Definition
Trace the walking and transport paths of people or materials on the actual layout to identify back-and-forth movement, crossings, and unnecessary movement.
In detail
A spaghetti diagram uses the shop-floor layout as its base map and records the actual paths taken by people or materials through observation, noting distance, frequency, and time where necessary. It shows physical movement, differs from a flowchart that describes step sequence, and cannot replace a value stream map that simultaneously analyzes information flow and time. Before drawing, the tracking subject, observation window, and work type should be stated; after improvement, re-measure using the same basis.
Example in practice
During changeover, an observer followed the operator and recorded the route for finding tools, retrieving dies, and returning to the equipment, discovering multiple trips across workshops. The team moved frequently used items to the point of use and adjusted the preparation sequence, then measured the path and time for the same type of changeover, avoiding drawing only a nice-looking layout diagram.