CHAPTER ONE
INTRODUCTION
Background of the study
It is general knowledge that construction project owners have become more and more demanding, continuously changing their project’s design. Responding to market demands, they request changes at any phase of a project (Ibbs, 2012). Even years ago, studies revealed that 2025% of the construction period is lost as a result of inadequate design (Undurraga, 1996). Also, lower quality level construction projects could be 78% attributable to design change requests (Koskela, 1992). Change is considered as any addition, deletion or modification to the scope of a project that may cause the project to incur delays and adds extra costs to the original contract. As such, it can take many forms; however, it is the owner-acknowledged change that must receive more attention than the other types of change since this type can present a risk to owners and contractors. In the mind of owners, a change could be something very simple, but that perspective (most likely) does not consider the multiple effects one change may have on many other areas of the project. Each change could add to the cost of the original contract and cause delays in the project execution, while there could also be cases where a change requested would not add to the project’s cost and time. Some changes can even be beneficial to owners and contractors, but that situation is rather rare.
Therefore, a system that can evaluate changes concerning time and cost would be a valuable tool in the construction industry. Owners should be involved in their project, and the role and responsibility of an AEC team are to provide guidance, giving owners assessments of each requested change and its impacts on the project. If this system could support visualization capabilities to illustrate the impact of the contemplated change, then the owner would be able to see the big picture and make better and well-informed decisions. This system could also help avoid unnecessary conflicts and disputes between owners and contractors, and greatly reduce recourse to lawsuits.
Having a successful management system for applying, visualizing, analyzing, and organizing changes requested by owners would be a clear advantage. Dealing with changes in traditional fashion, namely using paper-based printouts of 2D drawings is no longer sufficient, as it is not possible to discover all ramifications of a contemplated change. This problem is addressed by the development of Building Information Models (BIM) by providing dynamic databases. BIM makes it possible to apply a change to a model and to get new information about the impacts of that change in the design model in every view. In other words, it can self-adjust the model’s database whenever a new change is applied to the model. However, the problem is that the user is only able to see a change, and the newly-affected model, but not the ripple effect of that change. Current BIMs only visualize the new model design, but do not highlight the components affected by the changed components.
In order to understand the impact of change on time and cost, there must be a link between the 3D model, project cost estimation and time scheduling databases. BIM represents that link with a 4D model (scheduling) and a 5D model (cost estimation). It takes considerable skill to create a link among different software interfaces and to provide a BIM all of these dimensions. As such, a more user-friendly software program is needed, one with the ability to generate all of these dimensions, 3D/4D and 5D, under one domain. This would make it possible to visualize the change ripple effect and analyze the cost and time impacts in a quantitative manner, before starting the construction phase. The study will therefore, look into effect of design changes in construction project.
1.2 Statement of the problem
The construction industry is well known for a high number, scale, and variety of serious conflicts due to owner-requested design changes. Changes are the major cause of project failure (Arain F. M., 2008). Most of the time, owners do not realize the consequences of the changes they are requesting from the contractors, and they invariably blame contractors if a project is faced with any disputes or claims. Hallock (2006) states that changes in the construction process causes difficulties among all the parties involved in the project and increases the probability of contractual disputes. Project changes have visible impacts on the project construction process; they affect the project schedule, cost, productivity, overall project performance, as well as cause ripple effects. Time and cost are of critical importance in today’s construction market. Hallock (2006) states that changes to project drawings affect project contract price and/or schedule. Upon receiving any owner-requested design changes, designers should give prompt feedback about the ripple effect of design changes on the project cost and schedule. This action is needed before the project owner makes any final decisions regarding the requested changes to the project’s design. However, present-day change management methods are usually more focused on managing the change impact on project’s labor productivity, and less on considering their impact on project time and cost. It is even less likely for current methods to consider the ripple effect of change in other parameters of the project.
Current approaches that rely on 2D project drawings are not sufficient enough to evaluate and analyze the impact of requested changes. With projects becoming increasingly complex, the impact analysis of design changes is also becoming much more challenging and time-consuming. These challenges have served to enhance the role of Building Information Modeling (BIM) in today’s construction industry. BIM allows real- time coordination of information in every view by combining a design model with a behavioral model (Autodesk, 2010). The design model consists of the project geometry and data. A behavioral model can be a change-management model since BIM has the potential to control changes through its dynamic process of building design. However, as Langroodi (2012) observed, “dynamic data are processed reasonably well in a single BIM, with all the necessary parameters explicitly defined. Changes across inter-related multidisciplinary designs that reside in a federated environment are significantly more challenging to manage.” However, many BIM projects still rely on paper-based printouts of 2D drawings that make it very difficult to see what is being changed in the model. An effective project change management system is needed to control and manage these changes. This system should be able to trace and visualize project changes, along with an analysis of their impacts on project cost and time. The growing popularity of using BIM in the construction industry while still lacking a cumulative change management system underscores the need to improve BIM-based change management systems. Effective management of multi-disciplinary models is needed throughout the dynamic process of building design and construction. This thesis presents an integrated BIM-based automated model for design professionals and owners. The goal is to visualize the ripple effect of design changes on other project systems, along with the analysis and estimation of a design change’s impact on project cost and time, to assist owners and designers in making appropriate decisions. The motivations for conducting this research are lack of an automated and quantitative BIM-based change management model for construction projects that can automate the process of owner-requested design change impacts’ analysis on the project cost and time, lack of visualization for analyzing the design changes’ ripple effect and tracking of the consequences; and lack of communication between project owners and designers, in selecting beneficial changes that respond to the owners’ desired criteria.
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