Due to the globalization and competitive markets in the new century, organizations should continually study both their structure and environment to verify that their structure has requisite integrity and adaptability. Designing an appropriate organizational chart is very debatable, especially in EPC (Engineering, Procurement and construction) companies, because there are always challenges between project and functional managers. In this study, design process, based on the R. L. Daft model, begins with whole recognition of the company and goes on with studying structural and contextual dimensions. Then, place of each dimension in the organic/ mechanistic spectrum is determined. Results show that organization structure of aforesaid company should be semi organic. Finally, using these results and whole recognition of the company, a proper chart for the organization is proposed.