Statistics in Validating Root Causes Analysis
How to validate root causes in a lean sigma approach
Silvia Pederzolli
Milan, the 15th of april 2013
attivaRes
Define Opportunities
Measure Performance
Analyze Opportunity
Improve Performance
Control Performance
CCR’S
Objective
• • • • • Identify problem statement: what is wrong and why. Deviation from what is expected (targeted performance). How much/how often Effects on Customers. Find and validate the root causes that assure the elimination of “real” root causes.
Actions
•Identify Root Causes •Design Root Cause
Verification Analysis •Validate Root Causes
Deliverables
•Data Analysis •Process Maps •Validated Root Causes
attivaRes
1.
The major objective is to find the root causes
1. 2.
Source of Customer dissatisfaction Poor business result
2.
Through root causes analysis the team leads to the underlying source of defect and can change the process to permanently eliminate the problem
market
Process input
process
process
output
CCR’s
Output Variation = defect
attivaRes
Not easy to find Preconceived ideas for causes Pressure for quick solution Difficulty in collecting more data Wrong or apparent root causes will lead to wrong solutions
attivaRes
The fishbone diagram is useful to reach a common understanding of the problem. It is a strong tool to establish the relation between an effect and its main causes. It starts from the statement in the «head of the fish» Then the team determines major categories (the «bone») and brainstoms all possible causes
attivaRes
attivaRes
It turns brainstorming into practical solutions
brainstorming
Statistical results
Practical solutions
Verified root causes will lead to right solutions in the IMPROVE phase
Define Opportunities
Measure Performance
Analyze Opportunity
Improve Performance
Control Performance
CCR’S
attivaRes
«Root causes» mean «hypothesis» of relationship between two variables and
Silvia Pederzolli
Milan, the 15th of april 2013
attivaRes
Define Opportunities
Measure Performance
Analyze Opportunity
Improve Performance
Control Performance
CCR’S
Objective
• • • • • Identify problem statement: what is wrong and why. Deviation from what is expected (targeted performance). How much/how often Effects on Customers. Find and validate the root causes that assure the elimination of “real” root causes.
Actions
•Identify Root Causes •Design Root Cause
Verification Analysis •Validate Root Causes
Deliverables
•Data Analysis •Process Maps •Validated Root Causes
attivaRes
1.
The major objective is to find the root causes
1. 2.
Source of Customer dissatisfaction Poor business result
2.
Through root causes analysis the team leads to the underlying source of defect and can change the process to permanently eliminate the problem
market
Process input
process
process
output
CCR’s
Output Variation = defect
attivaRes
Not easy to find Preconceived ideas for causes Pressure for quick solution Difficulty in collecting more data Wrong or apparent root causes will lead to wrong solutions
attivaRes
The fishbone diagram is useful to reach a common understanding of the problem. It is a strong tool to establish the relation between an effect and its main causes. It starts from the statement in the «head of the fish» Then the team determines major categories (the «bone») and brainstoms all possible causes
attivaRes
attivaRes
It turns brainstorming into practical solutions
brainstorming
Statistical results
Practical solutions
Verified root causes will lead to right solutions in the IMPROVE phase
Define Opportunities
Measure Performance
Analyze Opportunity
Improve Performance
Control Performance
CCR’S
attivaRes
«Root causes» mean «hypothesis» of relationship between two variables and