Variation Mitigation Model to Enhance Construction Performance of Public Building Projects in Tanzania

Detrimental variations are variations which negatively impact the project performance resulting into scenarios such as cost overruns, time overruns, project abandonment, rework, disruption and conflicts. These scenarios have led to non-fulfillment of project objectives. The objective of the study was to develop a mitigation model that helps to mitigate detrimental variations in public building projects in Tanzania. Specifically, the research question was how can detrimental variations be minimised in building projects? Literature review was carried out. Data were collected using questionnaire survey, group discussion and case studies. In total, 143 professionals (architects, engineers, quantity surveyors and procurement officers) participated in the survey. Statistical analyses such as Analysis of Variance (ANOVA), T-test analysis, Spearman’s rho correlation analysis and Principal Component Analysis (PCA) were used to analyse data and obtain relationships of variables. The analysis generated significant independent and dependent variables that formed the basis for the developed detrimental variation mitigation model. The model was validated through focus group discussion to test the model’s usefulness, clarity and applicability. Findings from case studies suggest that building projects suffered detrimental variations. The developed model when used significantly contributes to reduction of detrimental variations. Project parties should use the developed best practice model to enhance performance of construction projects.