The document discusses lessons learned from 10 years of experience with the Internet of Things. It describes an enterprise approach to managing energy usage and equipment performance across thousands of buildings using the Siemens Site Controls platform. Due to the large amount of data generated daily, a building-centric approach relying only on alerts and alarms is ineffective. Instead, prioritized exception reporting, rule-based analytics, data aggregation, and ranking sites by performance indicators helps users focus on the most important issues. The "Real World" is unpredictable, so the system is designed to expect failures and handle large amounts of complex data.