The purpose of the study is to apply quality improvement tools and techniques to find out the root causes of performance problems in the building process. Performance refers to the way people do their jobs and the results of their works, seeking to solve a performance problem frequently implement a specific intervention, such as training without fully understanding the nature of the problem, or ... [Show full abstract] determining whether or not the chosen intervention is likely to succeed. Performance improvement approaches using a systematic methodology to find these root causes, and then implement interventions that applies to specific performance deficits. Performance improvement indicators / measures in building process involve the ongoing measurement collection and analysis of aggregate data to improve occupancy requirements, expectations, and safety. Based on, reviewing quality leaders' approaches and contributions to performance improvement; quality improvement tools and technique uses show the effectiveness of performance improvement efforts in the building process. The paper successfully proposes a methodology for applying tree diagram as a quality improvement tool that can be used in architecture, to develop a map / plan describes performance improvements in the building process, which will help architects to monitor, improve, and facilitate optimal outcomes of continuous quality improvement, thereby, ensure high building performance.