Microsoft commissioned Forrester Consulting to conduct a Total Economic Impactâ„¢ (TEI) study and examine the potential return on investment (ROI) very large enterprises may realize by deploying Office 365. The purpose of this study is to provide readers at large organizations (more than 20,000 users) with a framework to evaluate the potential financial impact of Office 365 on their organizations. View: Modern enterprises decrease costs and increase productivity with Microsoft O365