A3 is a structured problem solving and continuous improvement approach, first employed at Toyota and typically used by lean manufacturing practitioners. It provides a simple and strict approach systematically leading towards problem solving over structured approaches. A3 leads towards problem solving over the structure, placed on an ISO - ISO A3 single sheet paper. This is where the process got its name. A3 is also known as SPS, which stands for "Systematic Problem Solving". The process is based on the principles of Deming's PDCA (Plan-Do-Check-Act).