An integrative literature review on the causes of delays in construction projects: evidence from developing countries

Delays have commonly been a serious problem. This study aims to evaluate, criticize, and synthesize the literature on the causes of delays in construction. A total of 70 journal articles from 33 countries focussing on identifying the causes of delays were critically analysed. The main findings of this study are that the questionnaire survey is the most commonly used data collection method, the project phases at which the causes of delays are identified is not clearly stated in the majority of the reviewed articles, there is no agreement on the classification of causes of delays, the number of causes of delays studied by researchers greatly varies, the term 'delay' is not clearly defined in the majority of the articles, there is no standardized terminology for the causes of delays, key variables such as type of project, project delivery system and contract type are mostly ignored, and the location of the project is an important variable to consider when identifying the causes of delays. The findings of this study provide researchers, practitioners, and construction professionals with a detailed reference, which can assist them in better understanding the causes of delays, taking the necessary proactive actions, and improving the overall project performance.