Sustainable infrastructure delivery in Nigeria: implementation of the analytic network process for contractor selection

Purpose: This paper presents research findings that involve the use of analytic network process (ANP) to select contractors for build–operate–transfer (BOT) infrastructure in Nigeria. To deliver sustainable infrastructure (SI), a responsive methodology is required for contractors' selection process, which combines judgement and data for an effective outcomes prediction. Design/methodology/approach: Theoretically grounded on a system theory, sustainable infrastructure delivery (SID) model has been developed in this study. At the deductive phase of the model is the integration of the ANP (a multicriteria decision-making technique) for data synthesis. To obtain decision criteria, 55 sustainability indicators for contractor selection were identified from the literature review. The criteria were first developed to a web-based questionnaire where respondents were requested to rank the importance of the criteria towards selecting contractors that deliver SI, using Likert scale of 1–5 (where “5” is very important and “1” is not important). The results were analysed using factor analysis. Data were further reduced to 16 variables after multicollinearity issues in the data set had been resolved. To weigh the relative importance of the 16 criteria among contractors, ANP methodology was adopted for the second-round questionnaire. The seven-man decision panel that completed the pairwise comparison survey was selected through a purposeful sampling technique. The final survey results were synthesised by Super Decisions (computer package that implements ANP) trial version to rank contractors' options and predict outcomes. Findings/results: Sensitivity analysis of the research findings reveals that the 16 criteria have differential comparative advantages, which requires critical judgement during contractor's pre-evaluation process. Although the overall priorities rank multinational construction corporations (MCC) higher than local construction companies (LCC), MCC are not absolute to deliver SI. LCC are sensitive to some key criteria that are critical to the actualisation SI agenda. Originality/value: This study fills the gap in the knowledge of SID in Nigeria. The study theoretically suggests a framework to harmonise sustainability indicators in contractor selection. The findings further provide feedbacks that can be incorporated to Government's Ministries, Department and Agencies (MDAs) procurement policy to promote SID.