Various optimization methods of heat source and operational design have been studied in order to reduce energy consumption in building sector. Some problems, however, remain to be improved. Furthermore, some designers plan building services by empirical laws in general buildings. Even if they plan them by optimum design, it isn't necessarily the most suitable that people who work at operation center operate heat sources. The authors have developed the optimization method of heat source using genetic algorithm and Lagrange multiplier to improve previous studies and have developed chart for operational design. If operators use the chart when they operate heat sources, they can understand easily which to operate heat sources and how much output. The result shows that a program which the authors made can calculate on condition that load factor is continuous, the calculation speed is quicker than the previous study, and chart for operational design is convenient for workers at operation center.