Why did the machine stop? (There was an overload and the fuse blew.) 2. Why was there an overload? (The bearing was not sufficiently lubricated.) 3. Why was it not lubricated sufficiently? (The lubrication pump was not pumping sufficiently.) 4. Why was it not pumping sufficiently? (The shaft of the pump was worn and rattling.) 5. Why was the shaft worn out? (There was no strainer attached and metal scrap got in.)
