Determining Significant Mitigation Measures of Detrimental Variations in Public Building Projects in Tanzania

Detrimental variations worldwide have led to deleterious effects such as cost overruns, time overruns, compromised quality and abandonment of building projects. The study was about to identify and evaluate potential mitigation measures of detrimental variations in public building projects in Tanzania. This could help in minimizing detrimental variations and consequently safeguarding the anticipated value for money in such projects. Reviewed relevant literature resulted into identification of 17 potential mitigation measures of detrimental variations in public building projects. In total, 183 questionnaire forms were administered to architects, engineers, quantity surveyors and procurement officers for rating. Nevertheless, 143 responses were received constituting 78% response rate. Moreover, semi-structured interviews were made with 24 selected experienced professionals in public building projects to elicit individual’s expert opinion regarding mitigation measures of detrimental variations. Descriptive and inferential statistics such as frequencies, Cronbach’s alpha coefficient, coefficient of variations, Principal Component Analysis (PCA) and t-test were used to analyse and syntheses data. Study finding indicates the top five highly ranked potential mitigation measures of detrimental variations as joint efforts by project parties to control variation orders, clear project specifications, comprehensive site investigations, use of project scheduling techniques and use of knowledge base of previous similar projects. The agreement among respondents in rating and ranking mitigation factors was found to be significant. Overall, respondents tended to agree that all rated and ranked 17 mitigation measures could be practical to minimise detrimental variations in construction projects since their expected values of discrete random variables were greater than 3. Results from this study should help professionals, academicians, researchers and policy makers to reduce detrimental variations and subsequently improve performance of construction projects.