Untangling Inefficiency: How to Use a Spaghetti Diagram to Improve Workflow

In Lean thinking, reducing waste is everything — and motion is one of the sneakiest forms of it. Whether it's a factory worker retrieving tools across the room or a nurse zigzagging through a ward, unnecessary movement slows everything down. That’s where the Spaghetti Diagram comes in — a simple but powerful visual tool that maps the chaos and helps you find flow.

What Is a Spaghetti Diagram?

A Spaghetti Diagram is a visual map of the physical flow of people, products, or information through a process. It’s called “spaghetti” because the drawn lines, representing movement, often look like a tangled bowl of pasta.

You use it to track actual paths — not what’s supposed to happen, but what really does. This tool helps you see where excess motion and inefficiencies lie in your workspace layout or process design.

Why Use a Spaghetti Diagram?

Here’s what a Spaghetti Diagram helps you discover:

• Long, repetitive travel routes

• Inefficient workstation layouts

• Bottlenecks or collision points

• Areas of frequent backtracking

• Excess walking or unnecessary handoffs

In Lean terms, it targets two key wastes: motion and transportation.

How to Create a Spaghetti Diagram

Step 1: Start with a floor plan: Draw or print the layout of your work area — office, factory floor, lab, clinic, etc.

Step 2: Observe the process: Pick a person, product, or document and follow their path during a real process cycle. Walk the Gemba if needed.

Step 3: Trace the movement: Use a pen or marker to draw lines across the layout, connecting each point the subject visits.

Step 4: Add detail: Label each step or stop. You can use timestamps or color-code for different trips or people.

Step 5: Analyze the pattern: Look for:

• Loops or frequent returns

• Long distances between steps

• Overlapping paths from different users

• Opportunities to rearrange for efficiency

Example in Action: Pharmacy Pick-Up Counter

A pharmacy technician walks:

1. From the counter to the shelves (3 times)

2. Back to check with the pharmacist

3. Over to the payment terminal

4. Then returns to the counter

When mapped, this looks like a loop-de-loop. A spaghetti diagram shows this inefficiency visually and sparks solutions, like placing a cart near the counter or batching pickups.

Benefits of Spaghetti Diagrams

• Quick to create

• Low-tech, high-impact

• Helps justify layout changes

• Makes inefficiencies visible

• Engages frontline staff

After the Diagram: What’s Next?

Once you identify inefficient motion:

• Rearrange tools and materials closer to where they’re used

• Minimize back-and-forth by combining tasks

• Use mobile workstations or carts

• Standardize best routes and flows

Tip: Combine with Time Study

Want even more insight? Pair your spaghetti diagram with a time and motion study to measure how long each trip takes. This gives you hard data to support your improvements.

Final Thoughts

The Spaghetti Diagram is a deceptively simple Lean tool that helps you literally “draw out” inefficiencies in motion. It’s not about perfection — it’s about awareness. Once you can see the waste, you can design it out of your process.