A systematic method to reduce the duration impact of change events on construction projects

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The only thing that is constant is change. (Heraclitus) Change events (CE) frequently occur on construction projects due to modifications to design and scope, as requested by owners. Therefore, CEs can directly impact a project's completion date, potentially resulting in unexpected time overruns. This is critical to both project owners and GCs. When deciding on CEs, owners need to navigate the tradeoff between the added value and the potential delay resulting from the change. A quick and accurate estimate of the impact of CEs allows a GC to build trust with the owner and gain financial benefits; an inaccurate or slow estimate of the impact of CEs will result in a loss of reputation and possibly also financial losses. Hence, it is crucial for both owners and GCs to arrive at an accurate and reliable estimate of how CEs can affect a project's completion date. PMs encounter two primary challenges when planning for CEs and calculating the duration impact of individual CEs and the cumulative duration impact (CDI) of co-occurring CEs: 1) Understanding the scope of changes, identifying activities that are affected, and estimating the amount of impact on the activities; and 2) identifying CEs that require immediate attention and prioritizing the incorporation of the co-occurring CEs based on their urgency. The state-of-practice methods do not provide PMs with a consistent and reliable means of interpreting CE data. In my observations of practice, practitioners solely rely on their experience and opinions of which trades and scopes will be impacted. This process is highly subjective and inconsistent. Unfortunately, the state of practice does not provide a standardized or organized process for incorporating several co-occurring CEs. Even though a body of literature exists on optimizing the initial project schedule, practitioners lack the necessary rescheduling methods that lower the duration impacts of co-occurring CEs. To address this gap, this study addressed three research questions. 1) Are there common features of CEs that assist PMs in understanding the scope and impact of CEs? 2) To what extent do the proposed labels assist PMs in understanding the CE data (i.e., CE scope and amount of change to impacted activities)? 3) Is there a CE prioritization method and a time allocation model that helps PMs reduce the CEs CDI by more optimally sequencing the co-occurring CEs? The primary findings show that there are common features of CEs (called CE labels in this dissertation) that are beneficial in 1) increasing the confidence level while also reducing the amount of effort in understanding CE scopes and the amount of change they impose to activities; 2) increasing the consistency of the results, and 3) increasing the likelihood of finding the correct CDI (CoCDI). The validation of the prioritization method shows that the method reduces the duration impact compared to the conventional method. In all the test cases, the prioritization method never underperformed the conventional method when the flexible time allocation model was used. The theoretical contributions of this work include: 1) Formalizing generally applicable labels for CEs to improve the CE planning process. 2) Assessing the effectiveness of the CE labels using the following metrics: the amount of effort, confidence levels, consistency, and the likelihood of finding the CoCDI. 3) Formalizing objectives and constraints that need to be considered in sequencing several CEs. 4) Developing and accessing a time allocation model and a prioritization method for the PMs that dramatically reduces the CDI of several co-occurring CEs. The practical contributions of this work include developing a CE planning method that, compared with conventional methods, allows the PMs to 1) Understand the CE scope and the amount of change it imposes to activities with higher confidence and less effort. 2) Obtain more consistent results through a more systematic and formalized method. 3) Quickly find a CE sequence that results in a lower duration impact. 4) Quickly identify the critical CEs that require immediate action. This research demonstrates that the formalized CE labels and prioritization method are one step forward in improving construction projects' change management processes. Appreciating the complexity and one-off nature of construction projects, future research can incorporate more drivers such as the availability of labor, materials, and equipment into the definition of CE labels. The prioritization method can also be further improved by incorporating labor productivity rates, including weather changes, organizational changes, and budget changes.


Type of resource text
Form electronic resource; remote; computer; online resource
Extent 1 online resource.
Place California
Place [Stanford, California]
Publisher [Stanford University]
Copyright date 2022; ©2022
Publication date 2022; 2022
Issuance monographic
Language English


Author Nikkhoo, Parisa
Degree supervisor Fischer, Martin, 1960 July 11-
Thesis advisor Fischer, Martin, 1960 July 11-
Thesis advisor Khanzode, Atul, 1971-
Thesis advisor Rajagopal, Ram
Degree committee member Khanzode, Atul, 1971-
Degree committee member Rajagopal, Ram
Associated with Stanford University, Civil & Environmental Engineering Department


Genre Theses
Genre Text

Bibliographic information

Statement of responsibility Parisa Nikkhoo.
Note Submitted to the Civil & Environmental Engineering Department.
Thesis Thesis Ph.D. Stanford University 2022.
Location https://purl.stanford.edu/cq570ct3323

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© 2022 by Parisa Nikkhoo

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