“…); how (for example, how to do it, whether one can use this method elsewhere, and so on.). 3) Five whys (five-why): the question of "why" five times consecutively given to receive a reply; each time, answering the question, it is easy to determine the true nature of the problem, often hidden behind more obvious reasons (Potemkin, 2010& Karepova, et al, 2015. 4) 4 M (sometimes with the addition of 5 M position "Measurement»): «Man» -operator (does he follow the standards, does he have the qualification, does he strive for perfection, and so on.).…”