What SIPOC is
A SIPOC is a one-page diagram that shows a process end to end: who supplies it (Suppliers), what goes in (Inputs), the main steps (Process), what comes out (Outputs) and who receives it (Customers). It aligns the team on the boundaries of the process before any detailed analysis.
SIPOC visual map
The map shows what each letter means, the plastic injection molding example and how SIPOC compares with a flowchart and a VSM.
What each letter means
| Letter | Stands for | Question |
|---|---|---|
| S | Suppliers | Who provides the inputs? |
| I | Inputs | What does the process need? |
| P | Process | What are the 4 to 7 main steps? |
| O | Outputs | What does the process produce? |
| C | Customers | Who receives the outputs? |
Example: plastic injection molding
| Suppliers | Inputs | Process | Outputs | Customers |
|---|---|---|---|---|
| Resin supplier Tool room Production planning | Resin Mold Production order | Dry the resin Prepare the machine Inject Inspect Package | Approved parts Production record | Assembly End customer |
How to build it
- Start with the process, in 4 to 7 high-level steps.
- Define the outputs of the process.
- Identify the customers, internal and external.
- Identify the inputs required.
- List the suppliers of each input.
Starting with the P keeps the team from debating details too early. Some teams start from the customer and call it COPIS; the result is the same.
When to use it
- In the Define phase of DMAIC, to set the project scope.
- At the start of improvement projects and A3 reports.
- To explain a process to newcomers.
- To bring together teams from different departments.
SIPOC, flowchart and VSM
| Tool | Level | Shows |
|---|---|---|
| SIPOC | High level, one page | Boundaries, suppliers, inputs, outputs and customers |
| Flowchart | Detailed | Every activity, decision and path |
| VSM | Value stream | Times, inventory and waste from order to delivery |
A common sequence is SIPOC for scope, a flowchart for detail and a value stream map to see lead time and waste.
Common mistakes
- Leaving important steps out, or detailing the process too much.
- Confusing inputs with outputs.
- Not involving the right areas.
- Using vague or generic terms.
Frequently asked questions
What is a SIPOC diagram?
A one-page diagram showing a process's suppliers, inputs, process steps, outputs and customers.
What does SIPOC stand for?
Suppliers, Inputs, Process, Outputs and Customers.
How many steps should the process column have?
Between 4 and 7 high-level steps.
When should SIPOC be used?
Mainly in the Define phase of DMAIC and at the start of improvement projects, to set the scope.
How does SIPOC differ from a VSM?
SIPOC shows process boundaries at a high level; a VSM shows the value stream with times, inventory and waste.
Sources
- GEORGE, M. L. et al. The Lean Six Sigma Pocket Toolbook. New York: McGraw-Hill.
- PYZDEK, T.; KELLER, P. The Six Sigma Handbook. New York: McGraw-Hill.
- TAGUE, N. R. The Quality Toolbox. Milwaukee: ASQ Quality Press.
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About the author
Lean Manufacturing & Behavioral Management Specialist
Over 20 years in the automotive and metalworking industries (GM and Dana), Lean Manufacturing practitioner since 2006. SENAI instructor and mentor in Brazil’s Brasil Mais Produtivo program, delivering consulting, training and audits for 50+ companies, combining quality, productivity and people development.