This research is the comparative study of three forecasting methods on SET 100 index. These methods are Simple Exponential Smoothing method Holts method and Box-Jenkins method. Two sets of data were used in this study. The first one used as a training set was collected from January 2 2008 to September 30 2011. The other one used as a testing set was collected from October 3 2011 to October 14 2011. We propose that the most appropriate forecasting method is the one which give the lowest MAE MSE MAPE and diagnostic checking. The results show that Holt’s method displays the lowest MAE MSE and MAPE. The next one is Box-Jenkins method while the Simple Exponential Smoothing method exhibits the highest value of all three indicators. However the model from Box-Jenkins method is the only one way that reveals no residual autocorrelation. This leads to the conclusion that the appropriate models for forecasting of SET 100 Index is ARIMA (213).

This research was a study of energy management in public building. The goals of this project are to decrease energy consumption and to enhance energy management system of the building. Regarding the energy survey the building lights are turned on for 24 hr. per day in order to satisfactorily serve the customers. In the study it was found that the energy consumption of electric light on the fourth floor roof can be reduced by changing the light “Floodlight MH. 4x250W” to be “High bay LED 4x150W” For the merit this project can save the energy around 6632570 baht per year and switching towards high-efficiency lanterns and replacing FL. T8 light bulbs installed in the walkways with FL. T5 models. This reduces lighting cost by 361425 baht per year. Moreover the energy management system was analyzed by using SWOT Analysis. As a result we observed the barriers to communication must be overcome to promote energy conservation. One approach is to increase the performance through the use of communication strategies within organizations. This method will help align employees understanding and participating in activities of conserve energy.