Abstract Construction industry faces challenges with regard to problems associated with productivity and the problems are usually associated with performance of labor. The performance of labor is affected by many factors and is usually linked to the performance of time, cost, and quality. Meanwhile identification and evaluating factors affecting construction labor productivity have been done in the last decade; however, a deeper understanding is still needed to improve the labor productivity. This study conducted with the aim to get the latest information on key factors that affect project performance in terms of project completion time and this is part of major research to model the interaction relationships between key factors affecting productivity. This paper reports on a survey made on respondents who involve in managing various types of projects in wide area in Indonesia. Respondents were required to rate using their experience how 113 factors identified from past researches, which grouped into 15 groups, affecting project schedule performance and then measured their level of affect. The result show that the groups of factors that give high effect are: supervision factors, material factors, execution plan factors, and design factors. In addition to these factors, for large companies equipment factors have also high effect. While in small and medium companies, owner/consultant factors also need special attention because it has high effect too. Research findings also show that health and safety factors has not been a concern of small and medium companies and only has some effect, while in large companies are better, although not as major concern and has average effect. The results will become worthwhile information in determining the major steps to improve the performance of project completion time and also as part of further research in modeling the interaction relationship between the key factors affecting productivity to improve the labor productivity in Indonesian construction industry.