More then 60 % of data used in decision-making processes come from chemical analyzes are produced. Analytical laboratories are nowadays forced to be ready to declare its reliability, confidence and credibility. Application of such care for quality brings extra cost and increases the price of analysis. Laboratories must take into account experience expressed in saying: Quality assurance is expensive business but up to the time when laboratory loses its first lawsuit. Doping in sport, as described in series of articles mentioned, was interesting demonstration of the uncertainty role in decision making process.