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Root Cause Analysis In The Lean Framework

Updated: Dec 6, 2023

Root cause analysis (RCA) is a systematic process to identify underlying causes of problems within an organisation. It’s a critical component of problem-solving and plays a pivotal role within Lean tools to achieve operational excellence through Continuous Improvement.

Understanding root cause analysis

RCA helps organisations dig deep into the root causes of inefficiencies, defects, or other issues in their processes – ultimately leading to more effective and sustainable solutions.

Root Cause Analysis In The Lean Framework

The importance of root cause analysis

Why is root cause analysis essential within the Lean framework?

  1. Lean principles emphasise eliminating waste in all forms, including defects, overproduction, waiting times, and more. Identifying the root causes of wasteful practices enables organisations to make data-driven improvements.

  2. Continuous Improvement is a central tenet of Lean – by addressing root causes, organisations can implement changes that lead to Continuous Improvement in processes and operations.

  3. Instead of merely addressing symptoms, RCA aims to prevent problems from recurring by targeting their origins. This proactive approach aligns with Lean’s philosophy of preventing issues before they impact quality or efficiency.

  4. RCA relies on data and evidence; it’s a structured and objective process – bringing it in line with Lean’s emphasis on making decisions based on data rather than assumptions or opinions.

Tools and techniques for RCA

Effective root cause analysis relies on different tools and techniques, each suited to different types of problems, including:

1. ‘5 Whys’ Analysis:

The 5 whys technique involves asking “why” repeatedly to drill down to the root cause of a problem. It encourages deeper thinking to uncover underlying issues.

2. Fishbone Diagram (Ishikawa Diagram):

Fishbone Diagram

The Fishbone Diagram (or the Ishikawa Diagram) is a powerful visual tool employed in root cause analysis to systematically dissect and analyse the dynamic nature of problems. This diagrammatic representation helps structure and categorise potential causes of an issue into distinct categories – such as people, process, equipment, materials, and environment.

The Fishbone Diagram offers a structured approach to problem-solving, enabling teams to consider a wide range of factors contributing to the observed problem.

3. Pareto Analysis:

The Pareto Principle (often called the 80/20 rule) suggests that 80% of problems result from 20% of causes. Pareto Analysis prioritises efforts by focusing on the most significant contributing factors.

4. Failure Mode and Effects Analysis (FMEA):

FMEA assesses the potential failure modes of a process, product, or system and evaluates their impact and likelihood. It helps prioritise and address potential root causes to prevent failures.

5. Control Charts:

Control Charts are graphical tools that monitor process performance over time, making it easier to identify deviations and potential root causes.

Practical application: Decreasing production downtime in a manufacturing plant

Problem statement: A manufacturing plant was experiencing frequent downtime, leading to production delays and increased costs.

Root cause analysis:

‘5 Whys’ Analysis:

The team asked “why” five times to uncover the root cause…

  1. Why is there downtime? The machine broke down

  2. Why did the machine break down? Lack of preventive maintenance

  3. Why was preventive maintenance lacking? Insufficient resources

  4. Why were resources insufficient? Budget cuts

  5. Why were there budget cuts? Economic downturn

Fishbone Diagram:

The team categorised potential causes into maintenance, resources, and external factors. They then identified budget cuts as a primary factor.


Based on the RCA findings, the organisation took several actions:

  1. Increased budget allocation for maintenance and resources

  2. Implemented a proactive preventive maintenance schedule

  3. Developed contingency plans for economic downturns


Production downtime decreased significantly, improving efficiency and cost savings. The organisation saw reduced waste and an increase in overall equipment effectiveness, aligning with Lean principles.

Using root cause analysis in Lean practices

Root cause analysis is a powerful tool in the Lean framework, enabling organisations to uncover the underlying causes of problems, eliminate waste, and drive Continuous Improvement. By using tools and techniques like the ‘5 Whys’, Fishbone Diagrams, and the Pareto Analysis, organisations can make informed, data-driven decisions to address root causes and enhance their processes and operations in line with Lean principles.

To discover more about root cause analysis and Lean Continuous Improvement, get in touch with our team.

Reach out to us at 0161 533 1617, email, or on our website.



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