In building construction projects there are 3 factors that are used to measure project performance, one of which is cost. Efforts that can be made to minimize the cost overrun are knowing the causative factors and knowing how to mitigate them. The purpose of this study is to identify the causative factors, determine the dominant factors causing cost overrun, and efforts to mitigate them. The methodology in this research is desk research or research that uses relevant secondary data analysis, such as previous research with similar problems. The results of this study were 65 causative factors divided into 10 groups. The dominant factor causing cost overruns includes material, implementation and employment relationships, project documents, and project finance groups, one of them is fluctuations in material prices. Mitigation efforts have been obtained for the dominant factor, namely quality control in the field must be good, selection of professional workforce, and building good relations between parties.

The early years of company X were successful, and the company was able to grow into the successful enterprise that it is today. On the other hand, as the company grows, the challenges it faces become more complex, which has led to inefficient operations for the company. The problems stem from company X ineffective business organization as well as its inability to adapt to changing times and circumstances. The problems are showing up in their financial performance, which has shown a drop in revenue, which has stopped the company from growing. Internal observation will be used in this study to help figure out what the real problems are and what company X should do next. The 7S McKinsey model will be used to figure out what needs to be changed in terms of reorganization. We will look at the organization's strategy, structure, system, style, people, skills, and shared values. Seven company X employees were interviewed, and after the interview results are coded it was shown that their desire for the 7S is not align with the company's current state, which shows that the company needs to change. Lewin's Three Stages of Change model is used to redesign organizations once the change that was wanted has taken place. It will be used to figure out what steps company X should take to change their organization in a way that will work, starting with unfreezing, then making changes, and ending with freezing the transformation of the organization