Optimization of Cost and Quality in Oil and Gas Construction Site Using Modified Composite Multi-criteria Decision Analysis

Abstract

The success of a project hinges on aligning the client's expectations – value for money and quality of project delivery. This is especially essential in the petroleum sector of the economy, because of the dire challenges such as the prevalent cost overruns and quality non-conformances in various countries, particularly in developing countries like Nigeria. Therefore, there is a need to intentionally undertake a study that seeks to optimize the cost and quality objectives of a project specifically. In this study, a modified composite Technique for Order of Preference by Similarity to Ideal Solution, (TOPSIS) with the Analytic Hierarchy Process, (AHP) algorithm approaches were engaged for optimal performance of the alternatives. Initially, the Relative Importance Index, (RII) validated the criteria ranking, such as corruption, late client payments, and contractor insolvencies, aligning closely with the literature, albeit with minor percentage deviations ranging from 2.6% to 10% lower. According to the TOPSIS/AHP analysis, the client/consultant alternative emerged as the top preference, closely approaching the model solution value of 0.673, followed by that of contractor at 0.618 and materials/equipment at 0.511. Additionally, labour with 0.411 ranked fourth, whereas risk/external factors and procedures/controls hierarchically came fifth and sixth with 0.296 and 0.230, respectively. Remarkably, these results affirm the client as focal point of in lead role of directing, supporting, and integrating construction site activities without usurping/assuming the exclusive responsibility of the contractor's contractual obligations, ultimately ensuring successful project performance, enhanced fulfilment of the expectations and needs of both clients and stakeholders.

Keywords: Optimization, cost, quality, composite, TOPSIS/AHP, decision, construction site

DOI: 10.7176/IEL/15-1-01

Publication date: January 31^st 2025