Impact of variation on project delivery in Oyo state, Nigeria

Variation in construction projects are very common and likely to occur from different sources, by various causes, at any stage of a project, and may have considerable negative impacts on items such as costs and schedule delays. This study is aimed to assess the causes of variation on construction project, the factors influencing the occurrence of variation on project and to determine the impacts of variation on project delivery in relation to cost and time. Questionnaire survey was used; out of 80 questionnaires that were sent out 78 questionnaires were retrieved from respondents in the contracting firm, consulting firms and government parastatals in Oyo state. The findings showed that; owner’s financial problem, change in specification by owner, change in scope of the project, care the most important causes of variation. The presence of specialist works, unforeseen conditions, and incompleteness of design are the top factors influencing the occurrence of variation. The most important impacts of variation on project delivery in relation to cost are quality degradation, increase in project cost, delay in completion and logistics delays while the most important impacts of variation on project delivery in relation to time are logistics delays, delay in completion and quality degradation