Multi-Agent Framework for General-Purpose Situational Simulations in the Construction Management Domain

The need for contextually rich education environments in construction management suggests the development of a general-purpose situational simulation framework that can be used by independent developers to build effective training environments. Design and implementation of such a framework involves an understanding of the reasoning processes underlying the construction management domain. These reasoning processes can be isolated using a conceptual classification of problems in the construction management domain into constraint satisfaction and planning. Such a classification allows us to distribute the different reasoning processes to autonomous agents that comprise the foundations of a multi-agent framework for building general-purpose situational simulations. The Virtual Coach is an implementation of the proposed framework. Experimental results from preliminary studies have shown the efficacy of the Virtual Coach as an educational tool.     

Interval Temporal Logic in General-Purpose Situational Simulations

The need for contextually rich educational environments in construction engineering and management calls for the development of situational simulations. Situational simulations emulate real processes and provide temporally dynamic clinical exercises that expose participants to rapidly unfolding events and the pressures of decision making. A survey of simulations of construction management processes and construction operations shows that commonly used discrete event simulation paradigms are unsuitable for representing actions and events in interactive general purpose situational simulations for the construction domain. Instead, this paper argues that a definition of the situational environment using the semantics of constraint satisfaction and an interval representation of time is more appropriate for representing activities, events, actions, and situations relevant to the construction domain. This paper also illustrates how this new paradigm facilitates the implementation of a reasoning mechanism that can be used by a software agent to perceive present actions and predict the future evolution of a simulated environment.     

Integrated Schedule and Cost Model for Repetitive Construction Process

Several efforts have been made by many researchers to develop a model for schedule and cost integration in construction projects, but it is difficult to integrate and manage schedule and cost in an actual construction site using such a model. The integrated schedule and cost model developed in this study (1) enables the planning and control of repetitive construction processes and (2) can be used by a project manager in an actual construction site. Furthermore, an integrated schedule and cost model for the core wall construction, which is an important repetitive process in the recently booming high-rise building construction in terms of scheduling, was developed using the integration model developed in this study. It is expected that the integrated schedule and cost model developed can allow project managers to integrate the schedule and cost of repetitive construction processes more effectively and support the project managers’ decision-making.     

Activity Object-Oriented Simulation Strategy for Modeling Construction Operations

The application of an object-oriented (OO) approach including the OO modeling concept and the OO programming mechanisms to develop an activity object-oriented (AOO) simulation strategy for modeling construction operations is introduced. After discussing simulation strategies generally used for construction simulation and analyzing the problems related to the simulation strategies, the AOO simulation strategy that guides modeling or controls simulation experiments for construction simulation is introduced. The AOO simulation strategy considers activities to be objects and is able to overcome some pitfalls that result from other general simulation strategies. In addition, the AOO graphical modeling interface associated with the AOO simulation strategy is described. Finally, comparisons of the graphical model or the simulation results of the AOO simulation system with other simulation tools are illustrated.     

Research in Modeling and Simulation for Improving Construction Engineering Operations

Construction simulation, a fast-growing field, is the science of developing and experimenting with computer-based representations of construction systems to understand their underlying behavior. This paper provides a history of construction simulation theory, explores the CYCLONE modeling methodology and its major subsequent developments, examines the development of the Simphony.NET and COSYE modeling environments and their functionality as more generic simulation platforms, and reviews effective strategies for applying simulation in construction. A construction simulation case study is presented that illustrates one successful approach for adopting simulation technology in the industry and outlines the benefits to industry of integrating these technologies. The paper provides an overview of long-term simulation initiatives leading to the next generation of computer modeling systems for construction, where simulation plays an integral role in a futuristic vision of automated project planning and control.     

Decision Tree Modeling Using Integrated Multilevel Stochastic Networks

Decision trees (DTs) have proven to be valuable tools for decision making. The common approach for using DTs is calculating the expected value (EV) based on single-number estimates, but the single-number EV method has limited the DTs’ real-life applications to a narrow scope of decision problems. This paper introduces the stochastic multilevel decision tree (MLDT) modeling approach, which is useful for analyzing decision problems characterized by uncertainty and complexity. The MLDT’s advantages are shown through a computer simulation program: the Decision Support Simulation System (DSSS). The DSSS allows users to model probabilistic linear graph networks and provides a hierarchical modeling method for modeling decision trees to present uncertainties more accurately. It consists of three modules: tree analysis networks (TANs), the shortest and longest path dynamic programming analysis network, and cost time analysis networks. The paper only discusses the TAN module by presenting the MLDT concept under the TAN of the DSSS computer application. The content of the paper includes the modeling approach, its advantages, and examples that can be used in modeling stochastic trees. The DT-DSSS was verified by conducting several tests and validated by using it extensively for undergraduate courses in civil engineering at the University of Calgary for the last two academic years.     

Construction Engineering Requirements for Integrating Laser Scanning Technology and Building Information Modeling

Laser scanning for rapid spatial data acquisition is an established technology in the architecture, engineering, and construction (AEC) sector with a wide range of applications. An understanding of the wide variation of technical requirements and considerations associated with these applications is critical to decision making about laser-scanning implementation on projects. Furthermore, significant industry transformations in the use of building information modeling present extraordinary opportunities for AEC professionals to employ the use of laser scanning in the context of holistic, collaborative workflows grounded in three-dimensional model-based design. This report analyzes the construction engineering requirements of laser scanning technology for applications across all phases of the project life cycle and proposes a multidisciplinary framework to integrate applications of laser scanning technology with the fundamentals of three-dimensional model-based design.     

Fuzzy Approach to Prequalifying Construction Contractors

Construction contractor prequalification (CCPQ) is a crucial decision making process to select capable potential bidders and ensure the success of construction projects. The purpose of CCPQ is to guarantee a contractor’s characteristic to meet the construction project’s requirements, which has been established worldwide as a standard practice. However, existing methods, i.e., marking method, subjective judgment method, etc., for contractor prequalification have been inadequate because it is difficult for decision makers to investigate contractor’s capabilities against inexact, vagueness, and qualitative criteria. The objective of this paper is to propose a fuzzy framework-based fuzzy number theory to solve construction contractor prequalification issues, which include decision criteria analysis, weights assessment, and decision model development. Finally, a case study for a tunnel construction project was used to demonstrate the feasibility of fuzzy approaches.     

Role of Simulation in Construction Engineering and Management

Construction simulation is the science of developing and experimenting with computer-based representations of construction systems to understand their underlying behavior. This branch of operations research applications in construction management has experienced significant academic growth over the past two decades. In this paper, the author summarizes his views on this topic as per his Peurifoy address, given in October 2008. The paper provides an overview of advancements in construction simulation theory as reported in literature. It then summarizes the key factors that contribute to successful deployment of simulation in the construction industry, and the key attributes of problems that make them more amenable for simulation modeling as opposed to other tools. The paper then provides an overview of long-term simulation initiatives leading to the next generation of computer modeling systems for construction, where simulation plays an integral role in a futuristic vision of automated project planning and control.     

Analytic Network Process Applied to Project Selection

Owing to the complexity of a construction project, the analytic network process (ANP) is helpful to deal with interdependent relationships within a multicriteria decision-making model. This paper demonstrates an example to illustrate how to empirically prioritize a set of projects by using a five-level project selection model. A questionnaire was filled by a group of construction professionals of a medium-sized local developer and scores were computed for prioritizing the potential projects. The paper is relevant to both industry practitioners and researchers. Industry practitioners may adopt the weighted criteria for direct project selection or apply the ANP method to prioritize their own set of selection criteria. Researchers may rely on this paper as a point of departure for exploring other uses of ANP.     

Using Group Decision Support System to Support Value Management Workshops

A group decision support system (GDSS) is an interactive computer-based information system that combines the capabilities of communication technologies, database technologies, computer technologies, and decision technologies to support the identification, analysis, formulation, evaluation, and solution of semistructured or unstructured problems by a group in a user-friendly computing environment. As there is a strong demand for improvements to the practice of value management (VM), research has been conducted to design a GDSS prototype system, named the interactive value management system (IVMS), to explore its potential application in VM workshops and to investigate the effect of the application. The paper begins with an introduction to the problems of implementing VM in the Hong Kong construction industry and then proceeds to an illustration of the features of the proposed system, which has been developed in the research. Two validation studies designed to test the support of the proposed system are described and the results discussed. Findings from this research indicate that IVMS is supportive in overcoming the problems and difficulties in VM workshops.     

Optimal Project Organizational Structure for Construction Management

This study relies on the trend model to investigate various modes of coordination among team members of construction projects. According to the project network developed based on the characteristics of a project, the trend model establishes an activity relationship matrix (ARM) to identify the activity relationships within the construction process. ARM is used to construct an organizational structure for project management and a communication resistance matrix that shows the efficiency of communication and coordination among the members of the project team. To evaluate various organizational structures and their coordination efficiencies, this study utilizes the analytical hierarchy process to quantify the strength of an organizational structure and identify the optimal structure for project management. Through quantitative modeling of communication efficiency among organizational team members, an objective function for calculating the total resistance index is used to determine the optimal organizational structure available to execute the project. This study demonstrates how the trend model may be applied in the future for evaluating the coordination efficiencies of various organizational structures.     

Engineering-Based Decisions in Construction

This paper uses four case studies to emphasize the fact that field engineering decisions cannot be made without a full understanding of all the technical problems involved. Two of the studies are taken from conventional design-bid-build projects and two are taken from design-build projects in which the ability to strongly influence design in the interest of construction efficiency places a new and increased emphasis on construction and field engineering skills. The cases also show that field engineering decisions frequently address new and unexpected realities, changed conditions, and transient loads, and thus they require high levels of understanding, technical analysis, and creative thought. We emphasize the need for universities and construction engineering programs to develop graduates who are capable of integrating design and construction considerations throughout the project delivery process. We also urge programs to continue to focus strongly on field engineering as the foundation for success in an increasingly complex and technically driven construction industry.     

General-Purpose Situational Simulation Environment for Construction Education

The traditional construction education model based on precise well-defined problems and formal definitions is not satisfactorily fulfilling its mission of educating the decision makers of tomorrow. This realization has moved several researchers to explore alternatives where problem solving is carried out in conjunction with the environment, and concepts are embedded in the context promoting learning within the nexus of the activity. Several efforts have been undertaken to develop these environments resulting in a variety of special-purpose situational simulations. However, special-purpose situational simulations exhibit inherent limitations related to their application breadth, flexibility, and promotion of collaborations. These limitations cannot be resolved within the framework of special-purpose learning environments. A general-purpose environment is required to overcome these shortcomings and take full advantage of the situational learning paradigm. This paper describes the conceptual framework and pilot implementation of such an environment called the Virtual Coach.     

Embodying Product and Process Flexibility to Cope with Challenging Project Deliveries

Four factors make it challenging to manage semiconductor fabrication facility (“fabs”) projects: technical complexity of the product design, need to compress the project duration, need to reduce upfront costs, and unexpected project changes. The strategies employed by practitioners to cope with these challenges form an intricate puzzle. We empirically develop a framework that provides a structure for helping to solve this puzzle, which comprises two principles: investing upfront in a flexible product design and structuring a flexible process. Empirical findings reveal that project teams make commitments early on by overdesigning but also postpone critical decisions by differentiating the scope of their work. Project teams employ other strategies such as increasing communication, using modular architectures, engaging in four-dimensional computer-based modeling, and fabricating components and subsystems off-site. Our analysis yields understanding on the purposes and performance tradeoffs of these strategies, and on how they embody the two principles. Project managers may find the framework useful when deciding which strategies best suit other equally challenging projects.     

Excavation Game: Computer-Aided-Learning Tool for Teaching Construction Engineering Decision Making

This paper reports on an interactive computer-aided-learning (CAL) tool that was developed for the education of construction engineering students: the excavation game. It builds on the large potential of using CAL in education. CAL tools could offer a better learning environment for students, as they provide an excellent opportunity for applying and testing the management skills learned in classroom, but are difficult to implement in reality. In this research, the CAL tool focuses on improving students’ decision-making skills in the aspects of excavation and related activities. These are excavation equipment, dewatering, and soil-support methods. It also covers mobilization, surveying, safety, overtime shifts, and reporting. Students compete with regard to time, cost, and quality of construction of a given project. The game flow is nonlinear as it depends on students’ decisions. Wrong decisions deviate the construction flow to a path that costs money and time, while reducing quality. This must be corrected costing extra money and time. The game was tested by senior practicing engineering and university professors. Then, it was tested by senior undergraduate construction students. Both groups agreed that the game responds, to a great extent, to the characteristics of effective CAL software, and that the information provided could not be easily assimilated or practiced through the usual tutorial or demonstration educational format. 18% of the professionals and 72% of students indicated the usefulness of the game in applying management and decision-making skills. 60–70% of students believed that it improved their technical skills in dewatering, soil-support, and excavation activities. In addition, 80% of the professionals found the game presenting realistic soil-support and excavation situations, while 72% of students became more appreciative of the interdependencies between activities.     

Process Model for Administrating Construction Claims

Claims for additional costs and time extensions result from a variety of events occurring during the course of construction. To enhance the chances of success, contractors submitting claims must closely follow the steps stipulated in the contract conditions, provide a breakdown of alleged additional costs and time, and present sufficient documentation. On the other hand, project owners need to follow an overall comprehensive step-by-step procedure for tracking and managing the claims submitted by contractors. The paper presents a claims-management process that could be used by all parties involved in construction. The process identifies the major information-gathering and decision-making milestones as well as the notice and substantiation compliance checkpoints, which are critical to the development of defense arguments as claims are addressed. It further emphasizes the use of tools such as simulation, scheduling, productivity, and economic analysis and other modeling techniques in judging the level of justification and reasonableness of submitted claims.     

AHP-Based Equipment Selection Model for Construction Projects

Selection of equipment for construction projects, a key factor in the success of the project, is a complex process. Current models offered by the literature fail to provide adequate solutions for two major issues: the systematic evaluation of soft factors, and the weighting of soft benefits in comparison with costs. This paper presents a selection model based on analytic hierarchy process (AHP), a multiattribute decision analysis method, with a view to providing solutions for these two issues. The model has the capacity to handle a great number of different criteria in a way that truly reflects the complex reality, to incorporate the context and unique conditions of the project, and to allow for manifestation of user experience and subjective perception. The model was implemented in an in-house developed system that was improved and validated through testing by senior professionals. The main academic contribution of the study is in the modification of AHP to correspond with the nature of equipment selection and in its utilization as an effective means for the formalization of knowledge possessed by competent, experienced practitioners. On the practical side, the proposed model offers an efficient, convenient tool that forces the users into orderly, methodical thinking, guides them in making logical, consistent decisions, and provides a facility for all necessary computations.     

Modeling of Functional Construction Requirements for Constructability Analysis

Evaluating construction requirements should be an indispensable part of improving the constructability of a facility project. However, a number of existing function analysis approaches focus mainly on the final functions with respect to the finished facility. The construction industry still lacks methodologies to represent and evaluate the functional construction requirements for constructability analysis. This paper develops the concept of intermediate functions for representing the construction requirements from three perspectives, namely, function user, function provider, and the temporal and spatial relationships between the user and the provider. This is followed by the development of an in-progress product model to abstract the construction lifecycle of a facility product utilizing the concept of component state. Furthermore, the reference relationships among such perspectives as in-progress product, intermediate function, resource, and process are addressed. Based on these reference relationships, the bottleneck states for providing the intermediate functions can be detected. A case study of constructing the deck of a bridge using the balanced cantilever approach is presented to illustrate the utilization of this concept and representation.     

“Soft” Considerations in Equipment Selection for Building Construction Projects

This paper raises the issue of “soft” considerations in the selection of equipment for building construction projects. The paper aims at increasing the awareness: (1) to the nature, variety, and richness of soft factors; (2) to their significant role and potential impact on the outcome of decision making; and (3) to the inherent difficulty of evaluating them and integrating them within a comprehensive selection process. Existing state-of-the-art equipment selection models were analyzed and found to be inadequate in terms of both considering soft factors and providing mechanisms for their systematic evaluation. Six cases of large-size, complex construction projects were investigated to obtain an extensive list of typical soft factors. This investigation revealed that the consideration of soft factors in current practices is essentially unstructured and is not integrated within the selection process in a systematic manner. A desirable selection process is outlined that generally responds to the needs identified in the study. The proposition of a specific method for the quantitative treatment of soft factors and their tradeoff with cost factors is the subject of another paper.