Why do managers use strategic management?

Knowing that I am only 13, for me managers do strategies called PECs or Personal Entrepreneurial Competencies that includes how to manage their business properly. these are the examples of PECs, Vigilance for Opportunities, Creativeness, Commitment to Work Contract, High- Energy Level and many more, PECs is really a great guide. As long as you follow it, the more you successfully run your business.