A Supervised-Reinforcement Learning Model for Automated Clash Resolution in the Construction Industry

Harode, Ashit

A Supervised-Reinforcement Learning Model for Automated Clash Resolution in the Construction Industry

dc.contributor.author	Harode, Ashit	en
dc.contributor.committeechair	Thabet, Walid Y.	en
dc.contributor.committeemember	Gao, Xinghua	en
dc.contributor.committeemember	Mills, Thomas H.	en
dc.contributor.committeemember	Leite, Fernanda	en
dc.contributor.department	Myers-Lawson School of Construction	en
dc.date.accessioned	2024-09-25T08:00:36Z	en
dc.date.available	2024-09-25T08:00:36Z	en
dc.date.issued	2024-09-24	en
dc.description.abstract	Clash Coordination is a crucial step in ensuring timely and cost-effective project delivery. While software tools like Navisworks and Solibri have improved the process of aggregating models and conducting clash tests and categorization, resolving clashes remains a slow and manual task. The reason for this slow process can be attributed to the meticulous nature of the process where design coordinators need to ensure that resolving one clash does not lead to new clashes. With the advent of machine learning and its application in construction, more research is being conducted to automate construction tasks to increase productivity and reduce the cost of the project. One such task currently being researched is to automate clash resolution. Researchers have explored the use of machine learning, specifically supervised learning, to automate clash resolution with successful outcomes. A search of the Web of Science database shows 7 publications that discuss the automation of clash resolution, automation of clash correction sequence, and automation of selection of relevant clashes. The authors to further analyze the content of these publications used VOSviewer to create a word map of keywords contained in the title, keywords, and abstract fields of these publications to analyze word co-occurrence. The word co-occurrence analysis revealed that the publications have explored supervised learning as the machine learning category of choice for automating clash resolution. However, the same analysis also showed the lack of terms such as data scrubbing, feature selection, feature engineering, and domain knowledge. These terms are an essential part of developing a machine-learning model. This analysis led the authors to believe that even though research is being conducted to automate clash resolution, a systematic approach to develop a machine learning model to support the automation of clash resolution is missing. Also, though these researches show significant accuracy in terms of automating clash resolution, they fail to justify the selection of their feature and label space. Another limitation of the current state of the art is that the effectiveness of supervised learning in automating tasks is limited by the availability of a large amount of labeled data, often unavailable. To address these research gaps, in this dissertation the author's first contribution to the body of knowledge is a phased systematic approach to develop an automation model for clash resolution. Since in machine learning selection of appropriate feature and label space is critical in developing an optimum and explainable solution, it is crucial to identify features that accurately represent a clash and also represent the factors industry experts consider when resolving the clash. Along with features, labels need to be selected as well to represent clash resolution options available to the industry. To achieve this in chapter 2 the author using modified Delphi captured the domain knowledge that industry experts utilize to resolve clashes. Factors considered by industry experts to decide on how clashes are resolved and options to resolve clashes are extracted from the domain knowledge. As a result of this research, the author identified 23 factors that industry experts consider when resolving clashes and 5 options available to resolve the clash. The work concludes by identifying factors and options that can serve as features and labels for a machine-learning algorithm to automate clash resolution. Once features and labels are identified the author in chapter 3 discusses the development of a prediction model to predict clash resolution options for a given clash. The discussion is focused on individual steps involved in the creation of machine learning models like data collection, data pre-processing, and machine learning algorithm development and selection. The author also addresses common challenges in the development of machine learning models like class imbalance and availability of limited data. The author utilizes a multi-label synthetic oversampling method (MLSOL) to generate different percentages of synthetic data to account for class imbalance and limited datasets. Using this dataset, the author then trained five different supervised learning algorithms and reported their accuracy. Based on this work the author concluded that increasing the dataset with 20% of synthetic data and using an artificial neural network to develop the machine learning model to automate clash resolution generated the best result with an average accuracy of around 80%. To address the limitation of using only supervised learning and as a second contribution to the body of knowledge, the author in chapter 4 proposes the use of reinforcement learning to train a Deep Q Network (DQN) agent capable of learning how to resolve clashes through interactions with a Building Information Model (BIM) environment containing clashes. The work discusses the implementation of a dynamic reward function to guide the agent in making decisions based on industry best practices. Additionally, it outlines the setup of the interaction between the agent and the environment to facilitate learning. Considering that reinforcement learning requires a significant amount of time to develop knowledge, the author also tested the effect of using a pre-trained supervised learning model to initialize the reinforcement learning policy function and guide knowledge exploration. This approach resulted in three variations of supervised-reinforcement learning. The supervised learning model used in this research demonstrated an accuracy of 31%. To demonstrate the utility of reinforcement learning in training an agent, the authors plotted graphs showing the number of clashes resolved per episode and the cumulative reward received per episode. The clashes resolved by the agent in this research were limited to clashes between ducts and pipes. These graphs illustrated that with each successive episode, the agent became increasingly proficient at resolving clashes. Among the variations of supervised-reinforcement learning, the one that exhibited the most stable learning graph utilized the weights of the supervised learning model to initialize the policy function of reinforcement learning. This research confirmed that reinforcement learning can be employed to train an automated model instead of relying solely on supervised learning, especially in scenarios where limited or no clash resolution data is available. Moreover, pre-training reinforcement learning using a supervised learning model led to more consistent learning outcomes. The research presented in this dissertation focuses on the holistic development of a machine learning model to automate clash resolution. By identifying appropriate features and labels before training the model the author ensures that the automation model accurately captures industry best practices and is explainable. Furthermore, by utilizing a systematic approach towards the development of a machine learning model the author addresses common challenges in developing a machine learning model and how we can overcome them. Lastly, through the utilization of supervised reinforcement learning the author proposes an alternative learning algorithm that can learn how to resolve clashes with fewer labeled examples through Building Information Model (BIM) interaction and with a more steady learning rate than reinforcement learning alone.	en
dc.description.abstractgeneral	Clash Coordination is a crucial step in ensuring timely and cost-effective project delivery. While software tools like Navisworks and Solibri have improved the process of aggregating models and conducting clash tests and categorization, resolving clashes remains a slow and manual task. The reason for this slow process can be attributed to the meticulous nature of the process where design coordinators need to make sure that resolving one clash does not lead to the creation of new clashes. Research has been conducted to improve the clash coordination process through automation using supervised learning, where a machine is taught to resolve clashes by understanding existing examples of clash resolutions. However, these researches do not provide enough evidence on how the example of clashes are presented to the machine and skip the details on common challenges associated with machine learning and how to overcome them. Also, as these researches focuses on training a machine using existing examples of clash resolution, a large number of examples are required to develop an effective machine-learning solution. The author of this dissertation addresses these limitations and contributes to the body of knowledge. In Chapter 2 the author discusses the use of modified Delphi to capture the industry's knowledge on how to make decisions about clash resolution and what options to consider when resolving clashes. The author also took measures during this process to reduce biases like intercoder reliability checks to make the results of modified Delphi more accurate. As a result of modified Delphi, the author identified 23 factors that industry experts consider when resolving clashes and 5 options available to resolve the clash. These identified factors and options were later utilized by the author in chapter 3 as features and labels to represent clash resolution examples. Using these examples, the author then developed a supervised learning model able to predict the most likely solution for a given clash with 80% accuracy. While developing the supervised learning model the author discusses common challenges associated with machine learning like class imbalance, data scrubbing, and un-normalized data and their mitigative measures. To address the limited availability of clash resolution examples the author in chapter 4 proposes and develops a supervised-reinforcement learning model. This model teaches how to resolve clashes by continuously interacting with a BIM model. To improve the learning rate the model also utilizes the knowledge gained through the development of a supervised learning model. This research shows that using reinforcement learning it is possible to train a machine to resolve clashes and adding knowledge from supervised learning to reinforcement learning results in a steadier learning rate for the machine. The research also shows that a more accurate supervised learning model can be developed using limited clash resolution examples using deep artificial neural networks, though this kind of approach increases the learning time and can lead to the issue of overfitting.	en
dc.description.degree	Doctor of Philosophy	en
dc.format.medium	ETD	en
dc.identifier.other	vt_gsexam:41541	en
dc.identifier.uri	https://hdl.handle.net/10919/121210	en
dc.language.iso	en	en
dc.publisher	Virginia Tech	en
dc.rights	In Copyright	en
dc.rights.uri	http://rightsstatements.org/vocab/InC/1.0/	en
dc.subject	Machine Learning	en
dc.subject	Clash Resolution	en
dc.subject	Supervised Learning	en
dc.subject	Reinforcement Learning	en
dc.subject	Feature Engineering	en
dc.subject	Data Preprocessing	en
dc.subject	Design Coordination	en
dc.title	A Supervised-Reinforcement Learning Model for Automated Clash Resolution in the Construction Industry	en
dc.type	Dissertation	en
thesis.degree.discipline	Environmental Design and Planning	en
thesis.degree.grantor	Virginia Polytechnic Institute and State University	en
thesis.degree.level	doctoral	en
thesis.degree.name	Doctor of Philosophy	en