Carol-Ann Berlioz from Sparling Logic lists several roadblocks to decision management systems or rules engines as they are still often called. And she also lists great benefits of using them: Link

• Flexibility to change your decision logic as often and as quickly as desired
• Integration and deployment of predictive analytics
• Testing from a QA and business perspective
• Measure business performance in sand-box and in production
• and yet, it will integrate beautifully in your infrastructure