A SIPOC diagram is a one-page, high-level map of a process showing its Suppliers, Inputs, Process steps, Outputs and Customers. It is used in the Define phase of a Six Sigma project to agree the scope before detailed work starts.
How to build a SIPOC
- Name the process and agree where it starts and stops.
- List the process in four to seven high-level steps.
- List the outputs and the customers who receive them.
- List the inputs needed and the suppliers who provide them.
- Add the customer requirements for the key outputs.
Example: purchase requisition to purchase order
- Suppliers: requesting department, budget owner, approved vendors
- Inputs: requisition, budget code, quotations
- Process: submit request, check budget, obtain quotations, approve, issue PO
- Outputs: approved purchase order
- Customers: requesting department, vendor, finance
Why SIPOC matters
It exposes scope disagreements early, shows hand-offs between departments and identifies who must be involved in the project. It is also a quick way to onboard new team members.
