SIPOC is a high-level process-scoping tool used to identify the Suppliers, Inputs, Process, Outputs and Customers of a process. It is especially useful at the beginning of a process-improvement exercise because it establishes a common view of what the process includes before the team creates a detailed flowchart.
ASQ describes SIPOC as a tool used by Six Sigma process-improvement teams to capture the relevant elements of a process and recommends using it as a high-level view of the current state before building a detailed flowchart.
What Does SIPOC Stand For?
| Element | Question | Example |
|---|---|---|
| Suppliers | Who or what provides the inputs? | Vendor, requester, carrier, master-data team |
| Inputs | What is required for the process to work? | Purchase requisition, specification, PO, delivery document |
| Process | What are the major 5–7 activities? | Approve → order → receive → invoice → pay |
| Outputs | What does the process produce? | Received goods, approved invoice, payment, updated inventory |
| Customers | Who uses or depends on the output? | Operations, warehouse, finance, end customer |
When to Use SIPOC
- At the beginning of a process-improvement project.
- When different departments disagree about where the process starts or ends.
- Before creating a detailed process map.
- When defining project scope for Lean Six Sigma or other improvement work.
- When identifying key suppliers, customers, inputs and outputs.
- When a process has many cross-functional handoffs and the team needs a common high-level view.
How to Build a SIPOC
- Define the process name and boundary. Agree exactly where the process starts and ends.
- Write the high-level process. Keep it to roughly five to seven major activities rather than detailed work instructions.
- Identify the outputs. What product, service, information or decision does the process create?
- Identify the customers. Who receives or depends on each output?
- Identify the inputs. What information, materials, approvals or resources are needed?
- Identify the suppliers. Who provides each important input?
- Validate with the process team. Confirm that the SIPOC reflects the actual current process.
Many teams build SIPOC from the centre outward: define the process first, then outputs and customers, followed by inputs and suppliers. This prevents the exercise becoming an unstructured list of stakeholders.
Procure-to-Pay SIPOC Example
| Suppliers | Inputs | Process | Outputs | Customers |
|---|---|---|---|---|
| Requester, supplier, procurement, master-data team | Requirement, approved supplier, price/contract, budget, specification | Request → Approve → Order → Receive → Invoice/Match → Pay | Purchase order, received goods/service, approved invoice, supplier payment | Requester, operations, warehouse, finance, supplier |
This is intentionally high level. If the objective is to investigate long invoice cycle times, the next step would be a detailed process map showing PR approval, PO creation, receipt posting, invoice matching and exception handling.
Warehouse Receiving SIPOC Example
| Suppliers | Inputs | Process | Outputs | Customers |
|---|---|---|---|---|
| Supplier, carrier, purchasing | PO, ASN/delivery note, goods, specification | Arrive → Unload → Count → Inspect → Receive → Put Away | Accepted stock, receipt record, discrepancy report, quarantined stock | Inventory control, operations, finance, procurement |
SIPOC vs Detailed Process Map
| SIPOC | Detailed Process Map |
|---|---|
| High-level scope | Step-by-step workflow |
| Shows key suppliers, inputs, outputs and customers | Shows activities, decisions, handoffs, systems and exceptions |
| Usually created early | Usually created after the boundary is understood |
| Good for alignment | Good for diagnosing delay, waste and control gaps |
What Is SIPOC+CM?
ASQ also describes an expanded version called SIPOC+CM:
- C = Constraints: limits or conditions that restrict the process, such as capacity, policy, regulation, system limitations or lead time.
- M = Measures: the metrics used to evaluate the process, such as cycle time, service level, error rate, cost or OTIF.
This is useful when the team wants to connect the high-level process definition immediately to performance and operating limitations.
Questions to Ask in a SIPOC Workshop
- Where exactly does this process start and end?
- What are the major activities—not every detailed task?
- What outputs must the process reliably produce?
- Who receives those outputs?
- What requirements do those customers have?
- What inputs are critical to producing the output?
- Who provides those inputs?
- Which constraints or regulations affect the process?
- How do we measure whether the process is working?
Common SIPOC Mistakes
- Turning the process column into a detailed 30-step flowchart.
- Confusing suppliers with customers.
- Listing departments without identifying the actual input or output they provide.
- Using the desired future process instead of the current-state process under investigation.
- Failing to define start and end boundaries.
- Ignoring internal customers.
- Creating the SIPOC alone instead of validating it with the people who perform the process.
Interview Question: What Is SIPOC Used For?
A strong answer is: SIPOC is a high-level process-scoping tool that identifies the suppliers, inputs, major process steps, outputs and customers. I would use it early in an improvement exercise to align stakeholders on the process boundary before building a detailed flowchart or analysing failure modes.
Related SCMANA Guides
Reference
American Society for Quality (ASQ), SIPOC+CM Diagram.
Download the Practical Workbook
Use the SCMANA SIPOC + Constraints & Measures Template to define suppliers, inputs, process steps, outputs, customers, constraints and performance measures.
Download the SIPOC + Constraints & Measures Template (Excel)
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