A3 problem solving or A3 thinking is a structured problem solving approach based on a rigorous Plan-Do-Check-Act (PDCA) cycle. A3 thinking and A3 reports were popularized by Toyota and are considered Lean tools.
The term “A3″ in this tool’s name is linked to the original paper size used for the report, which was the largest paper sheet a fax machine could handle, the DIN A3 (297 x 420 mm), metric equivalent to 11″ x 17” (or B-sized).
Too often people facing a problem rush to solutions without gathering data and spending enough time analyzing the facts. This may kill an undesirable effect or symptom, but not the problem’s root cause, allowing the problem to surface again later, elsewhere or in a different form.
A3 problem solving “forces” people to structure their problem solving approach and stick to the four PDCA steps:
- Plan means gathering data and facts about the problem in order to state it properly and completely, going to the gemba (the actual place). Using is/is not discrimination is a good way to set the problem’s boundaries. Plan is also about analyzing the problem, data and facts to state an hypothesis about the root cause and how to address it.
- Do is conducting trials (experiments) to solve the problem with one or a limited number of solutions.
- Check means evaluating the results; does the proposed solution solve the problem? What are the figures before/after? The check should be conducted over a significant period of time to ensure the robustness of the solution and/or consistency of measurements over time.
- Act will either lead to discard the solution that failed and try another one or set the solution as a standard, e.g. adjusting parameter value, changing the process steps, etc.
A3 thinking with its structured and formal statement-trial-evaluation is quoted scientific method.
To help problem solvers to stick to the formal way, the A3 report format guides users through the solving process.
An A3 is still based on a A3 or B-sized paper sheet* which has four to seven or more boxes, according to the templates.
Each box is to be filled accordingly to the requirements.
A3 could/can be sent by fax, allowing distant participants to join the problem solving or get feedback. Nowadays a snapshot with a smartphone may be easier and faster way to share.
A3 reports are knowledge bases and should be kept and archived once problem solved as a similar one may appear in future.
A3 reports are also a tool to help people learn how to solve problems, especially useful for shop floor staff.
*A3 are operational tools, they must be fit to be filled in the workshop, on the gemba, over a machine case or a crate. A3s can be pinned to a wall for communication purpose. Filling A3’s on a computer or retyping a paper A3 content into an electronic file is considered a muda, pure waste. If you need to keep trace or file it, take a picture.