PARETO DIAGRAM PREPARATION AS PER JUSE GUIDELINE

INTRODUCTION

In the world of Total Quality Management, problem-solving must always be based on facts and priorities rather than assumptions and emotions. One of the most powerful tools that supports this philosophy is the Pareto Diagram.

The Pareto Diagram is one of the Seven Basic Quality Control Tools promoted extensively by Union of Japanese Scientists and Engineers (JUSE), the organization responsible for propagating Japanese quality management practices worldwide and administering the Deming Prize.

JUSE considers the Pareto Diagram not merely as a chart, but as a management prioritization tool that enables organizations to identify the “Vital Few” causes responsible for the majority of problems.

The principle behind the Pareto Diagram is based on the famous 80:20 rule.

80\%\ \text{of problems are often caused by} \ 20\%\ \text{of causes}

This principle helps management focus on the most important areas instead of spreading resources equally across all issues.

ORIGIN OF THE PARETO PRINCIPLE

The Pareto Principle originated from the observations of Italian economist Vilfredo Pareto, who noticed that approximately 80% of wealth in Italy was owned by 20% of the population.

Later, quality experts applied this concept in manufacturing and management systems and discovered that:

• A few causes create most defects
• A few machines create most breakdowns
• A few suppliers create most quality issues
• A few problems create most customer complaints

Japanese industries, especially companies like Toyota Motor Corporation, adopted Pareto analysis deeply within their TQM systems.

WHAT IS A PARETO DIAGRAM?

A Pareto Diagram is a special type of bar chart where:

• Categories are arranged in descending order
• Bars represent frequency or impact
• A cumulative percentage line is drawn
• The chart identifies the major contributors

The diagram visually separates:

• Vital Few
• Useful Many (or Trivial Many)

WHY JUSE EMPHASISES PARETO DIAGRAM

JUSE strongly believes that:

“Management must focus on priorities.”

Without prioritization:

• Resources get diluted
• Teams lose direction
• Improvement becomes slow
• Cost increases
• Results become insignificant

Pareto analysis enables organizations to:

• Focus correctly
• Use data-based decision making
• Improve productivity
• Reduce losses
• Accelerate improvement activities

OBJECTIVES OF A PARETO DIAGRAM

IDENTIFY MAJOR CONTRIBUTORS

The primary objective is to identify the few categories contributing to the majority of the problem.

Example:

• 2 defects may contribute 75% rejection.

PRIORITIZE IMPROVEMENT ACTIVITIES

Instead of improving everything simultaneously, organizations focus on:

• Highest impact areas first

This supports:

• Effective resource utilization
• Faster improvement
• Better ROI

SUPPORT FACT-BASED MANAGEMENT

JUSE philosophy emphasizes:

• Decisions must be based on actual data.

Pareto diagrams convert raw data into:

• Visual management information

SUPPORT PDCA ACTIVITIES

Pareto analysis is heavily used in:

• Plan
• Do
• Check
• Act cycles

It helps measure:

• Before improvement
• After improvement

COMPONENTS OF A PARETO DIAGRAM

A proper Pareto Diagram contains several important elements.

TITLE

The title must clearly mention:

• Subject
• Area
• Period

Example:

CUSTOMER COMPLAINT PARETO – APRIL 2025

X-AXIS

The X-axis contains:

• Categories of defects/problems

Example:

• Scratch
• Dent
• Crack
• Rust

LEFT Y-AXIS

The left vertical axis represents:

• Frequency
• Quantity
• Cost
• Downtime

RIGHT Y-AXIS

The right vertical axis represents:

• Cumulative Percentage (%)

This scale must end at:

• 100%

BARS

The bars represent:

• Frequency of occurrence

As per JUSE guideline:

• Bars must touch each other
• No gap should exist

Reason:
The categories are part of the same total population.

CUMULATIVE PERCENTAGE LINE

The cumulative line shows:

• Running percentage contribution

The line must:

• Start from first category
• End exactly at 100%

STEP-BY-STEP PREPARATION OF PARETO DIAGRAM AS PER JUSE

STEP 1 — DEFINE THE PROBLEM CLEARLY

A vague problem leads to poor analysis.

The problem statement should define:

• What is being analyzed
• Which department/process
• Time period
• Measurement criteria

Example:

• Customer complaints from April 2025
• Rejection defects in radiator assembly
• Breakdown analysis in brazing furnace

STEP 2 — COLLECT FACTUAL DATA

JUSE emphasizes:

“Go to Gemba and collect actual data.”

The data should be:

• Reliable
• Sufficient
• Traceable
• Objective

Data may include:

• Number of defects
• Downtime minutes
• Customer complaints
• Financial loss
• Accident frequency

STEP 3 — CLASSIFY THE DATA

Data should be grouped into meaningful categories.

Common classification methods:

• Defect-wise
• Machine-wise
• Supplier-wise
• Shift-wise
• Operator-wise
• Customer-wise

JUSE cautions that categories should:

• Not overlap
• Be easy to understand
• Represent actual conditions

STEP 4 — ARRANGE DATA IN DESCENDING ORDER

This is one of the most critical requirements.

The highest contributor must appear first.

Example:

Defect Type	Frequency
Fin Leakage	42
Brazing Issue	28
Dent	15
Core Blockage	7
Paint Issue	5
Others	3

The “Others” category must always remain:

• At the end

STEP 5 — CALCULATE CUMULATIVE FREQUENCY

The cumulative frequency is calculated progressively.

Example:

Defect	Frequency	Cumulative Frequency
Fin Leakage	42	42
Brazing Issue	28	70
Dent	15	85
Core Blockage	7	92

STEP 6 — CALCULATE CUMULATIVE PERCENTAGE

Formula:

\text{Cumulative Percentage} = \frac{\text{Cumulative Frequency}}{\text{Total Frequency}} \times 100

If total complaints are 100:

• 42 defects = 42%
• 70 defects = 70%
• 85 defects = 85%

The final cumulative percentage must always equal:

• 100%

STEP 7 — DRAW THE BARS

The bars represent:

• Frequency or quantity

JUSE graphical rules:

• Bars arranged highest to lowest
• Bars touching each other
• Uniform width
• Clear labeling

STEP 8 — DRAW THE CUMULATIVE LINE

The cumulative percentage line is plotted using:

• Right-side percentage scale

The line visually shows:

• Contribution accumulation

STEP 9 — IDENTIFY THE VITAL FEW

Generally:

• 70–80% contributors are treated as “Vital Few.”

Example:

• Fin Leakage + Brazing Issue = 70%

Therefore:

• Improvement priority must focus there first

JUSE GRAPHICAL GUIDELINES

BARS MUST TOUCH EACH OTHER

No gaps should exist between bars.

Reason:
The categories represent continuous components of total data.

DESCENDING ORDER IS MANDATORY

Random arrangement destroys Pareto logic.

CUMULATIVE LINE MUST END AT 100%

This indicates:

• Total population coverage

TITLE, PERIOD AND DATA SOURCE MUST BE SHOWN

A professional Pareto must mention:

• Data source
• Location
• Study period

INTERPRETATION OF PARETO DIAGRAM

The real power of Pareto lies in interpretation.

Management should ask:

• Which causes contribute most?
• What are the major losses?
• Which problems require immediate action?

The focus must always be:

• Vital Few first

This is the core philosophy of JUSE.

COMMON MISTAKES IN PARETO PREPARATION

USING INSUFFICIENT DATA

Small sample size leads to misleading conclusions.

MIXING DIFFERENT UNITS

Example:

• Combining frequency and cost together

This is incorrect.

POOR CLASSIFICATION

Overlapping categories reduce clarity.

NOT USING DESCENDING ORDER

Without descending order:

• Pareto loses meaning.

LEAVING GAPS BETWEEN BARS

This violates JUSE graphical standards.

APPLICATIONS OF PARETO DIAGRAM

Pareto analysis is widely used in:

• Manufacturing
• Supplier Quality
• TPM
• Six Sigma
• Customer complaints
• Safety analysis
• Warranty analysis
• Cost reduction
• Inventory management

PARETO DIAGRAM IN DEMING EXAMINATION

During Deming Prize assessment, examiners verify:

• Whether data is factual
• Whether prioritization is logical
• Whether corrective action is linked
• Whether improvements are measurable
• Whether Pareto supports management decisions

The chart must not be prepared merely for presentation purposes.

It should demonstrate:

• Actual problem-solving

PRACTICAL EXAMPLE FROM TATA TOYO RADIATOR

Suppose customer complaints are:

Complaint Type	Quantity
Fin Leakage	42
Brazing Issue	28
Dent	15
Core Blockage	7
Paint Issue	5
Others	3

Total complaints = 100

Pareto analysis shows:

• Fin Leakage + Brazing Issue = 70%

Therefore management should prioritize:

• Brazing process improvement
• Leak testing
• Handling systems
• Standard operating procedures

instead of distributing equal effort everywhere.

BENEFITS OF PARETO DIAGRAM

IMPROVES DECISION MAKING

Management can prioritize logically.

REDUCES RESOURCE WASTAGE

Efforts focus on high-impact areas.

IMPROVES VISUAL MANAGEMENT

Problems become easier to understand.

SUPPORTS CONTINUOUS IMPROVEMENT

Improvement becomes systematic and measurable.

ENHANCES MANAGEMENT EFFECTIVENESS

Teams focus on what matters most.

CONCLUSION

The Pareto Diagram is one of the most powerful tools in modern quality management. Under the guidance of Union of Japanese Scientists and Engineers, it has become an essential component of:

• TQM
• Kaizen
• QC Circle activities
• TPM
• Six Sigma
• Deming-based management systems

Its strength lies in simplicity, visualization, and prioritization.

JUSE philosophy teaches that:

“Not all problems are equally important.”

Organizations that correctly use Pareto analysis can:

• Improve faster
• Reduce waste
• Focus strategically
• Strengthen quality culture
• Achieve operational excellence

The Pareto Diagram ultimately supports the Japanese philosophy of:

“Management by Facts and Priorities.”