Browsing Theses and Dissertations by Authors
Improving Construction Processes in Nigeria using the Last Planner SystemSuresh, Subashini; Ahiakwo, Ograbe, A. (2015-02-09)This thesis describes a research investigation into the implementation of the Last Planner System (LPS) in Nigeria, to improve construction processes within the Nigerian construction industry. LPS is known to be the most developed practical use of Lean Construction. It focuses on minimising the negative impacts of variability, uncertainties, buffers, making projects more predictable, creating reliable work plans and convalescing collaborative planning. However, the Nigerian construction industry is associated with a number of challenges which impair its performance. These challenges were grouped and classified into six major barriers: these include: supervision and quality control, fluctuation and variations, subcontractor involvement, resistance to change, cultural issues, and lengthy approvals. Consequently, a Design Science Research (DSR) approach is adopted to evaluate the effectiveness of implementing LPS in construction projects in Nigeria. In order to achieve this aim, an Action Research strategy is adopted and three case studies are reported; two of these cases describe how LPS was successfully implemented in construction projects within Nigeria. While the third case involved an investigation into the state of production plan reliability, of a successful project in Nigeria. These projects were selected based on non-probabilistic sampling from different geographical locations in Nigeria to represent different kinds of construction projects within the country. The first and second cases involved the implementation of LPS within the construction of a prototype student’s hostel and the construction a 4 Kilometre single carriageway road respectively. The third on the other hand involved the construction of a multipurpose hydro-power dam project; where comparisons were made between typical LPS projects and the project management techniques applied within the project. Data was collected through observation site activities, interviews, documentary analysis and questionnaire survey. The data generated was subsequently analysed by means of content analysis and evaluated in terms of its reliability, validity, representativeness, flexibility, rigour and reflexivity. In view of the LPS implementation within the two case studies, six barriers were identified and classified together with the six barriers associated with the Nigerian Construction industry. These barriers were linked, measured and ranked in averages of their degrees of occurrences. It was revealed that the major barriers were cultural issues and resistance to change, while the others include; lengthy approval, subcontractor’s involvement, poor supervision and quality, fluctuations and variations. Hence, a framework was developed to mitigate these barriers, when implementing LPS in construction projects in Nigeria. The main steps of the framework include: the need to identify purpose; the need to identify stakeholders impact; the need to obtain Sponsorship; the need to build a cross functional team; the need to create measurement indices; the need for training on Lean techniques and LPS; and finally the need to create a right working climate. Furthermore a focus group between construction practitioners was organised to test and evaluate the framework developed. It was revealed from the focus group that the framework has the potential to facilitate the implementation process as proposed.