RELATIONSHIP BETWEEN MATERIAL MANAGEMENT APPROACH AND SCHEDULED PROJECT COMPLETION TIME
Construction projects are known to experience time delays due to various reasons. The aim of this study is to find out if the material management approach used on building projects has a relationship with the scheduled completion time of the projects. Various literature were reviewed so as to identify the different material management techniques available and classification of time overrun. The study was carried out on building projects situated in Lagos and simple random sampling techniques was used to select respondents from lists provided by their respective professional bodies. The principal tool used for the collection of data was the questionnaire. The data collected were analyzed with the use of descriptive and inferential statistics including Pearson Product Moment Correlation Coefficient. The study revealed that there is a negative correlation between material management approach and variation in the scheduled completion time of a project. The study therefore concluded that the more the number of the material management approach adopted on a project, the lower the time overrun. It was recommended that construction companies should make use of more than one material management technique on construction projects so as to reduce the variation in scheduled completion time.
The Nigerian construction industry continues to occupy an important position in the nations economy even though it contributes less than the manufacturing or other service industries, (Aibinu and Jagboro, 2002). The contribution of the construction industry to national economic growth necessitates improved efficiency in the industry by means of cost effectiveness and timeliness, and would certainly contribute to cost savings for the country as a whole. It is also common knowledge that the implementation of the construction project in the industry is usually accompanied with time delay and cost increase as well as owner dissatisfaction (Hafez, 2001).
In general most (if not all), construction projects experience time delays and cost overruns during their implementation phase (Koushki and Kartam,2004). Numerous researchers, both in the developed and developing nations have also examined and identified the causes of time and cost overrun in the construction industry. Mansfield, Ugwu and Doran (1994), for example performed a comprehensive analysis of most important factors responsible for project delays and cost overrun in Nigerian construction projects. This analysis indicated poor contract management, financing and payment of completed works, change in site conditions, shortages of materials, design changes, subcontractors and nominated suppliers, other factors were price fluctuation inaccurate estimates, delays and additional works as factors responsible for project delays and cost overrun.
A comprehensive classification of causes of construction delays has also been determined by Henesy (1993). The classification system included materials, labour, equipment and financial constraints, as the main contributory variable to causes of construction time overrun. The list of major factors causing construction delay in Thailand by Ogunlana and Proumkunting (1996) included the inadequacy of resources supplies, client and consultant shortcomings and incompetence. Koushki and Kartan (2004) studied the impact of construction materials on project time and cost in Kuwait and identified the project related variable affecting the on time delivery of materials as material selection, time, type of materials and their availability in the local market.
The motivation for the investigation stems not only from the fact that many developing countries are now undertaking massive infrastructure development projects but perhaps more importantly, the effect of poor project performance in these projects can prove to be extremely detrimental to the often fragile economies of these countries (Manavazhi and Adhikari, 2002). Thus, the efficient use and management of material have an importance influence on a company’s profit and can delay construction (Abdul¬ Rahman and Alidrisyi, 1993). The aim of this study is therefore to find out the relationship between material management approach and scheduled completion time of building projects in Lagos State through the following stated objectives:
• Determine the material management approach in use on construction sites
• Determine if there is project time overrun and the perceived causes
• Find out if there is any significant relationship between materials management approach and the variation in scheduled completion time of building projects.
A research hypothesis that states that: There is no significant relationship between material management and variation in scheduled completion time of building projects was proposed to aid the direction of the study.
This study will be of importance to building professionals and the general public because it would not only clarify but also create awareness of the extent to which inadequacies in material management can adversely affect project performance. The study will also help contractors, clients, consultants and all parties involved in construction projects about ways of improving their current method of material management..