Major Cause Categories Include the 4 major cause categories (use boxes): 1) Method, 2) Material, 3) Manpower, 4) Machine. Cause Categories Include at least 3 Cause Categories (parallel arrows) for each Major Cause Categories. A total of 12 Cause categories. Sub-Causes Include at least 3 Sub-Causes for each Cause Category (at least 9 sub-causes for each Major Cause Category). A total of 36 Sub-Causes. Distinction Ensure that Major Cause Categories, Cause Categories, and Sub-Causes are clearly distinguished by symbols (box, circle, arrows, etc.), or by color/font