One problem on one page

In Lean: A3 problem solving

Understand first, then act

Read it from the top left to the bottom right. Each box should follow from the one before it.

Who and when

Written by

Talked through with

Draft date

Background

Why does this problem deserve attention now, and who does it affect?

Two or three lines a reader needs before the facts.

The problem (in Lean: problem statement)

Facts someone could check. No cause, no fix and no names: name the step, not the person.

What should happen?

The expected result. This is your target.

What actually happens?

What you saw or counted, not what you remember.

Where and how often?

Which team, which kind of item, which days.

Why does it matter, and to whom?

What happens today (in Lean: current state)

Follow one or more real items and note each step as it really happened.

Step	Who does it, in which tool	Working timeSomeone is working on it.	Waiting timeIt sits before the next step.

Where does the work wait or go wrong?

Why does it happen? (in Lean: 5 Whys, short)

Each answer is a fact someone checked. Stop at a process, a policy, a tool or an owner, never a person.

Why	Because...	How do we know?
1
2
3
4

What is the cause you can change?

Should this step exist? (in Lean: eliminate before you improve or automate)

Test the step the cause sits in: who uses what it produces, what would happen if it stopped, has it ever changed the outcome, and what really requires it?

Which step does the cause sit in?

Should this step exist?

Tick one.

No, remove this step.
Yes, keep this step.

What is the reason?

Who uses its output, and which real rule requires it, if any.

Which is the first option on this list that answers the cause?

Go down from the top and stop at the first one that works. If the step should not exist, it is the first. Tick one.

Remove the step In Lean: eliminate.
Join two steps into one In Lean: combine.
Change the order, the timing or who does it In Lean: rearrange.
Make what stays lighter In Lean: simplify.
Then automate what is left Only once the step is as small as it can be.

What will change (in Lean: countermeasure)

Each change answers a cause on this page, concretely enough that someone else could put it in place.

What will change	Which cause it answers	Who	By when

Is a quick patch needed until then, and when does it end?

In Lean: containment. Without an end date it becomes permanent extra work.

Check: did it hold? (in Lean: check, in PDCA)

Agree this before the change starts. Use the measure you already have; if you have no number, name something you can see in the work.

What will you look at, and which result would show it did not hold?

Check-ins

Look at the work itself at each date. Answer held, partly or reverted, as things really are.

When	Date	Did it hold?held / partly / reverted	What did you see in the work?
Day 7
Day 14
Day 30