Koshy Varghese

Researchers have identified the dependency structure matrix (DSM) as a potential tool to explicitly identify iteration blocks and to evaluate the resulting sequence. Factors such as duration of activity, duration of rework, location of feedback variables, size of block, and number of loops within a block influence the overall duration of a project. The present study traces a pattern underlying the behavior of the block in evaluating the execution sequence. To achieve this objective, a database is generated for two-activity and three-activity DSMs by using a Monte-Carlo simulation based approach. The results of the model are analyzed to determine the placement of activity and rework probabilities that can achieve minimal duration of a project. © 2014 American Society of Civil Engineers.

Progress quantification of construction projects is critical for project managers to manage projects effectively. The trade-off between computation time and accuracy is a key aspect while selecting the quantification method. Though accuracy is essential, project managers require real-time information about quantities of work completed on various building components to make timely decisions. Several researchers have developed individual pipelines using vision-based technologies for automated progress quantification. However, they face significant implementation challenges, including higher computational complexity, skilled personals, and costly equipment. Hence, this study aims to define an easy-to-implement pipeline to quantify the holistic progress and element-wise progress of a building. For executing this, the method utilizes point intensity as a fundamental parameter. The progress of a specified element is calculated by comparing the number of points in the as-built model and the number of anticipated points from the as-designed model of the same point intensities. The method directly integrates the as-designed BIM model with the scan data through a user-friendly visual programming tool - Grasshopper3D for progress quantification. The workflow provides one-click progress report generation with minimal inputs from the users for basic alignment of the imported as-built data. As the point clouds are directly addressed as a single entity, and to-be intensity has been calculated through an intensity-based randomized approach, the method utilizes less computation for the whole process.

Dependency structure matrix (DSM) concepts have been applied effectively to represent and manage complex design processes. However, the author's attempts to implement the concepts on large construction projects faced limitations. The key limitation was that the identification of elements for activity DSM at the appropriate level of abstraction required significant levels of expertise. As drawings are well-defined entities that are directly identifiable by the design team, this paper proposes that drawing DSM (DDSM) be used to manage the design process. Further, as drawing production is a complex task containing many subactivities, a structured method is required to identify the dependencies between the drawings. Based on a systems approach, a three-stage structured methodology to decompose the project and identify the drawing interfaces is developed. The conceptual details of this methodology are explained and the steps are illustrated using a generic example. The paper also presents the application of the methodology to an airport project and discusses the results obtained as well as the necessary future improvements. © 2009 Earthscan.

Though it is well established that coastal zones are development sensitive with its variety of resources and multiple stakeholder presence, (Clark.J.R. 1997) there is no holistic metric to measure this sensitivity. This paper encapsulates the outcome of a doctoral level work to evolve a set of indicators named Coastal zone Health Indicators (CHIs) as metric for this purpose. CHI looks upon a coast as composed of its 6 core component environments and coastal zone health is holistically reflected by the value of critical parameters pertaining to specific component environments. CHIs are developed based on an extensive nation wide experts' survey conducted across major coastal cities in India. Though the study is confined to experts chosen from Coastal cities of India, the generic framework it evolves is globally valid. Analytical Hierarchical Processing (AHP) based weightages of parameters as extracted from the expert survey are used in these models. The paper covers the conceptual basis and methodology of developing CHI. With a CHI map in place for a coastal city, constantly monitoring and evaluating CHI variations against set goals provide valuable feedback on the implementation efficiency of ICZM process. It also helps in analysing future landuse allocations for their impacts on the CHI profile. This practice ensures landuse planning to be a meaningful exercise always tested for synergy with ICZM measures and thus ensuring sustainability in the long run.

Project schedules play a critical role in managing a project’s time performance. Network-based techniques such as the Critical Path Method (CPM) and its extension, the Precedence Diagramming Method (PDM) are widely used for project scheduling. Planning engineers have reported several cases where intricate schedule networks are developed to plan a project, however, these are not useful for managing the project as the details of the project are not accurately represented in the network. Schedules that cannot be used effectively for managing projects are termed to be of poor quality. As projects get more complex and demanding, the need for objectively assessing schedule quality has become important. To address this need, assessment guides/standards have been developed by client agencies such as United States Government Accountability Office as well as professional organizations such as the Project Management Institute (PMI) and Association for Advancement of Cost Engineering (AACE) International. These standards specify qualitative and quantitative guidelines to conform to the standard, and schedules that do not meet the guidelines are non-conformant schedules. Further, specific areas of non-conformances can be assessed, and changes can be made to conform to the guidelines. While assessing schedules against a standard guideline enables identifying areas of non-conformances for a specific schedule, there has been no systematic study to evaluate the patterns of non-conformance across baseline schedules. Further, there has been no work that has identified the causes of these non-conformances. Identifying the causes can enable preventive action to be taken rather than corrective action. This study addresses these gaps by first assessing the conformance of baseline schedules of thirty sample projects using standard guidelines and quantifying the categories of non-conformance across projects. As the assessment guidelines are both quantitative and qualitative, three types of assessment mechanisms are utilized to identify the non-conformances. Next, causes for non-conformances are identified using document review followed by semi-structured interviews with twenty-three experts. The root causes underlying the immediate causes for schedule non-conformances were derived using Root Cause Analysis (RCA) methodology and the impact of the root causes on the non-conformances was assessed. The root causes and their impact were verified through a modified Delphi study involving a second set of experts and strategies to address the root causes are discussed.

Tunnels are subterranean conveyance systems. Historically tunnelling projects have suffered significant cost and time overrun on account of variation in geological formation. Variation in strata may lead to various problems like tunnel caving in, water seepage etc. An attempt has been made to extend the Q-system of rock mass classification for reliable prediction of these tunnelling problems. For the purpose tunnelling problems have been identified and classified. A computer tool has been developed to aid the process. Also simulation as an aid for time planning while tunnelling under such varying geological conditions has been investigated. Reliable estimates of tunnelling problems and effect of geological variations on the project schedule will help the project management in informed decision making as regards issues like resource requirement. This paper describes the compilation and classification of tunnelling problems, matching problems to the Q-system parameters and the simulation model developed.

Management of a construction project is challenging due to the unique nature of each project. Even though the project itself is unique, the activities within it are generally repetitive. Network techniques which were developed for overall management of projects are not appropriate for detailed planning as they are highly abstract representation of the actual project activities. Simulation has the potential to be used for detailed planning as it permits the modelling of cyclic activities and uncertainties, such as, variations in duration and occurrences of probabilistic events, such as, equipment breakdown. The objective of this study is to investigate the application of discrete event simulation as a tool for detailed planning of repetitive construction processes. As a part of the investigation, CPM and simulation models representing the girder casting and placing activities a of bridge construction project was developed. Two alternate construction processes were modelled using the techniques. The models were tested by varying the resource levels and factors, such as, duration of project. Utilization of key resources were assessed. The results obtained are presented and discussed. It was found that the simulation is a useful tool for detailed planning of repetitive construction activities.

Generating as-is 3D Models is constantly explored for various construction management applications. The industry has been dependent on either manual or semi-automated workflows for the Scan-to-BIM process, which is laborious as well as time taking. Recently machine learning has opened avenues to recognize geometrical elements from point clouds but has not been much used because of the insufficient labeled dataset. This study aims to set up a semi-automated workflow to create labeled data sets which can be used to train ML algorithms for element identification purpose. The study proposes an interactive user interface using a gaming engine within a mixed reality environment. A workflow for fusing as-is spatial information with the AR/VR based information is presented in Unity 3D. A user-friendly UI is then developed and integrated with the VR environment to help the user to choose the category of the component by visualization. This results in the generation of an accurate as-is 3D Model, which does not require much computation or time. The intention is to propose a smooth workflow to generate datasets for learning-based methodologies in a streamlined Scan-to-BIM Process. However, this process requires user domain knowledge and input. The dataset can be continuously increased and improved to get automated results later.

Reassembling hand shredded content-less pages is a challenging task, with applications in forensics and fun games. This paper proposes an efficient iterative framework to solve apictorial jigsaw puzzles of hand shredded content-less pages, using only the shape information. The proposed framework consists of four phases. In the first phase, normalized shape features are extracted from fragment contours. Then, for all possible matches between pairs of fragments transformation parameters for alignment of fragments and three goodness scores are estimated. In the third phase, incorrect matches are eliminated based on the score values. The alignments are refined by pruning the set of pairwise matched fragments. Finally, a modified graph-based framework for agglomerative clustering is used to globally reassemble the page(s). Experimental evaluation of our proposed framework on an annotated dataset of shredded documents shows the efficiency in the reconstruction of multiple contentless pages from arbitrarily torn fragments.

Today several activities of a construction project can be supported with information technology tools. However, there have been many cases of technology adoption failure. Lack of understanding about the process of technology adoption is often pointed out as the reason. This paper is based on a study to explore BIM technology adoption process and attempt to model and evaluate the process using system dynamics. The paper has its base on literature survey and five month field studies of three construction projects where BIM was being introduced. Insights from literature survey and case studies were used to develop a core system dynamics model of technology adoption. To this core, project and technology specific data was added to develop a preliminary system dynamics model. The research indicates that system dynamics is a promising approach in improving our understanding of technology adoption in construction projects.