The True Cost of Defects
Time, Confusion and Hidden Costs Add Up Quickly
A seemingly innocuous defect is traced through the manufacturing process at a window plant. At each point, the costs of wasted time and material are calculated. This example illustrates the hidden costs of poor quality and the Cost of Confusion that results.
Original Cost of Error.. $135.00 Final Cost Of Error.... $2673.31
| # | Description | Cost |
| 1 | The extrusion department makes 100 pounds of C-80019 extrusion that is defective. One flange is bent slightly inward. The defect is not detected. At this point, the extrusion has cost $1.16/lb. | 116.00 |
| 2 | The extrusion moves through several additional processes including paint. It is stored, handled, and records are kept. The additional cost is $0.19/lb. | 19.00 |
| 3 | An operator sets up a punch press to notch the ends. The setup requires 0.5 Hours @ $11.75/Hr. | 5.88 |
| 4 | An operator attempts to notch the extrusions. The bent flange prevents entry into the punch die. The operator calls for a supervisor and waits for 15 minutes. Operator cost is $11.75/hour. | 2.94 |
| 5 | Supervisor arrives. Operator and supervisor attempt to process the parts without success. Supervisor calls Diemaker. Both wait for arrival of diemaker. Total time is 20 minutes. Supervisor's time costs $14.75/hour. | 8.75 |
| 6 | Supervisor, Operator, and Diemaker discuss the problem and attempt to process without success. They decide to grind out the die so the extrusion with the bent flange will fit into it. All three work to remove the die and take it to the die shop. Total time required is 1.0 Hours. Diemaker's cost is $13.50/hour. | 40.00 |
| 7 | Diemaker grinds out die, returns to press and sets up the press. Total time 3.4 hrs. | 45.90 |
| 8 | Diemaker, Operator, and Supervisor assemble to determine status. The operation seems to work. Diemaker and Supervisor go on to other activities, Operator prepares to process parts. Total time required 17.0 minutes. | 11.33 |
| 8A | Scheduler spends 1.5 Hrs @ $15.75/Hr to change schedule and advise customers of change. | 23.63 |
| 9 | Operator processes parts and carries them to the Assembly department. Total time for the lot of 100-lb of parts is 50.0 minutes. | 9.79 |
| 10 | Assembly builds windows with the defective parts. Many windows do not operate properly because of the bent flange. Assemblers expend 4.2 extra man-hrs attempting to make the windows operate. Assembler time costs $10.50/hr. | 44.10 |
| 11 | An Inspector notices that some windows are difficult to operate. She confers with Assembler for 15.0 minutes and decides to summon the inspection supervisor. Inspector rate is $12.75/Hr and Inspection Supervisor is $17.25/Hr. | 5.81 |
| 12 | The Inspection Supervisor arrives and the Assembly Supervisor comes to see what the problem is. Four persons meet on this problem for 13.0 minutes and decide to summon the Engineer. All wait for an additional 11.0 minutes until the Engineer arrives. | 21.28 |
| 13 | The Engineer, Inspection Supervisor,Assembly Supervisor, Assembler, and Inspector confer for 25.0 minutes and determine a way to fix the problem. All then depart to other activities. The Engineer's time costs $26.75/Hr. | 34.27 |
| 13A | Inspector Documents events-- 25 minutes. | 5.31 |
| 14 | Assembler works for 3.9 hours to repair windows and then sends them to shipping and eventually to the customer. | 40.95 |
| 15 | After 2 weeks, customer calls. Some of the windows worked OK until they were installed. Then the bent flanges caused additional problems. Customer requests a Field Service Engineer to fix the problems. Engineer spends 35 minutes. | 15.60 |
| 16 | After many phone calls, it is decided to send a Field Service Engineer to the construction site. Times involved in making this decision: Engineer.............3.75 Hrs @ $26.75/Hr QA Supervisor.....1.75 Hrs @ $17.25/Hr Plant Manager.....1.75 Hrs @ $52.00/Hr Field Engineer.....1.60 Hrs @ $17.00/Hr |
248.70 |
| 17 | Field Service Engineer spends 37.0 Hrs in travel to site, fixing problems, and reporting. In addition, Engineer spends 1.6 Hrs on the problem. The Sales Manager spends 3.4 Hrs @ $48.00/Hr. Travel costs $987. | 1822.00 |
| 18 |
Weeks later, the same part is run again. It is found that the die can no longer run parts
that are in spec because it has been "relieved" too much. A similar chain of events occurs.
Time required:
Diemaker..........8.0 Hrs Supervisor........0.5 Hrs Operator..........2.0 Hrs Engineer..........0.7 Hrs Inspector.........0.9 Hrs |
169.08 |
| Scrap Value @ $0.17/lb | -17.00 |
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The Strategos Guide To Value Stream and Process Mapping goes beyond symbols and arrows. In over 163 pages it tells the reader how to do it and what to do with it. |
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