Flowchart vs Schematic Transit Diagram
フローチャート / スキーマティック路線図
Flowchart comes from Diagrammatic Expression and Schematic Transit Diagram from Information Design. Both are read here as layout. They are reached for with some of the same intent, which is where they get confused.
Flowchart
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The Gilbreths invented this process diagram for work analysis. Its grammar of shapes gives a diamond to every decision and a rectangle to every process, and by way of programming it became the common language for thinking in steps.
Schematic Transit Diagram
Discards geographic accuracy for horizontal, vertical and 45-degree lines with evenly spaced stations. Beck's 1933 London Underground diagram established it as the common language of transit maps worldwide.
| Flowchart | Schematic Transit Diagram | |
|---|---|---|
| Era | 1921– | 1933– |
| Family | Diagrammatic Expression | Information Design |
| Kind | Layout | Layout |
| Cues | A grammar of shapes / The decision diamond / Arrows of flow / Start and end terminals | Lines limited to 45 degrees / Evenly spaced stations / Color-coded lines / Independence from geography |
| Best used for | Getting a team to agree on a work procedure that branches · Surfacing branches and exceptions in a spec before implementation | Reducing a complex network to what riders need, stations and interchanges · Showing a process or line where order matters more than geography |
| Type | A question inside every diamond, a verb first sentence in rectangles | Set station names at one constant angle in a single face and size |
| Composition | Main path down one column, branches right and always rejoining | Only horizontal, vertical and 45 degrees, even spacing, widened where stations crowd |
| Material | Each branch labeled with its answer, terminals only at both ends | One color per line, white circles for interchanges, plain background behind |
| Caution | Mixing diamonds and rectangles without respecting their meanings erases the line between decision and process, and readers guess. | Trying to keep a little geographic accuracy breaks the angle rule, and the diagram ends up neither accurate nor easy to read. |