Dittenhoefer’s Fine China
introduction
Overall, Steve Edwards, vice president of Marketing atDitten-hoefer’s Fine China, is very pleased with the success of hisnew line of Gem-Surface china plates. Gem-Surfaceplates are differ-ent from regular china in that the plates have aspecial polymer coating that makes them highly resistant tochipping and fad-ing. Not only are the plates more durable, theyare also com-pletely dishwasher safe.
In order to manufacture the new plates, Dittenhoefer’s hasleased a special machine to apply the coating and has put in placea drying system to “cure” the coating on the plates. The researchand development (R&D) lab has determined that in or-der toprevent defective plates, it is important that the machine applythe polymer coating at the proper temperature and in the properthickness. Specifically, R&D has written up the followingguidelines:
Coating Thickness. The optimalpolymer- coating thick-ness is 4 microns. If the coating is 7 5microns, the plates will take too long to dry. If the coating is 63 microns, the plates will be inadequately protected.
Coating Temperature. The polymercoating needs to be applied at a temperature between 160 degreesFahrenheit and 170 degrees Fahrenheit, with the target temperaturebeing 165 degrees Fahrenheit. If the temperature is lower than 160degrees, the polymer will not adhere properly and will flake off.If the temperature is higher than 170 degrees, the polymer coatingwill fade the design on the plates.
Quality Problems
Traditionally, quality control at Dittenhoefer’s has consistedof visually inspecting finished items for defects (chips, cracks,etc.) as they are being packed for shipment. This was accept-ablein the past, when defects were few and far between. With the newpolymer-coating technology, however, this has caused some seriousproblems.
For instance, on one Friday during the Christmas sea-son, thepackers noticed that nearly all of the plates they were gettingready to ship had faded designs, which suggested that thetemperature of the polymer-coating machine might be too high. Sureenough, when a supervisor went back to check on the polymer-coatingmachine, he found that the thermo-stat was set at 190 degrees.Apparently, someone had set the temperature higher to clean themachine but had forgotten to reset it back to 165 degrees. The goodnews was that the problem was easily fixed. The bad news was thatthe ma-chine had been running at 190 degrees sinceWednesday. In the interim, 2,400 plates had been runthrough the coating machine. In the end, Dittenhoefer’s had todestroy all 2,400 plates and was late making shipments to severalimportant customers.
In another instance, a worker just happened to notice that thepolymer-coating machine was not using as much raw mate-rial asexpected. When the worker measured the thickness of the coatingbeing applied to the plates, she found out why: The coatingthickness was only 2.4 microns. A quick check of plates being driedand those being packed revealed that they, too, had a coatingthickness of around 2.4 microns. While manufactur-ing was able tocorrect the problem and save these plates, no one knew howmany plates had been shipped before the prob-lem wasdiscovered.
the customer service department
The customer service office is responsible for pricing anden-tering customer orders, tracking the progress of orders, andmaking sure orders are shipped when promised. If an order is goingto be late or there is some other problem, the customer serviceoffice is also responsible for notifying the customer. In addition,the customer service office handles customer complaints.
As would be expected, Steve Edwards often visits the largerdealers to find out how satisfied they are with the prod-ucts andservice they have received. During one of these trips, Steverealizes there might be problems with the customer ser-vice office.When visiting Nancy Sanders, owner of Lenoir Home Furnishings,Steve gets an earful:
Steve, I understand that you have been busier ever since youintroduced the new line of plates. However, I feel that the servicequality has deteriorated and no one seems to care! Just last week,I found that an order I had expected in on Monday was not evenready to ship. No one called me—I just happened to find out when Iwas calling to place an-other order. Your information system alsoseems to be an-tiquated. The sales assistant apologized for theshipment delay and tried to be helpful, but she couldn’t tell methe status of my order or even when I had placed it! It seemed thatthe previous sales assistant had changed jobs, and no one knewwhere her notes were. Notes!? Why isn’t this stuff on a computer?It makes me have serious reservations about doing business withyou.
Steve is caught flat- footed by the criticism. When he gets backto the office, he puts together a letter to his top 200 customers.In the letter, he gives customers a self-addressed stamped postcardand asks them to list any problems they have had dealing with thesales office. He gets responses from 93 of the customers. Theirresponses are summarized here:
| Number of |
| Respondents Citing |
Problem | Problems |
Incorrect pricing | 23 |
Lost the order | 8 |
Did not notify customer | 54 |
with regard to change in | |
delivery date | |
Did not know status of | 77 |
customer’s order | |
Order incorrect—wrong | 4 |
products shipped | |
Slow response to inquiries | 80 |
Other problems, not | 11 |
listed above | |
| |
References
Suppose the polymer-coating machine currently provides thefollowing results:
| | Process Standard |
Variable | Process Mean | Deviation |
Temperature | 165 degrees | 2.55 degrees |
Thickness | 4 microns | 0.42 micron |
Polymer-Coating Machine: Sample Temperature and ThicknessMeasurements (taken when the process was under control)
| Temp/ | Temp/ | Temp/ | Temp/ | Temp/ |
Sample | Thick | Thick | Thick | Thick | Thick |
June 10 | 165/4.2 | 169/3.9 | 165/4.0 | 164/4.0 | 169/3.9 |
June 15 | 161/3.8 | 165/4.2 | 166/4.0 | 167/4.8 | 165/4.2 |
June 20 | 169/3.9 | 161/3.8 | 167/4.8 | 164/4.0 | 167/4.8 |
June 25 | 164/4.1 | 168/4.0 | 166/4.0 | 165/4.0 | 163/3.5 |
June 30 | 166/4.0 | 168/4.0 | 169/3.9 | 163/4.3 | 166/3.7 |
July 5 | 168/4.0 | 163/3.5 | 167/4.8 | 164/4.0 | 166/4.0 |
July 10 | 162/4.5 | 164/4.1 | 169/3.9 | 167/4.8 | 163/3.9 |
July 15 | 163/3.5 | 168/4.0 | 165/4.0 | 165/4.0 | 167/4.8 |
July 20 | 167/4.8 | 167/3.2 | 164/4.1 | 167/4.8 | 164/4.1 |
July 25 | 167/3.2 | 163/3.5 | 168/4.0 | 165/3.8 | 168/4.0 |
July 30 | 163/4.0 | 165/3.8 | 165/4.2 | 169/3.9 | 163/4.0 |
August 5 | 163/3.8 | 165/4.2 | 169/3.8 | 165/4.2 | 163/3.5 |
Q:1. On which dimensions of quality does Dittenhoefer’s compete?How are these dimensions being threatened by the problems in themanufacturing and customer service areas?
2. What do you think are the problems with the currentmanufacturing process as a whole and with the polymer-coatingmachine in particular? How might you use process mapping and rootcause analysis to get to the bottom of these problems?
3. Develop a Pareto chart based on the customer survey resultsfor the customer service office. What seems to be the key problems?How might you use the PDCA cycle to go about resolving theseproblems?
4.Suppose the polymer-coating machine currently provides thefollowing results:
| | Process Standard |
Variable | Process Mean | Deviation |
Temperature | 165 degrees | 2.55 degrees |
Thickness | 4 microns | 0.42 micron |
Calculate the process capability ratio(Cp) for both the tem-perature andthickness variables. Is the polymer-coating process able to meetthe engineering standards 99.7% of the time? Explain.
