In the theoretical part, the thesis focuses on terms related to the strategy of a company and on possibilities and methods used in the analysis itself. The main goal of the practical part of the thesis is to find, if the sales problems and interconnected decline in revenues in a company KSB, spol. s r. o, are caused by competitors and custormes, which is the opinion of its management. To solve the problem I used Porter's Five forces model, which includes other forces (supliers, new entrants and substitutes), that could also play a part in the aforementioned negative situation.