Energy utilization management is one effective strategy for reduction of greenhouse gas emissions associated with large factories. Several projects based on this strategy are reviewed to identify key elements of success. Specifically, the projects involve energy information systems, effective use of management reports, demand ventilation, and energy usage correlation to production. Success stories are presented, along with projects that did not deliver anticipated results.Elements of a successful reduction effort are examined, along with lessons learned. The central conclusion is that success depends on an effective problem-solving methodology that includes clear problem definition and root cause analysis.Successful GHG emission programs based on an energy usage reduction strategy include these key elements:1. Problem solving methodology that precedes any consideration of solutions2. Review of temporary fixes in order to sustain energy savings3. Simple energy utilization information system4. Focus on exactly meeting utility requirements (no more, no less), as they change with production activityThese two cases are presented anonymously at the request of the companies involved. This allows objective discussion of successes and failures without unintended consequences.