By J. Stephen McNally, CPA What is the role of a plant controller? The answer may seem straightforward enough: the plant controller is responsible for personally coordinating the completion of all plant accounting and financial reporting activities related to his or her location. More specifically, the plant controller is responsible for cost accounting, financial closing and reporting, internal control and Sarbanes-Oxley compliance, tax, fixed asset accounting, inventory management, and related activities. But does the plant controller's role stop there? No.