| dc.description.abstract | Construction is a costly and labor-intensive activity which requires efficient management of resources for successful delivery. This delivery is however hampered by cost and time overruns, a prevalent phenomenon evidenced both locally and internationally in the industry.
It can be argued that the impediments to enhanced efficiency in the building industry are no longer predominantly technical. An organization’s efficiency greatly depends on its ability to manipulate and synthesize information pertinent to its processes for its benefit. The sets of information generated from and absorbed into the construction process keep spiraling, so much so with numerous participants feeding into the process. The conventional two-dimensional information management model of construction is however not adjusting to these convolutions, resulting in difficulty in coordination of this information. The ability to relay information in consistent and compatible formats is crucial to achieving reduced downtime and increased quality and efficiency of the construction process. This has resulted in the development of Building Information Modeling (BIM), a process and tool through which a project’s lifecycle information is streamlined and manipulated to improve the effectiveness of the construction delivery process.
This study sought to evaluate the role of BIM in reducing cost and time overruns experienced in 2 dimensional (2D) based construction. It was guided by four objectives: to determine the cause(s) of cost and time overruns in construction projects, to identify the significance of information management challenge(s) in 2D modeling in contributing to time and cost overruns, to establish the level of BIM maturity at which construction professionals are operating within Nairobi county as well as to identify the role of BIM and its effectiveness in reducing time and cost overruns experienced in 2D based construction. The study area was limited to Nairobi County considering a study sample across three construction profession strata; Architects, Engineers and Construction Managers. Purposive sampling of construction professionals with knowledge or experience in BIM as well as experience working in Nairobi County was done for an exhaustive study. The total sample size of 99 was considered. Data was collected through use of structured questionnaires distributed via Survey Monkey®. Descriptive summaries such as frequencies and means were derived from Survey Monkey® analytical tools. Z test and regression analysis were conducted using SPSS software. The data was then presented in form of tables and charts.
The study determined the causes of cost and time overruns in decreasing order of frequency including frequent design changes, poor project scheduling, slow client decision making, poor team collaboration, poor contract duration estimation, inadequate design, contractor inexperience, complexity of projects, project risk and uncertainty, material shortages, accidents on site, designer inexperience and poor scope definition. Challenges in 2D modeling which are significant in contributing to cost and time overruns were further established and ranked in decreasing order of significance. Lack of interlinking of changes made on one document which relate to other documents are not interlinked was ranked as the most significant 2D challenge. This was followed by tedious and error prone element clash detection, lack of multidisciplinary interaction resulting in information loss and repetitive work, inability to simulate actual scenario on site and lack of interlinking between 2D drawings with cost and time schedules. The use of lines and symbols to represent 3D objects which leads to ambiguity and misrepresentation was identified as another challenge in addition to the difficulty in confirming completeness of 2D drawings without a reference model.
The role of BIM in reducing cost and time overruns experienced in 2D based construction was identified as collaboration and coordination among project team members, detection and elimination of errors and omissions in design, design management of complex projects, design or order management change, speedy stakeholder decision making, reduction of requests for information, schedule estimation and monitoring, cost estimation and monitoring, material scheduling and project risk management. Further, BIM was confirmed to be effective in playing all these roles.
The study recommends government support in the implementation of BIM through national policy frameworks sanctioning and formalizing BIM implementation procedures. It further endorses investment of construction professionals in training on BIM procedures and software since full benefits of BIM can only be achieved if all construction participants operate within the platform. A review of construction tertiary school level curriculums to include BIM training is also recommended for generation of BIM savvy graduates. | en_US |
