Over the past number of years, our "Designing Efficient Workbooks" whitepaper has been a popular guide to improving performance. This session, presented by a student of the author, will cover the main causes of slow workbooks and offer practical suggestions on how to improve them. Expect to address topics such as defining efficiency (and why you should care), and diagnosing the cause of slow workbooks (via workbook design, the query, the data source, or environmental factors).