The paper overviews the studies initiated by fundamental works of B. N. Pshenichnyi in the field of necessary extremum conditions, numerical optimization methods, optimal control theory, and differential games. Among them are new scientific fields such as processes with fractional derivatives and impulsive control systems.This year marks the 75th anniversary of the birth of B. N. Pshenichnyi, Academician of the National Academy of Sciences (NAS) of Ukraine, a world famous Ukrainian scientist, an expert in mathematics and cybernetics.Boris Nikolaevich Pshenichnyi graduated from the faculty of mechanics and mathematics of the Ivan Franko National University of L'viv, and the most part of his life worked in Kyiv at the V. M. Glushkov Institute of Cybernetics of the NAS of Ukraine. The range of scientific interests of B. N. Pshenichnyi was extraordinary and included network design and graph 157 1060-0396/12/4802-0157