A3 problem solving is a structured problem-solving approach used in lean manufacturing. It involves documenting problems, solutions, and plans on an A3-sized paper (11x17 inches). The approach was created by Toyota to clearly communicate solutions in a single page report. The A3 process involves 10 steps including defining the issue, analyzing root causes, setting goals, developing countermeasures, and conducting tests and follow ups. Benefits include quicker problem solving, a consistent organization-wide approach, and facilitating communication to build consensus.