SIPOC Process
Make the process boundaries, hand-offs and customer requirements visible.
Live SIPOC map
Each interface row connects a supplier and input to process steps, an output, and the customer who needs it.
High-level process steps
Use roughly 5–7 meaningful steps. This is a process overview; keep detailed instructions in controlled documents. Link interfaces using the step IDs.
Supplier-to-customer interfaces
Actions & process controls
Give each action an owner, due date and objective evidence. Completion and effectiveness are separate decisions.
Performance against target
A trend chart supports review. It is not an SPC control chart; target lines are not statistical control limits.
Review & closure
The readiness check flags missing records. The reviewer must judge the quality and adequacy of the evidence.
Define the process before improving it
SIPOC gives a high-level view of a process and its boundaries. Suppliers provide inputs; process activities transform them into outputs; customers receive and use those outputs. Suppliers and customers can be internal or external.
Who provides what the process needs?
What enters, and what quality is required?
Which high-level activities transform inputs?
What leaves, and what defines acceptance?
Who uses the output, and what do they need?
Build a reliable SIPOC
- Agree the process purpose, start trigger and end point. Identify the owner and exclusions.
- Observe the current process with the people who do the work. Describe roughly 5–7 high-level steps in sequence.
- Identify outputs and customers, then the inputs and suppliers needed to create those outputs.
- Connect each interface and define acceptance requirements, customer needs and critical-to-quality (CTQ) measures.
- Check the map with suppliers, practitioners and customers. Confirm hand-offs, exceptions and missing interfaces.
- Use the map to prioritise investigation and establish detailed process controls.
SIPOC is a starting point for control
A SIPOC describes the process at a high level. It does not show every decision, loop, failure mode or work instruction. Extend it with process flow, PFMEA, a control plan or a turtle diagram where needed.
For each important input and output, specify the acceptance criterion, measurement method, frequency, owner, record and reaction to failure. Verify measurement suitability and competence. For special processes, consider validation and periodic testing when final inspection cannot fully verify the result.
Define customer needs as measurable requirements
Translate “good quality” or “fast delivery” into specific requirements: permitted defect rate, traceability content, agreed turnaround or required documentation. Identify the source and revision. CTQs should represent important customer needs, with suitable evidence and a consistent denominator.
Specification limits define acceptance; statistical control limits describe process behaviour. A trend meeting a target once does not demonstrate sustained effectiveness.
Common mapping errors
- Confusing an output with an activity, or a customer with the process owner.
- Listing suppliers without identifying the inputs they provide.
- Omitting information, approvals, software or documents from the inputs.
- Mapping an ideal future process as if it were the current process.
- Ignoring quarantine, rework, missing documents and rejected outputs.
- Using a SIPOC as authority to release nonconforming material.
Worked example: goods-in acceptance
The fictional example starts when a supplier delivery arrives and ends when material is accepted into stock or placed on hold with a nonconformance record. A supplier provides product and certification; Engineering provides drawing requirements; Procurement provides the purchase order. Stores and Production receive accepted material; Supplier Quality receives NCRs for unresolved issues.
The pilot improves first-pass acceptance from 82% to at least 95%, using a standard document check and clearer supplier flowdown. The map includes the rejected-material branch so “material received” is never assumed to mean “material accepted”.