The research is aimed to 1) study the level and priority of the factors affecting the delay of construction projects and 2) provide suggestions in relation to the prevention of such delay. The sample is 520 people who were working for different construction projects. They were project managers project engineers field engineers and foremen. The data were collected by using online questionnaires and analyzed to find out mean standard deviation (SD) frequency correlation coefficient and confirmatory factor analysis. The findings reveal two significant aspects. First those who were working in the construction projects concerned about the factors affecting the delay of the projects at high level. Respectively the factors related to design resource external factors and others were taken into consideration. The factor regarding to work performance is regarded affecting the project delay at the highest level. Other factors i.e. the design external factors and others and resource have the affects at the lower level. Second the work-related factors can help prevent the project delay. In other words the construction plan and methods as well as the project management should be well-implemented in accordance with the design. The construction site should be on inspection considering its drawing. Regarding the external factors and others the public voices of those living around the construction site should be taken into consideration. Furthermore the effective use of the resources can be carried out by sufficiently preparing all materials tools and equipment for constructing any project effectively as a consequence.

The objectives for the study are the causes seeking and studying the critical level of problems for the construction project within the Rattanakosin Technology University; Salaya together with proposing the solution and the prevention as the guidance to manipulate the construction project within the university which may help to reduce the delaying problems. The study would use the data from questionnaires and the interview forms for the construction manager engineer foreman contractor and construction project committee who are working for the 14 constructing projects within the university. As for the data analysis the researchers would compare the critical levels and the frequency of each cause of the delay. The results showed that the Problem causes delays construction occurring in Rattanakosin Technology University; Salaya by simply selecting the S.I. 1 in 3 sequence ที่most valuable of each factor the resulting delays in construction divided into four main topics below 1. Man : of 6 factors the total number of 18 factors 2. Material : of 6 factors the total number of 18 factors 3. Machine : of 5 factors the total number of 18 factors 4. Method : of 6 factors the total number of 18 factors