Combining Lean and Six Sigma in practice

This thesis focuses on contributing to a framework around improvement methodologies combining Lean Manufacturing and Six Sigma often referred to as Lean Sigma or Lean Six Sigma. It also gives insight into one practical application and interpretation of such a combination by action research at Ericsson Borås who utilises a mixed approach in their Ericsson Production System initiative. Through a holistic study of both Lean Manufacturing and Six Sigma attempts are made to dissect each improvement program into several important pieces contributing to the success of the method. Theoretical combinations, potential gains of combinations and synergetic effects are reviewed. This is followed by a description of the improvement environment of Ericsson Borås and the authors experience from participating in an improvement project around a repair and return process. Here several observations regarding the strengths and weaknesses of contemporary Lean Sigma compositions at Ericsson Borås are shared. Through combining the developed theoretical framework with empirical observations it is possible to draw conclusions on how strengths and weaknesses discovered are related to the content of the Lean Sigma compositions. This provides insight into consequences of certain Lean Sigma designs and gives guidance for modular thinking around the contraction of Lean Sigma programs