Lean six sigma (LSS) is a data driven process improvement approach for waste minimization, cost effective processing and increasing overall performance. This study proposes a Bayesian Best Worst Method (BBWM) approach to rank critical failure factors inhibiting implementation of Lean Six Sigma in dairy processing industry. BBWM is an advanced Multi Criteria Decision Making Method (MCDM) which incorporates subjective judgement of decision makers to reduce uncertainty and complexity of decision-making process. The study is based on Bangladeshi dairy processing industry. Four main criteria are found through extensive literature review and experts’ opinion. These four main criteria have been ranked using BBWM. Each major criteria are divided into sub-criteria which are also ranked using the same approach. This study will be helpful for further analysis on LSS application in dairy processing industry.Lean six sigma (LSS) is a data driven process improvement approach for waste minimization, cost effective processing and increasing overall performance. This study proposes a Bayesian Best Worst Method (BBWM) approach to rank critical failure factors inhibiting implementation of Lean Six Sigma in dairy processing industry. BBWM is an advanced Multi Criteria Decision Making Method (MCDM) which incorporates subjective judgement of decision makers to reduce uncertainty and complexity of decision-making process. The study is based on Bangladeshi dairy processing industry. Four main criteria are found through extensive literature review and experts’ opinion. These four main criteria have been ranked using BBWM. Each major criteria are divided into sub-criteria which are also ranked using the same approach. This study will be helpful for further analysis on LSS application in dairy processing industry.Lean six sigma (LSS) is a data driven process improvement approach for waste minimization, cost effective processing and increasing overall performance. This study proposes a Bayesian Best Worst Method (BBWM) approach to rank critical failure factors inhibiting implementation of Lean Six Sigma in dairy processing industry. BBWM is an advanced Multi Criteria Decision Making Method (MCDM) which incorporates subjective judgement of decision makers to reduce uncertainty and complexity of decision-making process. The study is based on Bangladeshi dairy processing industry. Four main criteria are found through extensive literature review and experts’ opinion. These four main criteria have been ranked using BBWM. Each major criteria are divided into sub-criteria which are also ranked using the same approach. This study will be helpful for further analysis on LSS application in dairy processing industry.Lean six sigma (LSS) is a data driven process improvement approach for waste minimization, cost effective processing and increasing overall performance. This study proposes a Bayesian Best Worst Method (BBWM) approach to rank critical failure factors inhibiting implementation of Lean Six Sigma in dairy processing industry. BBWM is an advanced Multi Criteria Decision Making Method (MCDM) which incorporates subjective judgement of decision makers to reduce uncertainty and complexity of decision-making process. The study is based on Bangladeshi dairy processing industry. Four main criteria are found through extensive literature review and experts’ opinion. These four main criteria have been ranked using BBWM. Each major criteria are divided into sub-criteria which are also ranked using the same approach. This study will be helpful for further analysis on LSS application in dairy processing industry.