Six Sigma Framework and Project Selection

Learning Objectives

Explain the Six Sigma improvement framework.
Describe the five phases of DMAIC.
Understand the purpose and outputs of each DMAIC phase.
Distinguish between a business problem and a Six Sigma project.
Identify characteristics of a suitable Green Belt project.
Understand project-selection criteria.
Evaluate customer and business impact.
Assess strategic alignment and project feasibility.
Understand the importance of data availability.
Use a Project Selection Matrix to compare potential projects.
Develop a basic Business Case for project selection.
Recognize projects that may not be suitable for a Green Belt DMAIC project.

1. Introduction

Six Sigma is a structured, data-driven approach for improving processes, reducing variation, preventing defects, and increasing customer and business performance.

A successful Six Sigma project does not begin simply by selecting a statistical tool. It begins by identifying the right problem and determining whether that problem is appropriate for a structured improvement project.

For a Green Belt practitioner, two capabilities are particularly important:

Understanding the DMAIC improvement framework.
Selecting a project that is meaningful, measurable, feasible, and aligned with organizational needs.

Poor project selection can result in wasted resources, lack of measurable results, scope expansion, and difficulty completing the project.

Therefore, the basic principle is:

Select the right problem before applying the right improvement tools.

2. Concept / Theory

2.1 The Six Sigma Improvement Framework

Six Sigma provides a disciplined framework for improving an existing process.

For process improvement projects, the primary framework is DMAIC:

D — Define
M — Measure
A — Analyze
I — Improve
C — Control

DMAIC provides a logical sequence for understanding a problem, measuring current performance, identifying causes, implementing improvements, and sustaining the results.

The phases are connected. The output of one phase provides important information for the next phase.

2.2 Define

The Define phase answers:

What problem are we trying to solve?

The team establishes:

The business problem.
The customer problem.
The business need.
The project objective.
The project scope.
Key stakeholders.
Preliminary measures of success.

Typical Define-phase outputs include:

Problem Statement.
Business Case.
Project Goal.
Project Scope.
Customer Requirements.
Project Charter.

A clearly defined problem provides direction for the entire project.

2.3 Measure

The Measure phase answers:

How is the process performing today?

The team establishes the current-state performance using reliable data.

Typical activities include:

Defining performance measures.
Identifying data requirements.
Collecting data.
Establishing a baseline.
Understanding process variation.
Evaluating the measurement process where appropriate.
Determining the magnitude of the performance gap.

Examples of measures include:

Defect rate.
Cycle time.
Process yield.
Throughput.
Customer complaints.
Cost.
Productivity.
Process capability.

The objective is to understand the current condition rather than relying on assumptions.

2.4 Analyze

The Analyze phase answers:

Why is the problem occurring?

The team examines data and process information to identify the factors contributing to the problem.

Possible tools include:

Pareto Analysis.
Cause-and-Effect Diagram.
5 Whys.
Scatter Diagram.
Hypothesis Tests.
Regression Analysis.
ANOVA.
Process analysis.

A critical principle is to distinguish between a suspected cause and a verified cause.

A brainstorming session may produce possible causes, but data and analysis should be used to determine which factors actually contribute to the problem.

2.5 Improve

The Improve phase answers:

What changes can improve process performance?

Once important causes have been identified, the team develops and evaluates potential solutions.

Activities may include:

Generating improvement ideas.
Evaluating alternative solutions.
Conducting risk assessment.
Testing solutions through pilots.
Reducing process waste.
Reducing variation.
Implementing mistake-proofing.
Optimizing process settings.
Standardizing improved methods.

The objective is not simply to make a change, but to demonstrate that the change improves the relevant performance measure.

2.6 Control

The Control phase answers:

How will the improvement be sustained?

An improvement that disappears after the project is completed is not a sustained improvement.

Control activities may include:

Control Plans.
Standard Operating Procedures.
Process monitoring.
Control charts where appropriate.
Visual controls.
Training.
Performance dashboards.
Defined process ownership.
Escalation procedures.
Periodic performance reviews.

The purpose of Control is to make the improved process the normal way of working.

2.7 DMAIC as a Logical Improvement Cycle

The five phases can be viewed as a sequence of questions:

DMAIC Phase	Fundamental Question
Define	What problem are we solving?
Measure	How is the process performing?
Analyze	Why is the problem occurring?
Improve	What changes can improve performance?
Control	How will we sustain the improvement?

DMAIC therefore provides discipline to the improvement process.

It helps prevent teams from jumping directly from:

Problem → Solution

Instead, the team follows:

Problem → Measurement → Analysis → Verified Causes → Improvement → Control

3. Key Topics

3.1 Business Problem Versus Six Sigma Project

A business problem is not automatically a Six Sigma project.

For example:

Business Problem:
Customer complaints regarding delayed deliveries have increased.

This describes an organizational problem.

A potential Six Sigma project might be:

Project:
Reduce the percentage of customer orders delivered after the promised date from the current baseline to the agreed target within a defined project period.

The project is more suitable because it establishes a measurable performance issue.

3.2 Characteristics of a Suitable Green Belt Project

A suitable Green Belt project generally has the following characteristics:

1. Real Business Problem

The project addresses an actual performance issue rather than an artificial exercise.

2. Measurable Performance Gap

The problem can be measured using appropriate data.

3. Meaningful Impact

Improvement can provide meaningful customer, operational, financial, quality, or strategic benefits.

4. Feasible Scope

The project is large enough to justify structured improvement but small enough for the Green Belt team to manage.

5. Available or Obtainable Data

The team can obtain reliable information needed to understand the process and evaluate improvement.

6. Process Ownership

There is an identifiable process owner who can support implementation and sustainment.

7. Organizational Relevance

The project is connected to organizational priorities or important process-performance requirements.

8. Management Support

Appropriate stakeholders are willing to provide time, resources, access, and decision-making support.

3.3 Project Selection Criteria

Potential projects can be evaluated using several criteria.

Important criteria include:

Business impact.
Customer impact.
Financial impact.
Strategic alignment.
Data availability.
Technical feasibility.
Resource availability.
Project scope.
Management support.
Implementation risk.
Expected benefit.

Not every organization will assign the same weight to every criterion.

The selection criteria should reflect the organization’s priorities.

3.4 Business Impact

A project should address a problem that matters to the organization.

Potential business impacts include:

Reduced operating cost.
Improved productivity.
Reduced defects.
Reduced cycle time.
Increased capacity.
Improved delivery performance.
Reduced customer complaints.
Improved process reliability.

3.5 Customer Impact

Six Sigma places strong emphasis on customer requirements.

A project may be particularly relevant when it affects:

Product quality.
Service quality.
Delivery time.
Reliability.
Accuracy.
Responsiveness.
Customer complaints.
Customer satisfaction.

Customer impact should be considered alongside internal operational benefits.

3.6 Financial Impact

Where appropriate, the financial implications of a project should be estimated.

Potential benefits include:

Cost reduction.
Revenue protection.
Reduced rework.
Reduced scrap.
Reduced warranty cost.
Reduced overtime.
Reduced processing cost.
Improved capacity utilization.

Financial estimates should be based on reasonable and traceable assumptions.

3.7 Strategic Alignment

A project should support important organizational objectives where possible.

For example, if an organization has identified:

Strategic Objective: Improve customer responsiveness.

A project focused on reducing customer-service response time may have stronger strategic relevance than an unrelated improvement opportunity.

Strategic alignment helps ensure that Six Sigma resources are directed toward important organizational priorities.

3.8 Data Availability

Data is fundamental to Six Sigma.

Before selecting a project, the team should determine:

What needs to be measured?
Does the required data exist?
Is the data accessible?
Is the data sufficiently reliable?
Can new data be collected?
How much time will data collection require?

A project may appear attractive but become difficult to execute if the required information cannot reasonably be obtained.

3.9 Project Scope

Scope defines the boundaries of the project.

A project that is too broad may become difficult to control.

For example:

Too Broad:
Improve the entire company’s customer service.

A more manageable project could be:

More Focused:
Reduce response time for email-based customer service requests handled by a defined service team.

A project that is too narrow may not justify the resources required.

The Green Belt should seek an appropriate balance.

4. Tools / Methodology

4.1 Project Selection Matrix

A Project Selection Matrix can be used to compare candidate projects systematically.

An organization can assign a weight to each criterion and then score each project.

For example:

Criterion	Weight	Project A	Project B	Project C
Business Impact	25%	4	5	2
Customer Impact	25%	5	5	1
Financial Impact	20%	3	5	2
Strategic Alignment	15%	4	5	2
Data Availability	10%	5	4	5
Feasibility	5%	5	4	5

The scoring scale could, for example, be:

1 = Very Low
2 = Low
3 = Moderate
4 = High
5 = Very High

The organization can calculate weighted scores and compare the candidate projects.

The matrix does not replace management judgment. It provides a structured basis for discussion and comparison.

4.2 Business Case Analysis

A Business Case explains why a project deserves organizational attention and resources.

A basic Business Case can consider:

Current condition.
Problem impact.
Customer impact.
Business impact.
Financial implications.
Strategic importance.
Project investment.
Expected benefits.
Risks and constraints.

A well-developed Business Case connects the project to measurable organizational value.

4.3 Preliminary Project Selection Process

A practical project-selection process can follow these steps:

Step 1 — Identify potential business problems

Gather improvement opportunities from customers, processes, employees, performance reports, audits, complaints, financial information, and strategic priorities.

Step 2 — Define the performance gap

Describe the difference between current performance and required or desired performance.

Step 3 — Assess customer impact

Determine whether customers are affected and how.

Step 4 — Assess business impact

Estimate operational and financial consequences.

Step 5 — Check strategic alignment

Determine whether the problem supports important organizational priorities.

Step 6 — Check data availability

Determine whether suitable data exists or can reasonably be collected.

Step 7 — Assess feasibility

Consider resources, process ownership, time, technical complexity, and organizational support.

Step 8 — Define preliminary scope

Establish reasonable boundaries.

Step 9 — Develop the Business Case

Document why the project should be undertaken.

Step 10 — Select the project

Use appropriate criteria and stakeholder review.

Step 11 — Develop the Project Charter

Once the project has been selected, formally define and organize the project.

5. Worked Example / Case Study

Case Study — Reducing Loan Approval Cycle Time

A financial-services organization receives complaints that customers are waiting too long for loan approvals.

Management identifies several potential improvement opportunities:

Reduce customer-service email response time.
Reduce loan-approval cycle time.
Reduce printing-paper consumption.
Reduce a minor clerical error occurring in an internal report.

The organization evaluates the opportunities.

Problem Identification

The loan-approval process has a measurable cycle-time problem.

The current process includes several activities:

Application Received → Document Verification → Credit Assessment → Approval → Customer Notification

Customers experience delays when applications remain in the process longer than expected.

Customer Impact

Long approval times may affect the customer experience and delay access to the requested service.

Business Impact

Long cycle times may also result in:

Increased customer complaints.
Additional follow-up work.
Increased workload.
Reduced process efficiency.
Potential loss of business opportunities.

Data Availability

The organization already records:

Application receipt date.
Processing dates.
Approval date.
Processing stage.
Application type.

Therefore, cycle-time data can potentially be analyzed.

Feasibility

The process has an identifiable owner, relevant personnel are available, and the process can be examined within a defined scope.

Preliminary Scope

The project might be scoped to:

Loan applications processed by a defined business unit during a specified period.

The project team can then proceed toward formal charter development.

This is an example of how a broad business concern can be converted into a measurable and manageable Six Sigma project.

6. Practical Application

Consider the following potential problems:

Problem A

Product defects have increased significantly during the last six months.

Questions:

Is the problem measurable?
What is the customer impact?
What is the business impact?
Is reliable data available?
Is the scope manageable?
Is there a process owner?

Problem B

Meetings frequently start late.

Questions:

How significant is the problem?
Can the impact be quantified?
Does it justify a Green Belt project?
Is the potential benefit meaningful?
Could the issue be resolved through routine management rather than a DMAIC project?

Problem C

Customer-service response time has increased.

Questions:

What is the current response time?
What is the required response time?
How many customers are affected?
What is the financial or operational impact?
What data is available?
Is the project within the team’s influence?

This exercise demonstrates that identifying a problem is only the beginning. The Green Belt must determine whether the problem is appropriate for structured improvement.

6.1 Projects to Approach with Caution

Some projects may not be appropriate for a Green Belt DMAIC project.

Examples include:

Solution Already Determined

If management has already decided exactly what solution must be implemented, there may be limited opportunity for DMAIC-based investigation.

Problem Cannot Be Measured

If performance cannot reasonably be measured, it becomes difficult to establish a baseline or demonstrate improvement.

Outside the Team’s Influence

A project may become difficult if the team has no practical influence over the process.

Excessively Large Project

A project involving an entire enterprise or multiple major processes may require a larger transformation program rather than a single Green Belt project.

Trivial Problem

A minor problem with negligible impact may not justify the time and resources of a formal Six Sigma project.

Routine Maintenance

Routine corrective actions or standard operational activities may not require a full DMAIC project.

6.2 Project Selection and the Project Charter

Project selection and Project Charter development are related but different activities.

Project Selection asks:

Which problem should we work on?

Project Charter asks:

How will we define and manage the selected project?

The sequence is therefore:

Identify Opportunities → Evaluate Projects → Select Project → Develop Charter → Execute DMAIC

The Project Charter will be addressed in detail in Lesson 3 — Project Charter Development.

6.3 Integrated View of Project Selection

The complete thought process can be represented as:

Identify Business Problem
↓
Confirm Customer / Business Impact
↓
Define Performance Gap
↓
Check Strategic Alignment
↓
Check Data Availability
↓
Assess Feasibility and Resources
↓
Define Preliminary Scope
↓
Develop Business Case
↓
Evaluate Candidate Projects
↓
Select Project
↓
Develop Project Charter
↓
Execute DMAIC

This sequence helps ensure that improvement resources are directed toward meaningful opportunities.

7. Lesson Summary

Six Sigma provides a structured, data-driven framework for process improvement.

For existing-process improvement, DMAIC provides the core methodology:

Define establishes the problem and project direction.
Measure establishes current performance and the baseline.
Analyze identifies and verifies important causes.
Improve develops and implements effective solutions.
Control sustains the improved performance.

Project selection is a critical activity before DMAIC begins.

A suitable Green Belt project should generally have:

A meaningful business or customer problem.
A measurable performance gap.
Potential impact.
Appropriate scope.
Available or obtainable data.
Process ownership.
Organizational relevance.
Adequate support and feasibility.

Tools such as the Project Selection Matrix and Business Case Analysis help organizations evaluate improvement opportunities systematically.

8. Lesson Learnt / Conclusion

A successful Six Sigma project begins with selecting the right problem.

The Green Belt should not begin with a favorite statistical tool or a predetermined solution. The project should begin with a meaningful performance gap, supported by evidence and connected to customer or business needs.

Good project selection prevents wasted effort and directs Six Sigma resources toward problems where measurable improvement can create meaningful value.

Green Belt Takeaway:

Select the right problem before applying the right tools.