Comparative Study of Factors Leading to Detrimental Variations in Public Building Projects

摘要

Variations with their attached effects on construction projects continue to be a chronic problem worldwide and the situation is getting worse. Many public building projects, particularly in developing countries have been subjected to detrimental variations often leading to cost overruns, time overruns, project abandonment, rework, disruption and conflicts. Consequently, these have led to non-fulfillment of project objectives. Relative to their geographical locations in East African (EA), the economies of Tanzania (TZ) and Uganda (UG) mainly depend on agriculture and almost have similar characteristics and investment in the construction sector. This study was aimed at identifying, evaluating and comparing the causes of detrimental variations in public building projects in Tanzania and Uganda. This could help in monitoring the trends of deleterious variations and safeguarding the anticipated value for money in such building projects. Pertinent literature was reviewed coupled with structured questionnaire administered to 183 professionals in Tanzania to elicit relevant information with regard to causes of detrimental variations. Nevertheless, 143 responses were received constituting 78 percent response rate. Relatively, the study in Uganda used structured questionnaire administered to 54 professionals with 34 responses constituting 65.4 percent response rate. Statistical analysis such as frequencies, coefficient of variations (COV), Cronbach’s alpha reliability test and t-test were used to analyse and syntheses data collected from questionnaires. Subsequently, the causes of detrimental variation variables were ranked according to their importance and occurrence. The agreement among respondents in rating and ranking the factors of detrimental variations was found to be significant. Findings suggest the top five highly ranked factors of detrimental variations in both countries as change of plan or scope by client, design discrepancies by consultant, lack of judgement and experience by contractor, weather conditions and change in economic conditions. These factors significantly contribute detrimental effects to construction projects performance, thus jeopardizing the integrity of the construction industry. The study findings should help policy makers, construction practitioners, researchers and academicians to improve construction performance.