A3 refers to standardized communication format, a disciplined process of expressing complex thoughts accurately on a single sheet of paper. A3 is a standardized technical writing methodology to create a report on one side of a standard size piece of paper to guide problem solving and achieve clear communication across functional specialties. There are four types of different A3 forms:

1. Proposal story. Used for proposing a plan or new initiative, this story always revolves around a theme. Although it does not end with an actual proposal, it requires a clear plan, identification of issues that will have to be resolved, and a schedule.
2. Status story. Used for giving the status of an ongoing initiative, this story calls for actionable information. What was the objective of the project and how is it going relative to the objective? What was the planned versus actual implementation time line? What issues need to be resolved, and what future actions are planned?
3. Informational story. Used to share information, for example, about a development at a competing company or elsewhere in Toyota, informational A3s are “free-form” and the layout and delivery of the story is left to the writer to formulate.
4. Problem solving story. Used when a plan, goal, or standard exists and the company is not meeting it. That is, there must be a problem. The problem-sovling story needs to be thorough, communicating the complete process of plan-do-check-action. Embedded in this storytelling is Toyota’s approach to “practical problem solving”, making clear the goal, the data on the current situation, a detailed analysis of the root cause, countermeasures, and the story of implementation. The follow-up must include the verification (check) that the countermeasure worked, future actions to use, and what was learned in the verification process. An example of a problem-solving story for a safety issue is shown below.

In A3 reporting, the point is to have high value-added documents in which it is easy to see the critical points unimpaired by waste – too many words, elaborate explanations, graphs, etc.Muda in documents obscures the message and often causes people to leave out key points.

Source: Liker, J.K and Morgan, J.M, The Toyota Product Development System: Integrating People, Process and Technology, Productivity Press, 2006