Openness is an expression of an enterprise’s ability to adapt to changing environment conditions and its ability to cooperate with different types of partners. A given company’s openness shows its readiness for the creation of dynamics of many business processes, including the creation of its competitive advantage. Due to the nature of today’s enterprises’ environment, mainly its “high velocity” & “complexity” attributes, openness of companies has to be multifaceted. Organization-customer relationships, called co-creation, are one of such facets. The capacity for effective co-creation gives a company the ability to gain a competitive advantage along with the chance for its permanent dynamization and sustainability. The main purpose of the paper is to present the framework and algorithm of co-creation as a method of reducing the complexity of the environment and dynamizing companies’ competitive advantages. A review of literature in the areas of open organization, open culture, partnership, co-creation, and competitive advantage provides a basis for understanding the process of co-creation. Collected data show that the activity of enterprises in this process is a key factor in the reduction of complexity of a company’s environment and an important stimulator of the dynamization of a company’s competitive advantage. The authors’ own CATI questionnaire survey research conducted in Poland showed the level of preparation Polish SMEs have to co-create.