DRIVING QUESTION
What does material actually do in this building, before I draw any equipment?
Read the flow against the floor. Draw the story before you place a single machine.
Layout vs Design
A Layout
Equipment on a floor plan. Starts from the hardware. Looks finished, skips the thinking underneath.
A Design
The logical movement of material, worked out before any machine gets a name. Starts from the flow.
Process Flow Diagram Checklist
- Every entry point shown
- Every exit point shown
- Every decision point marked
- Every split and merge shown
- Every wait point marked
- Replenishment and returns as distinct flows
- Reads out loud as a complete story
- Assumptions labeled safe or unsafe
DESIGN PRINCIPLE
Flow before equipment.
If the flow is wrong, so is every layout built on top of it, and no equipment corrects a flow problem after the fact.