is the use of the tools and the implementation of the practices. A deeper adoption requires organizational changes, based in principles as waste reduction and customer focus . These concepts may surprise somebody who does not know the business world, who might ask himself how it can be possible that organizations do things that are not needed instead of doing things that are of the customers' interest. It is clear that, at least in general terms, this is not done on purpose. A job is done because it is thought to be useful, as we can deduce from the rationality of the persons involved.However, in complex value streams, the percept...