In today's competitive and highly dynamic environment, managing and analyzing data to understand the business performance and to predict outcomes and trends has become critical. The traditional approach to reporting is no longer adequate, users now demand easy-to-use platforms and applications capable of analyzing real-time data to provide insight and actionable information at the right time. The end goal is to support better and timelier decision making, enabled by the availability of up-to-date, high quality information. The third IEEE International Workshop on Data Management (IWDM 2015) will be held on October 22, 2015 in conjunction with the ICDIM 2015 Conference that will take place from October 21 - 23, 2015 in Gyeongju, South Korea. The IWDM workshop aims at providing a forum for presentation of the latest research results, new technology developments, and new applications in the areas of Real-time Data Processing, Data Warehousing, Data Mining and Business Intelligence.