SIPOC · finding the right process
Before you measure, you have to scope the process cleanly – otherwise you end up working on the wrong process. SIPOC (Supplier · Input · Process · Output · Customer) uses a bird's-eye view to find the steps where you suspect the causes of the problem (the big Y). The art is choosing the right altitude. Pick a case example and work through the nine phases – at the end you have your finished SIPOC diagram.
When do I need a SIPOC – and what for, exactly?
The most common question in the course. Here is the answer, using concrete everyday situations.
SIPOC is not a diagram for the filing cabinet. It is the tool for the moment when you are asked to improve a process but don't yet know exactly what everyone is actually talking about. In 60–90 minutes it creates a shared map – before anyone starts measuring or solving.
✓ What SIPOC is for
- Scope the process: where does it begin, where does it end?
- Get everyone involved to a shared view
- Make handovers and interfaces visible – that is where most problems arise
- Find measurement points: which outputs can be counted?
- Sharpen the assignment before time goes into data collection
✕ What SIPOC is not for
- Not a detailed flowchart – 4 to 7 steps are enough
- Not a root cause analysis – that comes afterwards (Ishikawa, data)
- Not a collection of solutions – whoever solves here skips the understanding
- Not a value stream – times and inventories do not belong in it
- Not an organisation chart – it is about flow, not hierarchy
In the Six Sigma sequence, SIPOC sits in the Define phase – before Measure. It is the first thing you do and rarely takes longer than half a day.
Pick a case – we'll work through it together
SIPOC at a glance
Five columns, one process in the middle. You read from the outside in – but fill it in from the inside out.
Who provides the inputs? A department, a system, a person.
What flows into the process and is consumed or processed?
The scoped steps – 4 to 7 – in which you suspect the causes.
What comes out? Including by-products: documentation, feedback, metrics.
Who receives the outputs? Internal recipients count too.
The goal is not a perfect flowchart but to scope the overall process in which the causes of the big Y lie. Every output needs a customer, every input needs a supplier. The idea behind it: Y = f(x) – the result is a function of the process steps.
Workshop – step by step
Nine phases. The panel shows what to do and why – below it you fill in the tool. All fields are editable.
Your SIPOC diagram
Builds up live from your entries. Dashed cards are the interfaces obtained with the predecessor/successor trick.
| SSupplierWho provides | IInputWhat goes in | PProcessProcess (scope) | OOutputResult | CCustomerWho receives |
|---|---|---|---|---|
Wrap-up: does your SIPOC hold up?
Check against the quality criteria – and what to do next.
Reflection & learning transfer
The real learning work – after filling it in.
1 · Where was the altitude decision hardest?
Most teams change the granularity at least once between phase 2 and phase 4. Was that the case for you too – and what prompted it: a team statement, choosing the scope, or defining the inputs/outputs?
2 · Which team statement revealed the most?
At least three statements point to causes outside your scope (e.g. code review or hardware procurement). Which ones were they – and do you actually need two or three parallel SIPOCs, or is one with clearly marked interfaces enough?
3 · How would the SIPOC change if the Y were different?
Suppose the real problem were not time but satisfaction after 90 days: which steps would drop out, which would be added? The exercise shows how closely the Y and the process are linked.
Video companion · Questions & answers
From the basic question “what for” to the finer points of scoping.
Key terms explained +
SIPOC scopes the process before it is measured and improved. Here are the most important terms in plain words:
How saving works +
This HTML file is your document. Everything you enter ends up in exactly this file when you save – just like a Word document. If you pass the file on, all SIPOCs in it go with it.
Save (green button or Ctrl+S) stores the current state – without any prompt. As long as no working file of your own has been created, the state is kept in the browser and is there again the next time you open it.
Save as (under “SIPOCs”) creates a file on your hard drive. This is the only place where you are asked where to save. After that, every further Save writes silently into exactly that file.
The first time: open the file, click “SIPOCs” and then Save as. From then on the green button is enough.
Saved automatically: as soon as a SIPOC has been saved once, the tool backs up every further change by itself after a few seconds.
If something goes wrong: the tool continuously keeps an interim state in the browser. If the browser crashes or you close the window by accident, your work is there again the next time you open it.
Note on browsers: writing directly to the file currently works in Chrome and Edge. In Firefox and Safari everything stays saved in the browser – the file itself remains unchanged.