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The importance of the sampling process on the analytical result on the one hand side and the measures derived from the evaluation of the analytical data on the other hand is too often neglected or underestimated. Analytical techniques are much more precise than sampling techniques ever can be. Looking at the possibility to fail during this analytical process the interval for systematic failures during sampling is about 103 times higher (rough estimate) than the error limits of the measurement itself (see Figure II.2). Which means even the most precise analytical technique will not lead to the solution when the sampling is insufficient [3].

If for example a coating failure occurs and the task is to investigate the root causes, it is not a good idea to grab one, not very well defined sample out of a pile of scrap and analyse it without any plan.

The sampling must be representative, well designed and perfectly documented. The question of what is representative cannot be answered by production staff. Therefore, well-educated employees have to do that job and take care for a good documentation which includes:

 sampling location

 sampling date and time

 material type and lot

 environmental parameters

 sampling intention