What is a spaghetti diagram?
A spaghetti diagram (also called a spaghetti chart or physical process map) records the actual route taken by a worker, a product or a document through a workplace. It is one of the simplest and most persuasive lean tools: once the lines are drawn, the back-and-forth trips, long walks to shared equipment and crossing flows are impossible to ignore.
How to make a spaghetti diagram
- Observe at the gemba. Follow one person or one part through a full cycle, noting every stop.
- Draw the layout to scale: workstations, storage, offices, doors.
- Trace every movement in order, including returns and detours.
- Measure the distance and multiply by the number of cycles per day.
- Redesign the layout or method to shorten and straighten the flow, and measure again.
Spaghetti diagram example
The example follows parts through a bracket fabrication cell with nine stations. The current material flow makes 12 moves per batch, going back to the raw store, the QC lab and assembly several times: about 168 m per trip, or roughly 1 km a day at six batches. The proposed flow removes the returns by bringing in-process checks to the line, cutting the route to 7 moves and about 64 m per trip, a reduction of more than 60%.
Ideas to reduce motion and transport
- Place workstations in process sequence, ideally in a U-shaped cell.
- Bring materials, tools and gauges to the point of use (5S, shadow boards, kanban).
- Move inspection into the line instead of sending parts to a remote lab.
- Combine trips with fixed-route material handling ("water spider").
Quantify the whole flow, including inventory and waiting, with value stream mapping.
How to use this Spaghetti Diagram tool
- Set the area size. Enter the real width and depth of the area in metres, or upload a floor plan image.
- Place the stations. Add stations for each workstation, storage area or point of use, and drag them to their real positions.
- Record a route. Add a route, then click the stations in the order the person or material visits them, including every return trip.
- Add trips per day. Enter how many times per day the route is travelled to get the daily distance.
- Design a better layout. Add a second route for the proposed path, or move stations, and compare distances.
- Export. Export the diagram and distance tables to PDF, PNG or Excel for your kaizen or layout proposal.
Frequently asked questions
What is a spaghetti diagram?
A spaghetti diagram is a lean tool that traces the actual path of a person, product or document through a workspace. Drawn on a floor plan, the lines often look like a plate of spaghetti, making wasted motion and transport visible.
What waste does a spaghetti diagram reveal?
It reveals two of the eight lean wastes directly, transportation (moving material) and motion (people walking or reaching), and often points to others such as waiting and over-processing caused by a poor layout.
How do I measure distance on a spaghetti diagram?
Set the real width and depth of the area, place the stations in their actual positions, and record the route. The tool calculates the straight-line distance between consecutive stops, per trip and per day based on trips per day.
Can I use my own floor plan?
Yes. Upload an image of your floor plan or a photo of a sketch, set its real width in metres, then drag the stations onto it. The image is stored only in your browser.
How do I compare the current and future layout?
Add a route for the current path and another for the proposed path or layout. The legend and table show distance per trip and per day for each, so the saving is clear.
Is the spaghetti diagram tool free?
Yes. It is free, needs no sign-up and keeps your data in your browser. Export to PDF, PNG, Excel or CSV, or save a file to continue later.