Elements of Lean · Bonus lesson
What is SIPOC? Teach it to your child with a lemonade stall
SIPOC is a one-page map of a process, in five columns: Suppliers, Inputs, Process, Outputs, Customers. You draw it before you change anything, so everyone sees the whole picture first.
It takes fifteen minutes together at the kitchen table. Your child gets a way to break down a problem at school, and you get a way to see your work more clearly.
1 The idea in one minute
Start with a real stall. The Lean Heroes want to sell lemonade at the village fayre. Before anyone squeezes a lemon, they lay out five columns.
| Column | The question | At the stall |
|---|---|---|
| Suppliers | Who gives us what we need? | The corner shop, Grandma's lemon tree, the fayre committee |
| Inputs | What do we need? | Lemons, sugar, ice, cups, a cash tin with change |
| Process | What are the main steps? | Squeeze and mix, pour and sell, tidy up |
| Outputs | What comes out? | Cups of lemonade, money for the dojo |
| Customers | Who gets it? | The vicar, the footballers, Mrs Jones from the cake stall |
That's all SIPOC is. It doesn't fix anything on its own. It shows you where the process starts, where it ends, and who is involved. Then you spot problems early: no cups packed, or nobody planning to tidy up.
Some things matter but don't go in a column. Sunny weather isn't a supplier: it changes how many customers come. Someone tasting the stock isn't a process step: it's waste.
2 Where it fits
SIPOC isn't in the first Lean Heroes book. It fits just before the first step of DMAIC.
In The Lean Heroes and the Dinner Disaster, Lauren the Owl starts the Define step by writing the problem in one sentence. A SIPOC is the picture around that sentence.
In the game, the stall's problems lead to DMAIC too. Your child picks one problem and sees how Define, Measure, Analyse, Improve and Control would fix it.
3 Teach it tonight (15 minutes)
You need: a sheet of paper, a pen, and tomorrow's breakfast.
- 2 minutes. Play the first stage of the game together, or just read the lemonade table above.
- 3 minutes. Draw five columns. Write S, I, P, O, C at the top. Say what each letter asks, using the table.
- 5 minutes. Fill it in for breakfast. Let your child do the writing. Who supplies the bread and milk? What goes in? What are the steps? What comes out? Who eats it?
- 3 minutes. Hunt for one thing that goes wrong at breakfast. Is something missing from Inputs, like no milk? Is a step missing from Process, like nobody clearing the table?
- 2 minutes. Pin the sheet on the fridge. Tomorrow morning, check it against what really happens.
If your child gets stuck, go back to the stall. Concrete first, names second.
4 The Feynman check
Can you explain the five letters to your child using your own kitchen? Then you've got it.
Try these three without looking:
- What does each letter of SIPOC stand for, and what question does it ask?
- Why is "sunny weather" not a supplier?
- Why do you draw a SIPOC before trying to fix anything?
Where you get stuck is the bit to read again. That's the useful part.
5 Next step
Next, pick one real problem from your breakfast SIPOC and write it in one sentence. That's the Define step.
One idea to keep from the book. It ends with the Lean Hero Pledge: I will never blame a person when I can fix a process.
A SIPOC helps, because it looks at the whole process, not at who got it wrong.
If your child liked this, the Lean Heroes book has the whole story. Find out about the book.
This lesson teaches the basics and the thinking. It is not a replacement for a professional Lean Six Sigma Belt course.