Temporal Logic Representation Schema for Intermediate Function

There are temporal relationships other than the precedence ones between construction activities. Many of these relationships are related to the perspective of intermediate function requirement. The construction industry still lacks a representation schema for capturing the temporal logics residing in this kind of construction requirement. This study presents a schema for representing these temporal logics from three perspectives, namely the construction life cycle of a single product component, the functional interdependencies between two in-progress components, and the availability conditions of an intermediate functionality. In this way, the concurrency relationships among the construction processes can be identified and evaluated, and the intermediate function analysis can be conducted more efficiently, thus contributing to improvement of the executability of construction schedules. Additionally, the temporal logics have been formulated in the format based on temporal interval algebra, which provides a richer semantic representation compared to the traditional precedence relationship types. Finally, using a four-dimensional simulation prototype, a case study of constructing the deck of a bridge by the balanced cantilever approach is modeled to demonstrate the representation of the three perspectives of intermediate function requirements.     

Incorporating Maintainability in Constructability Review Process

Life cycle cost or total cost analysis of a facility begins with the initial design concept and ends with the decommissioning of the facility. Decisions made during the design and construction phases routinely consider only the construction costs when analyzing the constructability of the project. Often the impacts of such decisions on the maintenance requirements for the facility are not fully appreciated and are therefore not formally addressed. The concept of “maintainability” addresses this concern and is a logical extension of the constructability concept. As such, maintainability may be incorporated as a part of the formal constructability review process (CRP). This article describes a model format for incorporating the best practices for maintainability into the CRP. The added life cycle value of incorporating maintainability into the CRP can only be assessed by analysis of accurate and complete maintenance cost data. Insights from such an analysis may facilitate more accurate estimates of the total costs of facilities.     

Integrating Constructability into Project Development: A Process Approach

The National Cooperative Highway Research Program initiated a research project to develop a constructability review process (CRP) for transportation facilities. The basic objective of this research was to develop a systematic approach and methodology for constructability reviews. This paper describes the development of a CRP that meets the National Cooperative Highway Research Program's research objectives. A process approach is followed to integrate constructability improvements into project development for transportation projects. A function modeling tool is used to portray the interface between the CRP and the project development process. The function modeling tool captures constructability functions and information necessary to perform these functions. The research method to develop the CRP is presented. The CRP has three phases corresponding to planning, design, and construction of a transportation project. Seven constructability functions are performed in each phase. The model was tested using two transportation projects of different complexity.     

Constructability Practices among Construction Contractors in Indonesia

The concept of constructability in the United States or buildability in the United Kingdom emerged in the late 1970s, which evolved from studies into how improvement can be achieved to increase cost efficiency and quality in the construction industry. It is an approach that links the design and construction processes. The studies in the Unites States, United Kingdom, and Australia have demonstrated that improved constructability has lead to significant savings in both cost and time required for completing construction projects. However, in implementing constructability improvement, it is important to consider the uniqueness of the construction industry in a specific country. This paper presents the study performed on the construction contractors in Indonesia with regard to their current constructability practices and its impact on the project performance. The study shows that many contractors in Indonesia have been implementing part of the constructability concept in their projects. The concepts that usually applied during the construction stage as part of the overall construction plan were planning the sequence of field tasks and analyzing layout, access, and temporary facilities     

Computer-Based Application for the Processing of Clients' Requirements

This paper extends previous work on the use of quality function deployment for client requirements processing in construction. It describes a computer-based application, ClientPro, which implements a quality-function-deployment-based model for the definition, analysis, and translation of client requirements into solution-neutral design specifications. The methodology, development, operation, and evaluation of the prototype are discussed, and it is concluded that ClientPro is useful in facilitating the systematic definition, analysis, and mapping of client requirements to design specifications. It also provides for the incorporation and prioritization of the perspectives represented by clients, the determination of the relative importance of their requirements, and the early consideration of life-cycle issues affecting a facility. Thus, it can contribute to the ultimate satisfaction of the requirements of construction clients.     

Constructability Rankings of Construction Systems Based on the Analytical Hierarchy Process

This paper uses the quantitative decision-making technique, the analytical hierarchy process, to derive prioritized scales for (1) the constructability factors; and (2) the relative contribution of common construction systems in a building superstructure comprising structural frames, slabs, envelopes, roof, and internal walls toward constructability. The identified constructability factors show that to enhance constructability design requirements should be easily visualized and coordinated by site staff, while designs should allow economic use of contractors’ resources and enable contractors to develop and adopt alternative construction details. The precast method is rated as the most constructible construction method, indicating its better performance in facilitating efficient and safe construction in the busy urban environment in Hong Kong. However, the methodology adopted in this study should be of international interest, especially for those desirous of improving constructability of designs with different contextual backgrounds.     

Constructability State of Practice Report

This report reviews guidance on constructability programs from a variety of sources and presents the current practice of constructability. The advice of several organizations and researchers is summarized to describe expectations for ideal constructability. Actual current constructability practice, based on results and analysis of a Constructability State of Practice survey, is described. Approximately 100 owners, architects, engineers, consultants, contractors, and construction managers answered the survey’s ten questions and provided written comments. The results provide a picture of current constructability practices in the architecture, engineering, and construction (AEC) industry and progress in recent years. Major conclusions include: (1) constructability has gained acceptance throughout the industry; (2) constructability efforts are clearly beginning in early project phases; (3) a wide variety of constructability techniques and new technologies are being implemented; and (4) obstacles to improving constructability remain, but may be changing. Finally, recommendations are provided based on areas where constructability practice can still be improved. This report is relevant to both industry practitioners and researchers.     

Constructability Analysis of the Bridge Superstructure Rotation Construction Method in China

Constructability analysis can provide valuable input to optimizing urban bridge construction in terms of reducing impacts on traffic, safety, and overall project budget and duration. This paper presents a constructability analysis of the superstructure rotation method for bridge construction. The method includes building the bridge parallel to the obstacle being overpassed (a river or a highway) and then rotating the superstructure into place. The method has been used successfully in over one-hundred bridges (mostly in China). The paper documents two case studies of bridges that used this method and provides an analysis of the constructability of the method. This includes identification of the factors influencing the constructability of the methods and lists of design and construction objectives/strategies that support the constructability of bridges using this method.     

Scorecard Approach to Benchmarking Organizational Safety Culture in Construction

This paper promotes adopting the balanced scorecard tool to benchmark organizational safety culture in construction. It argues that this tool has the potential to provide a medium to translate the organization’s safety policy into a clear set of goals across four perspectives: management, operational, customer, and learning. These goals are then further translated into a system of performance measures that could effectively communicate a powerful strategic focus on safety to the entire organization. Four perspectives have been developed to represent all stakeholders, thereby ensuring that a holistic view of safety is used for strategic reflection and implementation. The paper argues that by selecting and evaluating the appropriate measures, in each perspective, requirements can be identified, and actions to the identified goals can be aligned and facilitated. The proposed balanced scorecard approach should therefore enable construction organizations to pursue incremental safety performance improvements. Work-in-progress is briefly reported to give insight into the potential applicability of this approach.     

Acute lymphoblastic leukemia in children. Progress in life expectancy

Heuristic construction knowledge generated while contracting is seldom recorded and transferred to other workers. Experiences of past mistakes as well as efficient work practices are crucial means for saving money, time, and improving the safety and quality of construction. With the rising costs of construction and the increased demand of time constraints on contractor schedules, few members of the construction industry can afford to waste time and resources on errors or ineffective work practices. The Constructability Lessons Learned Database (CLLD) prototype described in this paper is a leading edge method of automatically gathering, systematically organizing and efficiently applying vital construction information to a contractor's daily activities. This paper presents a review of previous and current attempts at database constructability programs, uses of constructability feedback systems, challenges to develop and utilize such systems, and an overview of the design and development of the CLLD prototype. The overview describes knowledge elicitation techniques used to gather constructability knowledge, the design of the system (organizing and classifying construction information for efficient retrieval and expansion), and system's implementation, validation, and operation. The conclusion discusses future extensions of the CLLD concept in the construction industry.     

Constructability Concepts in West Port Highway in Malaysia

This paper presents a case study of the applications and nonapplications of constructability concepts to illustrate, in a practical way, the impact that these concepts can have on a project’s success. This case study, which conveys an important message with regard to the application of constructability concepts, was purposely chosen from among prestigious projects in peninsular Malaysia. The basic message, as viewed by the interviewees, is that applying these constructability concepts will enhance a project’s constructability, consequently optimizing the schedule, cost, and quality of the project for the benefit of all the parties involved. The interviewees for the case study agreed that the applied constructability concepts were derived from their own experience and not based on any existing formal program. The absence of a systematic technique for transferring construction experience and knowledge to all the participants in all phases of a construction project is the reason behind the lack of constructability in our construction industry today.     

Automated Rebar Constructability Diagnosis

In spite of impressive progress in project modeling and computer-integrated construction, there is little real integration—manual or computerized—between design and construction of building projects. Consequently, constructability problems are experienced during the construction phase. With regard to rebar, constructability problems are discovered either after casting the reinforced concrete element or not at all, resulting in a weaker element. This paper describes a rebar constructability model, which was developed in an object-oriented graphic environment. The model is intended to be used during the design phase to automatically diagnose potential rebar-related constructability problems (the Diagnosis Module), as well as to offer solutions and implement them (the Correction Module). Of these two modules, the Diagnosis Module was implemented in a concept-proving prototype. The proposed model searches for constructability problems through all relevant parts of the building. This search includes the structural design, as well as other building systems (e.g., sanitary, drainage, HVAC). The model also checks for potential collisions between reinforcement bars and temporary inserts (e.g., form ties). Thus, in addition to the resulting increased constructability, the model also has potential as a system coordination tool.     

Constructability Analysis in the Design Firm

The timely execution of a construction project is very important to the owner, who makes plans and commitments on the basis of the project’s anticipated completion date. Failure of design professionals to consider how a builder will implement the design can result in scheduling problems, delays, and disputes during the construction process. Constructability of design is a subjective scale that depends basically on a number of interdependent project-related factors. Many design firms have a formal (explicit) constructability program that is launched as early as the conceptual planning stage of the project. This research examines design professionals’ efforts to pursue constructability and provides recommendations for performing constructability reviews in an efficient and effective manner.     

Organizing Constructability Knowledge for Design

Construction contractors have significant constructability expertise to contribute to the design process of projects. To utilize this expertise most effectively, the right information must be made available to the design team at the proper point in time and at the appropriate level of detail. Current methods for utilizing construction knowledge in design have made significant advances to improving projects. However, they are typically rudimentary: unstructured, not very efficient, and rely heavily on reviews. Organizing constructability information according to its use in the design process will allow project teams to take the best advantage of the construction expertise. This paper introduces a model for organizing constructability information based on timing and levels of detail. The model differs from current approaches because of this focus. How the model was developed is described. It is tested on six case study projects to assess applicability on different projects. An illustrative example is provided using a detailed case study of the Pentagon renovation project to show how the model can be used as a metric to guide constructability input during design.     

Assessment of Constructability Practices among General Contractors

Modern construction has been characterized as a complex and fragmented process. These characteristics have produced a decrease in the quality and cost efficiency of projects. It has been proven that this problem can be partially overcome by implementing constructability, which is based on the integration of construction knowledge into design (as was done in the past). The implementation of constructability is not easy because it represents a change in the way things have been done in the last century. Prior research has found a lack of constructability efforts among participants in the construction industry, especially general contractors. Because builders can play an important role in implementing constructability, this paper assesses constructability practices among general contractors. The data were obtained from a mailed survey. It was found that contractors applied constructability concepts and participated during the earliest phase of the projects more often than is thought. In addition, the findings showed that constructability practices differed depending on the characteristics of the organization, the type of work performed, and the type of contractual arrangement.     

Impacts of Constructability Improvement

An analysis of the construction resource utilization tradeoffs, which occur from constructability improvements, provides insight into the constructability improvement process. Matrices of construction and engineering impacts likely to result from constructability improvements are presented. Constructability improvements collected on a large industrial construction project are analyzed for their impact to the job. Frequencies of occurrence of both desirable and undesirable impacts are noted, as are the cost‐significances of the various impact types. Constructability strategies and methods for achieving the most cost‐beneficial impacts are presented. Numerous findings are presented, such as the following: (1) The likelihood of delays may be decreased most effectively by increasing engineering information availability and understandability; (2) the amount of required construction manpower may be most effectively decreased by simplifying the design, combining design elements, and seeking optimal design‐originated construction techniques such as optimal construction systems, modularization, and improved design details. Of course, additional engineering effort may be required; and (3) construction activity durations may also be most effectively decreased by seeking optimal design‐originated construction techniques.     

PDM++: Planning Framework from a Construction Requirements Perspective

Construction requirements represent the key preconditions for construction. These include topological precedence, key resources, space requirements, etc. Consequently, identifying them is necessary for feasible construction planning to be achieved. Despite this, little attention has been given to the impact of construction requirements on a project schedule, possibly because of the lack of a good tool for representing these requirements. This paper distinguishes construction requirements into static and dynamic types, according to changes in the need of the requirement during its life cycle. A modeling framework, PDM++, is then proposed. The framework deals with schedule constraints arising from both static and dynamic construction requirements, provides greater semantic expression to capture schedule constraints unambiguously, and facilitates the representation of interdependent conditional relationships. The concept of meta-intervals is also devised to represent complex requirements involving several activities and schedule constraints, and it facilitates modeling at higher levels of plan abstractions. Finally, an illustrative case study is presented to show the applicability of PDM++ in representing schedule constraints and alternative scheduling from a construction requirements perspective.     

Calculating Roller Requirements for Chip Seal Projects

This paper details a mathematical algorithm to determine the required number of rollers for a chip seal project’s equipment spread based on maximizing the asphalt distributor’s production and adhering to specified roller time requirements. The paper reports one of the findings of a three-year constructability review of the Texas Department of Transportation’s statewide seal coat program. One of the findings of that study was that there was a correlation between the number of rollers used on a job and the loss of aggregate after construction was completed. The roller is the tool used to seat the aggregate and create embedment in the asphaltic binder. Thus, the failure to achieve design embedment depth is primarily a function of achieving quality control requirements for roller linger time. The paper illustrates a straightforward method to calculate the required number rollers to achieve both maximum productivity for the chip seal paving train and to ensure a uniform distribution of roller coverage across the width of the shot. The paper concludes that designing the roller spread is in the best interests of both the chip seal contractor and the owner.     

Construction, Inspection, and Maintenance of FRP Deck Panels

Composite materials are clearly having a major impact on how facilities are designed, constructed, and maintained. In order to enhance the application of fiber-reinforced composites in infrastructure renewal, it will be important to understand the constructability, maintainability, operability, and inspection issues related to the use of fiber-reinforced polymer (FRP) structural components. This paper identifies these issues as well as fabrication issues, construction methods, quality, man-hour requirements, cost and productivity issues, and the skill level required to install FRP bridge deck panels. The data required for this research were collected through two questionnaire studies, personal interviews with two manufacturers of FRP bridge deck panels (i.e., Hardcore Composites and Martin Marietta Composites), and candidate projects for FRP bridge deck construction.