[Leica] QC at Leica revisited

[imxputs <imxputs@knoware.nl>]

My explanation of the pressure plate problem has been preceded by Eric Welch's 
identical info as he got it from US cources. Bottom line here is this I would 
dare to say: any industrial product (mass produced or small scale produced or 
hand crafted or a mix of these) can and will show defects occassionally. 
Humans and machines are fallible whatever the level of QC. The fact that some 
person made a fault is not in any way indicative of the general level of QC at 
Leica. The fact that one acknowledges it freely is very reassuring as this 
indicates a willingness to address the problem and an open eye for 
improvements. 
I would say that many on this list have a quite unrealistic expectancy level 
of what QC means in a modern industrial environment. There is also the 
psychological factor to assume that in the past everything  would have been 
better. 
Any component and any manual adjustment in the Leica production environment is 
governed by tolerances that are set to very small values. But every value is 
also ruled by the statistical fact that 95% of instances will be within the 
tolerance bandwidth  and 5% will be beyond this value span. Sometimes these 
tolerance deviations cancel out, smetimes they do not. The same for humans. 
Whatever you do to ensure that you are working at maximum attention level, 
sometimes your attention span will fail. Adding small deviations in a long 
chain might produce a defective product. And QC, working within the same 
statistical realities might fail to catch it. 
Leica users are often very critical and rightly so. They pay a high price for 
a product and demand first class quality. It is unrealistic to demand that 
defects  will never occur.

BTW 1: I am not an employee of Leica. I just happen to have some interest in 
the products of this company and use part of my free time to collect some 
facts about some of the products. I get some help from the Dutch importer as 
he provides me with samples of lense to test and I am allowed to use them as 
long as I like. In the case of the 70-180 more than two months.

BTW 2: Pascal tells us that he selectively transfers information from this 
list to a select group of people at Solms. This being a public list I assume 
he has a right to do so. I personally would prefer that he asks permission to 
do so from the person whose post he is about to transfer. At least that would 
be polite. 
I get many private emails from many Leica users around the world (not 
necessarily subsribers to the Lug, as my website also generates much 
informational traffic, asking me questions or informing me about problems 
(real, potential or perceived). If the topic is serious and I feel that Leica 
could or should do something here I ask permission from the person to give 
this info to Leica. I know there is a difference between private and public 
emails. Still I assume that public posts should be treated as owned by the 
person who originated it and not as free game.


Erwin