Materials management on construction projects: A Case study of concreting works on sites in Nairobi

Abstract

Materials management can be defined as the planning and controlling of all necessary efforts to make certain that the right quality and quantity of materials are appropriately specified on time, are obtained at a reasonable cost and are available when needed. Materials management involves an integrated coordination of all materials related functions. These functions can be carried out efficiently only when sufficient emphasis is placed on early project planning, use of qualified personnel, adequate personnel training and proper communication amongst those involved in the process. The essential and desired site materials characteristics (materials attributes) of right quality, right quantity, right time and reasonable cost are evidently scarce on construction projects in Kenya as characterized by emergency purchases of materials, inadequate storage, material shortages and sometimes condemnation of materials and works by consultants. The construction industry is becoming increasingly competitive and materials management is now considered to be one of the frontiers for cost reduction to improve profitability and productivity, as materials can constitute 30-50% of the cost of the project. The problem of poor materials attributes therefore needs to be addressed and minimized. This study hypothesized t~at inadequate materials management is the cause of poor materials attributes on construction projects. The objectives of the study were to establish the extents of materials management and materials attributes on the construction sites, and to establish the relationship between the two.

In order to achieve the objectives, the study carried out a survey of concreting works on accessible active sites in both formal and informal construction in Nairobi. Data from the sites was statistically analyzed. Regression analysis between the two major variables; extent of materials management and extent of materials attributes, was carried out using SPSS software. Inferential statistics was used in hypothesis testing and generalization of the results. The study concluded that inadequate management of materials has resulted in the poor level of materials attributes on construction sites. The problem was found to be more severe on informal sites than on formal sites. The study recommends that a systematic and integrated approach is needed to manage materials and minimize the costs and effects associated with inadequate materials management.