This study was aimed to investigate the management process (POSDCoRB) that influenced the effectiveness of the organization consisting of work satisfaction and work quality accomplished at the scheduled time as well as the adaptability of the residential construction business in Bangkok Metropolitan. SMEs companies were selected according to registered capital from 1 million to 5 million baht only the companies with the profitability and unexceed total revenue of 30 million baht in 2016. 160 samples were used to respond to the questionnaire. Descriptive statistics Pearsons Product Moment Correlation Inferential statistics analysis stepwise multiple regression analysis were applied in the data analysis. It was found as follows. 1) The level of the management process of the residential construction business in Bangkok was high as well as planning and budgeting. However the process of people allocation organization direction coordination and reporting were relatively moderate. 2) Respondents in the residential construction business highly agreed upon the effectiveness of the organization work quality scheduled time achievement while the effectiveness of the organization in terms of satisfaction the organization adaptability were moderate. 3) The management processes had the highest correspondence with the effectiveness of the organization in terms of the coordination and adaptability of the organization followed by the budget which was related to the quality of the work. Finally 4) the management process concerning the coordination budget and organization management influenced the organization effectiveness of the residential construction business in Bangkok at the statistical significance of 0.01.

The purpose of this research was to study level of the preliminary cost calculate for a large building in Roi Et province and to study the factors that affected on initial cost reduction of large building constructions in Roi Et province. The sample group used in this research were devisers supervisors project managers and construction contractors in Roi Et province. There were 5 projects with a total of 145 people. The instruments used in the research were a 5 level rating estimation questionnaire. Data were analyzed by using frequency percentage mean standard deviation and the hypothesis tested by using Multiple Linear Regression with (Enter Regression). The result of the research shows that An analysis of opinion on principal control of large building constructions in Roi Et province. It was found that the practice level was at the highest level. Which is arranged in order from the highest average to the lowest namely machinery cost material cost contractor cost operating cost and labor costs respectively. and The analysis of Regression Model Development for Preliminary Calculate Cost of construction works had resulted in lowering the initial cost of large building constructions in Roi Et Province of 5 factors included structural design architectural design interior design system design and exterior design. Resulting in reducing the initial cost of large building constructions in Roi Et province with statistical significance at the level of .01 level.