ASSUMPTIONS AND THEIR ROLE IN COSTLY MISTAKES – PART 3

Fool proof systems never work; sometimes I am driven to this conclusion. See the

following story.

     The Factory had a type of special type of component which should be used for ‘Severe Service’. The only difference between the one which is used for ‘Normal Service’ is a special coating on the surface of the component. The order was for a special severe/service product, the marketing people conveyed to design department. Design department issued a special Bill of materials (BOM) suiting that. This BOM went to the planning department. When the planning Engineer raised the indent (manually prepared Purchase requisition) for the items, the wrong item was requested, the one without coating . The Purchase Order was made out of the wrong item and it went for technical approval(vetting) to Design department. The error was overlooked by the design department. The Purchase Order  was released for the wrong item. There was delay in supply of the item from the supplier. Everybody was following up that item. As soon as it arrived, the item was inspected as per Purchase Order(as it was for “without coating”), used in the assembly and then went for testing.

    The product withstood to the ‘Severe’ stage and final testing, later it got installed at the customer’s project(may be a case of factor of safety).

    How did this get exposed that the wrong items went into the product?

     Later there was a similar order for another customer. Again wrong items got ordered. That day, the line supervisor for the assembly was on leave and another supervisor was officiating for him.

     The new supervisor checked the items as per specifications required and found that it was in variance from the BOM. He raised the alarm. Then QA checked the previous order, just in case . The error was identified only then.

     What is the root cause here? In how many places did ‘ASSUMPTION’ wreak its havoc?