“The cost estimates that the Department of Housing and Urban Development (HUD) developed for the four selected information technology (IT) investments were unreliable and, thus, lacked a sound basis for informing the department’s investment and budgetary decisions. GAO’s Cost Estimating and Assessment Guide (Cost Guide) defines best practices that are associated with four characteristics of a reliable estimate—comprehensive, well documented, accurate, and credible. However , none of the cost estimatesfor the selected investments exhibited all of these characteristics. Only one estimate—for the Customer Relationship Management investment —more than minimally met best practices associated with any of the four characteristics because it partially met the practices for a comprehensive and accurate estimate. The remaining three investments minimally or did not meet the best practices associated with the four characteristics. For example, the Enterprise Data Warehouse estimate minimally met all four characteristics; the Enterprise Voucher Management System estimate did not meet the characteristic for being accurate and minimally met the other three characteristics; and the Federal Housing Administration Automation and Modernization estimate did not meet the characteristic for being credible, while minimally meeting the remaining characteristics…”