A Spaghetti Diagram traces movement through a workspace so teams can see wasted motion, travel distance, crossing paths, and layout problems.
Definition
A Spaghetti Diagram is a visual map of the actual movement of people, materials, information, tools, or products through a process area. Lines drawn over a layout often look tangled, revealing wasted travel, poor layout, repeated searching, and unsafe crossing paths.
It is most useful when built from direct observation rather than assumptions.
History
Spaghetti diagrams grew from industrial engineering, motion study, and Lean waste observation. They became common in Kaizen events because motion and transport waste are easier to understand when teams see the path physically traced.
When to Use
Use a Spaghetti Diagram when people walk excessively, materials travel far, layouts feel confusing, handoffs are scattered, ergonomic strain is high, or work areas need redesign.
Step-by-Step
- Get or sketch an accurate layout.
- Define what movement will be tracked and for what period.
- Observe real work without directing it.
- Trace each movement path and note purpose, distance, and frequency.
- Mark delays, searches, crossings, and safety concerns.
- Quantify travel distance or time if useful.
- Redesign layout, point-of-use storage, flow, or handoff rules.
- Repeat the diagram after changes to verify improvement.
Examples
- Assembly: Operators walk repeatedly to shared tools and parts racks.
- Lab: Samples cross paths between receiving, prep, and testing.
- Office: Paper files move between several desks before approval.
Common Pitfalls
- Drawing the ideal route instead of observed movement.
- Ignoring frequency and reason for trips.
- No scale or distance estimate when travel reduction is the goal.
- Redesigning layout without worker input.
- Improving motion while creating safety or ergonomic issues.
- No follow-up measurement after layout changes.