If we start from a theoretical abstraction that company contains only technology, with no employees, system non-organization will be minimal, and its predictability will be great. However, as soon as we involve a human factor, a company takes a character of socio-economic system with likeliness character. Man is the holder of useful work, but he is also the factor of entropy increase due to deviation of actual productivity from one that is objectively conditioned. Accordingly, consulting performance evaluation is a development approach, whose role is to obtain more consulting process controls, unlike the exact measurement that could be carried out in natural sciences. Performance is influenced by numerous factors, that have interwoven and multiplicaded impact. Consequently, accurate measuring of consulting impact is considerably complicated, in many situations requires highly spohisticated statistic metodology and its appliance requires fullfilment of numerous conditions.