Analysis of Delay Impact on Construction Project Based on RII and Correlation Coefficient: Empirical Study

The occurrence of a delay in the construction projects is common and significantly affects by enormous ways. This study investigates the typical causes of delay at different stages of construction and its effect in the Ethiopian construction projects. Using a questionnaire with 52 causes and 5 effects of delay, data were collected from 77 participants' selected based on purposive sampling from the different contracting organizations. The methodologies used in this research are relative important index (RII) and correlation coefficient. Based on the comparison, the impact of delay is found as, construction stage, pre-construction stage, and post-construction stage sequentially. The analysis of the relation in construction process shows; the average/overall is highly related, construction stage is the second related, post-construction stage is the third related and pre-construction stage is far part of all stages. As far as, overall/average causes of delay are comparable to all stages. So from the overall, the influential causes of delay investigated are corruption, unavailability of utilities at site, inflation/price increases in materials, lack of quality materials, late design and design documents, slow delivery of materials, late in approving and receiving of complete project work, poor site management and performance, late release budget/funds, and ineffective project planning and scheduling successively as unique to the Ethiopian construction project. The critical effects of delay investigated are cost overruns, time overrun, termination of contract, arbitration, and litigation sequentially. Although, the research is conducted on the Ethiopian construction projects, but it can also apply to other countries and further study.