Now you guys are getting into my area of expertise. Quality has to be designed into and not inspected into a product. Inspection's place is as a measuring tool and in the case of an identified quality issue, a filter to bring a sub-standard lot back up to acceptable standards. Quality systems are also designed to manage manufacturing defects because no matter how good the design, people still assemble the product. Most of the defects that customers see in new cars are the result of manufacturing errors combined with escapes from the quality system, not design flaws. They escape because no manufacturing system is perfect.
It may seem odd but a quality product is not always the absolute best design. A quality product is one that meets the customer's needs at the lowest cost. Mercedes and most other manufacturers can design cars that will run reliably for 1,000,000's of miles but these cars would not meet their customer's needs. For starters, they would be way too expensive. Plus, I suspect that they would weigh about 3X as much as a modern S class Mercedes because the over-engineered (never to fail) drive line, charging system, starting system, etc would be much more heavy duty than what's being produced today. The cars would probably get worse gas mileage than an early 70's Caddy. Now back to the "customer's needs at the lowest cost" statement that I made. Mercedes are designed to fill a market segment and that segment has a finite price range. I know that they sell some cars in the 100K+ range but they sell very few of those. Their main lines are the C, E & M class Mercedes and these range from the mid 30's through the 70's for some AMG models. Every one of these cars are full of design "compromises" to control cost but there is nothing wrong with controlling cost. Also, every car manufacturer (no exception) is driven to find the lowest cost sources of quality components possible including Lexus, Toyota and Honda. It's just part of business. There is another metrics tied to quality - MTBF. MTBF stands for Mean Time Before Failure. Every major module on a car has a MTBF rating - it's the expected average lifespan of the part. This is as much true for the engine as well as it is for the alternator. Even the door hinges have a MTBF rating. The designers expect the doors to be opened & closed a certain number of times during the lifespan of the car & hinges are designed to support this plus a reasonable buffer. I've owned enough Mercedes to know that the MTBF of the accessory items is not too long on the older models. For example, I would expect to loose an alternator before 100,000 miles. But today's cars run 150,000 + miles before accessories start dropping out. Why? Because the components have a much better MTBF rating! In other words, they are higher quality. Also, I've been around long enough to remember when your "new car", Mercedes included, would have at least 6 annoyance items that you would have to get the dealer to "fix". These just don't exist anymore and it's another sign of the higher quality of today's cars. Then there is another element - early life failure. No matter how good the design, some percentage of modules will fail prematurely. The failures could be due to random component failure in an electronic assembly or a mechanical failure. Thanks, Tom Hargrave www.kegkits.com 256-656-1924 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Werner Fehlauer Sent: Saturday, January 13, 2007 11:58 PM To: Mercedes Discussion List Subject: Re: [MBZ] Mercedes Quality Chris - I don't think your understanding of Japanese and German QC is correct. Both (and probably all) manufacturers have peaks and valleys in their QC measurements. The trick is to narrow this gap, and the successful companies work very hard to do quality testing at the lowest level (i.e. at the suppliers) and then continue checking as components and material make it into the final product. The more comprehensive this process, the better the final product. If QC was perfect and the final products never had failures, there would be no need for a warranty! In the case of our favorite car brand, I believe that too much of the initial QC has been left to suppliers, and therefore they have allowed parts into the final assembly that may have more latent flaws than can be accepted. Part of this problem is the age-old concept of low bidder; if a supplier had more control and testing, they would have to raise their prices, and thereby lose their contracts. All companies try to buy their material at the lowest cost, in order to sell the final product competitively. It just appears that at this time, some of the Japanese firms have managed to have tighter control of their suppliers. But there is "junk" out there to buy from any country - its still caveat emptor! Werner ----- Original Message ----- From: "Chris Kueny" <[EMAIL PROTECTED]> To: "Mercedes Discussion List" <mercedes@okiebenz.com> Sent: Saturday, January 13, 2007 7:31 PM Subject: Re: [MBZ] Mercedes Quality > Somebody who knows more than me should point out the difference in > Japanese > QC vs German QC. The Germans accept a certain amount of bad cars, and try > like heck to catch them and fix them before shipping them, while the > Japanese see any bad car as a problem in the process, and find a way to > fix > the process so that problem just doesn't happen anymore. Have I got that > right? > > Chris K > Cayce, SC > _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
