Spaghetti Diagram: How to Draw One and What to Do With It

By Mirko Peters · 2026-11-11

A spaghetti diagram traces the real paths of people or parts on a floor plan. Learn how to draw one, read the tangles and cut walking and transport waste.

A spaghetti diagram is a drawing of the actual path that a person, a part or a vehicle takes across a floor plan. Tangled, crossing and long lines show unnecessary walking and transport. This guide is for continuous improvement managers who need a quick way to show walking waste and agree on what to change. You will learn how to draw one, how to read it, a worked example with distances, and how to follow up so the picture leads to a changed layout.

Key points

• A spaghetti diagram is a drawing of the actual path of a person, part or vehicle on a floor plan; tangled lines show unnecessary walking and transport.
• You draw it at the gemba while you watch the work, not from memory in an office, and you note distance, trips and stops.
• Measure the distance and the number of trips per shift, so that the waste has a size in metres and minutes, not only a look.
• Typical countermeasures are moving a store or bench closer, kitting material to the point of use, and giving tools a fixed place at the station.
• Draw the diagram again after the change, because the second picture proves the gain and shows the next knot.

What the diagram shows

The American Society for Quality (ASQ) defines a spaghetti diagram as a visual representation using a continuous flow line that traces the path of an item or activity through a process. It helps teams spot redundant steps and ways to speed up the work. ASQ's example is a health department office that studied the walking between frequent tasks and then rearranged work areas.

The Lean Enterprise Institute (LEI) describes a spaghetti chart as a simple drawing made at the gemba, the place where the work happens, that plots the path taken by a product as it travels through the steps along a value stream. Both descriptions agree on the main idea: you draw what really happens, with one unbroken line, and you let the shape of the line tell the story.

The name explains the look. When people walk back and forth between a store, a bench and a machine, the line looks like a plate of spaghetti. A clean flow looks like a few straight lines. In lean thinking, unneeded movement and transport are two of the eight wastes, because they take time and add no value for the customer.

How to draw a spaghetti diagram in six steps

You need a floor plan, a pen, a stopwatch or a phone, and the person who does the work. A simple spaghetti diagram template is enough: a printed layout with the stations named, a scale bar, a legend for colours and a small table for distance, trips and notes. Ask two team members to help, one to draw and one to time.

1. Choose the scope. Pick one process, one product family or one role, such as an assembler, a material handler or a nurse. A diagram that tries to show everyone becomes unreadable.
2. Get a floor plan to scale. Print a plan or draw one with a tape measure. Mark the stations, stores, benches, doors and aisles.
3. Go to the gemba and watch. A short gemba walk is the right way to do it. Stand where you can see the person, tell them why you are there, and ask them to work as usual.
4. Draw one continuous line. Follow the person, part or vehicle and draw every move. Mark each stop with a dot and a short note, such as "gets torque tool". Use a new colour for each cycle or each person if you trace several.
5. Measure. Convert the line to distance with the scale on the plan. Count the trips per cycle or per shift. Time a few trips to get the time per trip.
6. Ask why for each knot. For every long or repeated line, ask why the trip is needed, and write the answer next to it.

Observe for a full cycle at least. For a job with long cycles, observe a full hour or shift. If the work changes through the day, such as at a shift start, draw a second diagram for that period.

Example: walking in a packing cell

This is an illustrative example, not a measured case. An operator in a packing cell makes three kinds of trips during a shift. The plan shows the round-trip distances and the team counts the trips:

• Tool crib: 24 trips, 70 metres per round trip, which is 1,680 metres.
• Material store: 40 trips, 45 metres per round trip, which is 1,800 metres.
• Inspection bench: 60 trips, 30 metres per round trip, which is 1,800 metres.

The total is 5,280 metres per shift. Assume the operator walks at 1 metre per second including stops, which is a planning figure you should check by timing your own trips. The walking then takes 5,280 seconds, or 88 minutes. In a 480-minute shift, that is about 18 per cent of the time.

The team asks why for each line and agrees three changes:

• Move the inspection bench next to the packing table: 5 metres per round trip.
• Kit the material for each order and deliver it to the cell once per hour: 10 trips of 45 metres.
• Give the tools a shadow board at the station: 10 metres per round trip.

The new distance is 60 × 5 + 10 × 45 + 24 × 10 = 300 + 450 + 240 = 990 metres. At the same speed, that is about 17 minutes. The saving is about 71 minutes per shift. The numbers are made up, but the method is the same in any plant: measure before, change, measure after.

LEI also reports a real case. At Thrustmaster of Texas, a Houston maker of marine propulsion equipment, a spaghetti chart of the assembly department showed technicians taking 110 steps per thruster and walking over seven miles, which LEI equates to nearly 10 hours wasted per unit. The team redesigned the assembly layout with a focus on flow, waste elimination and standard work. The article reports 100 per cent on-time delivery about 18 months later. It gives no figure for the cost savings. See the LEI story on the Thrustmaster spaghetti chart.

What to do with the diagram

A drawing alone changes nothing. Use it as a basis for decisions in four steps.

1. Read it. Look for four patterns: lines that cross, lines that double back, long lines for small items, and the same trip repeated many times.
2. Question each trip. Is it needed at all? Can it be done less often, by someone else, or at the point of use?
3. Choose a countermeasure. Typical ones, to optimize the layout and the process flow, are to move the store, bench or tool closer, to put tools and parts in a fixed place at the station, to bring material in kits or by a regular delivery round, and to change the layout so that the process steps follow the order of the work.
4. Test and draw again. Try the change with tape on the floor or cardboard mock-ups before you move heavy equipment. Then draw the diagram again. The second picture proves the gain, and it shows the next knot.

A spaghetti diagram shows physical movement. It does not show the flow of information or the waiting between steps, so combine it with process mapping or value stream mapping to see the whole workflow. If many lines lead to one bottleneck station, look there first, because inefficient movement around the bottleneck costs output for the whole line.

Walking waste is often a symptom of something else. A long walk to the tool crib may mean that the tools are missing at the station. A trip to the inspection bench may mean a quality check is in the wrong place. Follow the line to the cause.

Common mistakes

• Drawing from memory. An office drawing shows how people think they work. Draw at the gemba while you watch.
• Tracing too many people at once. Start with one role. Compare roles later.
• No numbers. A tangle looks bad, but management needs metres, trips and minutes.
• Blaming the walker. The layout and the supply of material cause the walking. The operator only follows them.
• Moving things before asking why. If you only move a bench, you may move the problem. Check why the trip exists.
• Stopping at one diagram. The first picture is a baseline. Draw one again after each change.

How software can help

A paper floor plan and a pen are enough for a first diagram. Digital floor plans and drawing tools can make a neat copy, and some plants record movements with simple tags or video to get more complete counts. For a larger layout change, simulation can compare options before any equipment is moved. Software shows the paths. It does not tell you why a trip exists, so the walk to the gemba stays necessary.

Next step

Print the floor plan of one area, pick one operator, and trace the path for one hour at the gemba. Then measure the distance and ask why for the three longest lines. That is a practical way to start with a spaghetti diagram.