What Is An A3 In Lean?

What Is an A3 in Lean?

Welcome to the blog! Today, we’re diving into a powerful Lean tool that helps teams make clear, effective decisions: the A3. I’ll walk you through an example we recently used on one of our Lean-built projects and show you how this format can simplify your work and improve outcomes.

So what exactly is an A3? At its core, it’s simply a paper size—sounds silly, right? But the idea is profound. Instead of relying on hundreds of pages or scattered documents, the A3 format allows you to tell a complete story on one page. It’s a seeing tool—because in Lean, if you can’t see it, it’s not Lean yet.

In this blog, I’ll also reference page 257 of the Elevating Pre-construction Planning book, where the A3 concept is discussed in detail. We’ll go through the structure and format we use and show you how you can apply it in your own work to tackle big issues with clear, collaborative decision-making.

The Power of One Page:

You don’t have to stick to 8.5×11—you can use 11×17, 18×24, even 36×48. The size isn’t the point. What matters is: Can everything be shown on one page in a way that helps your team understand the problem, align on goals, and make a decision?

Patrick Lencioni said that if you can get an organization rowing in the same direction, you can dominate any industry, anytime. The A3 helps us do exactly that. It’s used primarily for problem evaluation, but also works well for:

• Integrated Project Delivery (IPD) efforts.
• Business and design decisions.
• Strategic planning.
• Scheduling.
• Complex project issues.

Key Elements of an A3:

Here’s the typical structure of an A3:

1. Problem Statement.
2. Current State Analysis – Gives essential background and context.
3. Goal – What are we trying to accomplish?
4. Root Cause – The most critical element; understanding why the problem exists.
5. Proposed Countermeasures – Options to address the root cause.
6. Plan of Action – Once a path is chosen, lay out the next steps.
7. Follow-up & Evaluation – Don’t let the effort die—track results and close the loop.
8. Reflection & Learning – What did we learn, and how can we improve?

Real Project Example: Switchgear Decision:

Let me walk you through a real A3 we created for a switchgear procurement issue. This was not an easy process—we had to weigh multiple options:

• Wait for APS approval.
• Order immediately through a trade partner.
• Order through a wholesaler.

We built out the A3 by including:

• Root cause and current state analysis.
• A side-by-side comparison of the options.
• Timelines and pros/cons for each.
• Clear visuals to support decision-making.

Although “choosing by advantages” typically avoids listing cons, in this case, we needed the owner to fully understand the risks. With everything laid out on one page, they were able to quickly select option three—no back and forth, no delays, just clear action. Today, we’re executing that decision on our project with great results.

Why A3s Matter:

This tool helped us tell a complete story, anticipate objections, and prepare the team. By the time we presented it to the owner, they were able to evaluate and act without confusion or delay. That’s the power of a well-crafted A3.

We need to use this tool more in construction. Not as a criticism of our industry, but as a way forward—because Lean tools are all about seeing, understanding, and acting together.