Conceptual basis for the mathematical formalization of navigator fatigue

Fatigue of navigators, as well as of all other crew members, is a resonant and at the same time still unresolved problem of modern maritime shipping, the consequence of which is a decrease in labor efficiency and an increase in the likelihood of maritime accidents and incidents. The article analyzes some private and general approaches to fatigue assessment and control, presents the principles of mathematical formalization of navigators' fatigue, substantiates the classification of fatigue, including three types of fatigue - short-term, medium-term and long-term, and records the fatigue functions in general. Each of the functions contains three categories of arguments: time, arguments affecting only a specific type of fatigue and arguments determining the relationship between types of fatigue. An explanation of the arguments of the last category, determining the fundamental difference of the proposed formalization method, is given in tabular form. The presented concept, as a result of its development, can be transformed into a full-fledged method of fatigue management for navigators, taking into account not only the accumulation of fatigue during a watch due to insufficient sleep and rest, but also many other, including long-term, factors of fatigue. To ensure such development, an open list of tasks for continuing the research is formulated in the conclusion of the article.