According to resource-based view, market orientation can help companies to enhance performance. By looking at customer portfolios of global 3PL companies, certain customer sector specialization can be noticed, hence, market orientation is an asset that is valuable and provides a competitive advantage to companies that possess it. A detailed in-depth look into internal processes of 3PL companies is needed to demonstrate interrelationships between 3PL key resources, which are information, knowledge, relational and human resources. The purpose of this study is to develop a model that would demonstrate transmissions between commercial and operational processes in 3PL companies. A system dynamic approach is chosen to demonstrate these interrelations. This study is organized as follows. First, an empirical literature research is done to discover studies related to resources of 3PL companies. Second, a model demonstrating commercial and operational processes of 3PL companies is developed, based on system dynamics approach. Third, approbation of the model is done to test multiple scenarios of 3PL portfolio planning. As the result of the study, there are suggestions developed for 3PL companies’ management teams addressed to improve the portfolio planning process within 3PL organizations.