Process Mapping in Lean Six Sigma: Types, Symbols & Best Practices

Many organizations struggle with inefficient processes, but the root problem is often simple. Teams do not fully understand how their processes actually work.

When workflows involve multiple departments, handoffs, and decision points, it becomes difficult to see where delays, errors, or unnecessary steps occur. Without a clear view of the process, improvement efforts become guesswork.

This is where process mapping lean six sigma methods become essential.

Process mapping is a visual technique used to illustrate how work flows from start to finish. By mapping each step of a workflow, teams can identify inefficiencies, understand dependencies, and uncover opportunities for improvement.

It is considered one of the most important tools used in Lean Six Sigma projects. In fact, many improvement initiatives begin with visualizing processes before any data analysis or redesign takes place. If you want to explore other tools used in process improvement, the guide on lean six sigma tools list explains the foundational techniques professionals use to analyze and improve workflows.

In this article, we will explore how process mapping works in Lean Six Sigma, the different types of maps used in improvement projects, the common symbols used to build process diagrams, and best practices for creating effective process maps.

What Is Process Mapping in Lean Six Sigma?

Process mapping in Lean Six Sigma is the practice of visually documenting the steps involved in a workflow.

Instead of describing a process in long written instructions, process maps use diagrams to show how work flows between activities, decisions, and outputs.

These visual diagrams help teams understand how tasks move through a system and where inefficiencies may occur.

In Lean Six Sigma, lean process maps are commonly used to:

• Document existing workflows
  • Identify process bottlenecks
  • Reveal redundant steps
  • Improve communication between departments
  • Support process improvement initiatives

By turning a complex workflow into a clear visual structure, process mapping allows teams to see patterns that may not be obvious when reading documentation or analyzing raw data.

Process maps are often used throughout Lean Six Sigma projects, particularly during the Measure and Analyze phases of the DMAIC framework.

Why Process Mapping Matters in Process Improvement

Improving a process without understanding how it works rarely produces meaningful results.

Process mapping provides a foundation for improvement by revealing how work flows through an organization.

One of the most valuable aspects of process mapping is its ability to identify inefficiencies.

When a process is visualized step by step, teams can quickly identify areas where:

• Work is delayed
  • Steps are duplicated
  • Approvals slow progress
  • Communication breaks down
  • Errors occur frequently

These insights allow improvement teams to focus on the real causes of inefficiency rather than making assumptions.

Process maps also improve collaboration.

Many operational processes involve multiple departments, and each team may only see part of the workflow. When a process map is created collaboratively, it helps everyone understand how their work connects to the larger system.

This shared understanding is essential when teams begin redesigning processes to improve efficiency and quality.

How Process Mapping Fits Into the DMAIC Framework

Lean Six Sigma improvement projects follow a structured methodology known as DMAIC.

DMAIC stands for:

• Define
• Measure
• Analyze
• Improve
• Control

Process mapping supports several of these phases.

Define Phase

During the Define stage, teams often create high level maps to understand the process being analyzed. Tools like SIPOC diagrams are commonly used here to provide a structured overview.

If you want to understand how SIPOC diagrams help define processes at a high level, the guide on six sigma sipoc explains how teams use this tool to clarify process boundaries before deeper analysis begins.

Measure Phase

In the Measure phase, more detailed process maps are created to document each step of the workflow. This allows teams to understand how the process currently operates.

Analyze Phase

During analysis, process maps help identify bottlenecks, delays, and unnecessary steps that contribute to inefficiencies.

Improve Phase

Once problems are identified, process maps can be redesigned to create improved workflows.

Control Phase

Finally, updated process maps may be used as documentation to standardize improved processes.

Because process maps evolve throughout the improvement lifecycle, they remain valuable from the beginning of a project through its final implementation.

Types of Process Maps Used in Lean Six Sigma

Different situations require different types of process maps. Lean Six Sigma practitioners use several mapping formats depending on the level of detail required.

High-Level Process Map

A high level process map provides a simplified overview of a workflow.

It focuses on major stages of a process rather than detailed tasks.

High level maps are useful when teams want to quickly understand how a system operates without analyzing every individual step.

These maps are often used during early project discussions or when explaining processes to stakeholders.

Detailed Process Map

Detailed process maps expand on high level diagrams by including each step involved in the workflow.

These maps typically show:

• Individual tasks
  • Decision points
  • Inputs and outputs
  • Process sequences

Because they reveal how tasks interact with one another, detailed process maps are especially useful for identifying inefficiencies and opportunities for improvement.

Swimlane Process Map

Swimlane diagrams are designed to show how responsibilities are divided across departments or individuals.

Each “lane” represents a team or role responsible for a specific part of the workflow.

Swimlane maps help improvement teams understand:

• Who performs each task
  • Where handoffs occur
  • Where communication breakdowns may happen

These diagrams are particularly useful for analyzing cross functional processes.

Value Stream Mapping

Value stream mapping is one of the most powerful forms of process mapping used in Lean Six Sigma.

While standard process maps focus on workflow steps, value stream mapping basics focus on identifying waste within a process.

Value stream maps analyze the entire flow of materials and information required to deliver value to the customer.

These maps help teams identify:

• Delays between activities
  • Excess inventory
  • Redundant process steps
  • Non value adding activities

Because of this focus on efficiency, value stream mapping plays an important role in Lean improvement initiatives.

Common Process Mapping Symbols Explained

Process maps use standardized symbols to represent different types of activities and decisions. These symbols help teams quickly understand how a process flows without needing lengthy explanations.

Using consistent symbols also improves communication across teams, especially when multiple departments are involved in an improvement project.

Below are some of the most common symbols used in process mapping lean six sigma diagrams.

These symbols make process diagrams easier to interpret. When teams follow a consistent structure, stakeholders can quickly understand how work flows through the system.

Standardization also helps organizations document processes more effectively, especially when improvement initiatives require collaboration between different departments.

How to Create a Process Map Step by Step

Creating a process map does not require complex software or advanced technical skills. The key is to follow a structured approach so the final diagram accurately represents the workflow.

Step 1: Define the Process Scope

Start by identifying the process you want to map.

Clearly define the starting point and ending point of the workflow. This prevents the project from becoming too broad.

For example, an order fulfillment process might begin when a customer places an order and end when the product is delivered.

Step 2: Gather Process Information

Next, collect information about how the process actually operates.

This often involves speaking with employees who perform the work, observing the workflow, and reviewing existing documentation.

Including multiple stakeholders ensures the process map reflects reality rather than assumptions.

Step 3: List All Process Steps

Once the information is gathered, list the individual steps involved in completing the process.

These steps may include activities such as reviewing requests, processing data, approving actions, or delivering results.

At this stage, focus on identifying all relevant steps before worrying about the visual structure.

Step 4: Arrange Steps in Logical Order

After identifying the steps, organize them in the order they occur.

This sequence forms the basic structure of the process map.

Arrows are typically used to connect the steps and show how work flows from one activity to the next.

Step 5: Identify Decision Points

Many processes involve decision points where different paths may occur depending on conditions.

For example, a customer support process may include a decision step such as whether the issue requires escalation.

Decision points are usually represented with diamond shaped symbols.

Step 6: Review and Validate the Map

Once the process map is complete, review it with stakeholders.

Employees who work within the process can confirm whether the map accurately represents the workflow.

This validation step is important because it ensures the diagram reflects the real process rather than an idealized version.

Process Mapping Example in Lean Six Sigma

To better understand how process mapping works, consider a simple example involving a customer support system.

Imagine a company that receives technical support requests through an online portal.

The workflow might look like this:

At first glance, this process may appear efficient.

However, when mapped visually, the team may discover issues such as repeated handoffs between departments or delays in ticket assignment.

These insights allow improvement teams to identify opportunities for redesigning the workflow and improving service response times.

Process Mapping vs SIPOC

Process mapping and SIPOC diagrams are both important tools in Lean Six Sigma, but they serve different purposes.

SIPOC diagrams provide a high-level overview of a process, while process maps examine the workflow in greater detail.

The comparison below highlights the difference.

Many Lean Six Sigma projects begin with a SIPOC diagram to understand the overall process structure.

Once the scope is defined, teams create more detailed process maps to analyze the workflow step by step.

If you want to explore how SIPOC diagrams help teams define processes before mapping them in detail, the article on six sigma sipoc explains how this tool supports the early stages of improvement projects.

Best Practices for Effective Process Mapping

Creating a process map is relatively simple, but creating an effective one requires thoughtful execution.

Several best practices can improve the quality of process maps used in Lean Six Sigma projects.

Keep the map clear and simple

Avoid adding unnecessary complexity. A process map should make the workflow easier to understand, not harder.

Involve the people who perform the work

Employees closest to the process often have the most accurate knowledge of how tasks are performed.

Their input ensures the process map reflects reality.

Focus on the current process first

Improvement projects should begin by documenting the current state of the process before designing future improvements.

This helps teams identify the true sources of inefficiency.

Validate the map with real data

Process maps should be supported by data whenever possible. Metrics such as cycle time, error rates, or delays can provide valuable context.

Use mapping tools when appropriate

While simple diagrams can be drawn on whiteboards, many organizations use digital tools to create process maps that can be easily updated and shared.

Following these best practices ensures that process maps become valuable tools for analysis rather than just documentation.

Conclusion: Why Process Mapping Is Essential in Lean Six Sigma

Process improvement begins with understanding how work actually happens.

Process mapping provides the visual clarity needed to analyze workflows, identify inefficiencies, and design better systems.

By illustrating how tasks move through an organization, process mapping lean six sigma techniques help teams uncover hidden problems such as delays, redundant activities, and communication breakdowns.

These insights form the foundation for meaningful improvement initiatives.

When combined with other Lean Six Sigma tools, such as SIPOC diagrams and data analysis techniques, process mapping becomes an essential part of the improvement process.

Professionals learning Lean Six Sigma often begin with these foundational methods because they provide the clarity needed to solve complex operational problems.

Training programs offered by Lean Six Sigma Global help professionals develop the skills needed to apply process mapping and other improvement tools in real business environments, enabling organizations to achieve measurable gains in efficiency, quality, and performance.