This paper presents grey wolf optimization - GWO. After presenting the biological basis of GWO, it explains the method itself and then the main algorithms of the GWO method as well as their mathematical models. The Grey Wolf Algorithm (GWO) is presented in detail as well as the manner of its operation and it application to optimization examples of engineering problems, such as: optimization of speed reducer, pressure vessel, spring, car side impact, cone coupling and cantilever beam. At the end, the results obtained by the GWO method are compared to the results previously obtained by other methods.

In this paper we will demonstrate how Marine Predators Algorithm (MPA for short) can be used for solving certain optimization problems in applied mechanics. In the first part, biological fundamentals, as well as method explanation are given. Afterwards, MPA algorithm and its ' applicability is explained in detail. The pseudo code for this algorithm was written using Matlab R2019a software suite. This algorithm can be used for optimization o f engineering problems, such as: pressure vessel optimization, cantilever beam optimization, cone clutch optimization and speed reducer optimization. In the end, all the results for the fore mentioned problems, as well as a result comparison with other methods are shown.