Does a large number of quality testing is an inevitable connection with product’s quality?
Let us explain:
How durable the product is declared from manufacturer's advertisement, how long of the service life, it is not a loose talk. It is achieved through rational design, proven by proper and adequate verification testing.
The above service life test is usually carried out before the product development, these samples will not be into the market, they are also engineering test samples.
Some of responsible companies will be regularly and randomly sampling to test during mass production to see if they meet the certification criteria.
Such as the 20000 times test for socket, which just do the plug test on welded parts, no need do the testing on an entire finished product.
Under normal circumstances, the finished products must be scrapped after all the above service life test, not allowed it to put on the market, consumers can use it in rest assured.