One of the most important efficiency losses in industrial boilers is combustion loss. In this study, the risks that reduce boiler combustion efficiency are listed by using the Failure Mode and Effects Analysis (FMEA) technique. There are many factors that cause combustion loss. The relationship diagram, which is one of the process development tools, has been used to research the relationships between these factors and determine the main factor causing combustion loss. As a result of this evaluation, it has been specified that the main factor causing combustion loss is the inappropriate O2 / fuel ratio. To find a solution to this problem, the Poka-Yoke mistake-proofing technique has been applied and the O2/CO trim combustion management system which continually optimizes O2 / fuel ratio has been proposed. Thus, the combustion quality will be kept automatically at the optimum level without being affected by internal and external conditions. The annual energy saving of this investment has been calculated, and it has been determined that it will pay itself back in 4 years. This study is thought to be an example for other industrial organizations using industrial boilers.