For many years, the walkie-talkie has been synonymous with the construction industry. During jobsite project execution, there are three variables which can either hinder or facilitate successful results, namely, quality, quantity, and timing of information. Wireless data communications technology is capable of delivering just-in-time information within the 'last mile' between the trailer and a desired location on the jobsite. This paper reports on a study which surveyed information needs at the jobsite, emerging wireless data communications technology, and assessed the extent to which wireless data technology can fulfill the information needs of the jobsite [J.M. de la Garza, I. Howitt, Wireless communication and computing at the jobsite, Research Report 136-11, Construction Industry Institute, Austin, TX, 1997]. We have organized jobsite information needs into the following ten categories: (a) requests for information, (b) materials management, (c) equipment management, (d) cost management, (e) schedule and means and methods, (f) jobsite record keeping, (g) submittals, (h) safety, (i) QC/QA, and (k) future trends. Each category was analyzed in terms of its appropriateness to take advantage of wireless technology. The four formats considered to transmit information wirelessly were: (a) live voice, (b) live video, (c) batched data, and (d) live data. Current wireless communication technology has been classified into the following five classes: (a) circuit-switched wireless data systems, (b) packet-switched wireless data systems - this class was further subdivided into specialized mobile radio systems and cellular digital packet data systems, (c) wireless local area networks, (d) paging systems, and (e) satellite-based data communications. A primer for wireless communications covering both fundamental and advanced communications concepts has also been included to enable a better understanding of the issues involved in making trade-offs while configuring a wireless jobsite communication system. The example presented in this paper shows how a contractor can define a subset of information needs by choosing from those already articulated herein and determine if a given wireless technology should even be considered as a viable way of meeting the information needs that such company has.
This paper reports on findings of a November 1996 exploratory survey of architecture-engineering clients (Fortune 500 corporate facility managers). This research investigated how the practices of corporate facility managers are being influenced by rapid changes in information technology. The conceptual model that served as a guide for this research hypothesized that information technology acts as both an enabler (that is, information technology provides an effective mechanism for managers to implement desired changes), as well as a source of innovation (that is, new information technology innovations create new facility management opportunities). The underlying assumption of this research is that information technology is evolving from a tool that incrementally improves 'back-office' productivity to an essential component of strategic positioning that may alter the basic economics, organizational structure and operational practices of facility management organizations and their interactions with service providers (architects, engineers, and constructors). The paper concludes with a discussion of researchable issues.
The rapidly developing area of construction automation leads construction managers to critically evaluate the feasibility of replacing conventional construction processes by automated systems. This decision requires careful analysis of tangible and intangible factors such as need-based criteria, economic criteria, technological criteria, project specific criteria, and safety/risk criteria. This paper presents a decision making model and a decision support system (DSS) to assist construction managers in systematically evaluating whether to opt for a conventional construction process or an automated system for a given project. The proposed DSS, called AUTOCOP (AUTomation Option evaluation for COnstruction Processes), utilizes the Analytical Hierarchy Method (AHP) to analyze the tangible and the intangible set of criteria involved in the decision problem.
The work reported in this paper addresses the paradoxical state of the construction industry (also known as A/E/C, for Architecture, Engineering and Construction), where the design of highly integrated facilities is undertaken by severely fragmented teams, leading to diminished performance of both processes and products. The construction industry has been trying to overcome this problem by partitioning the design process hierarchically or temporally. While these methods are procedurally efficient, their piecemeal nature diminishes the overall performance of the project. Computational methods intended to facilitate collaboration in the construction industry have, so far, focused primarily on improving the flow of information among the participants. They have largely met their stated objective of improved communication, but have done little to improve joint decision-making, and therefore have not significantly improved the quality of the design project itself. We suggest that the main impediment to effective collaboration and joint decision-making in the A/E/C industry is the divergence of disciplinary 'world-views', which are the product of educational and professional processes through which the individuals participating in the design process have been socialized into their respective disciplines. To maximize the performance of the overall project, these different world-views must be reconciled, possibly at the expense of individual goals. Such reconciliation can only be accomplished if the participants find the attainment of the overall goals of the project more compelling than their individual disciplinary goals. This will happen when the participants have become cognizant and appreciative of world-views other than their own, including the objectives and concerns of other participants. To achieve this state of knowledge, we propose to avail to the participants of the design team highly specific, contextualized information, reflecting each participant's valuation of the proposed design actions. P3 is a semantically-rich computational environment, which is intended to fulfill this mission. It consists of: (1) a shared representation of the evolving design project, connected (through the World Wide Web) to (2) individual experts and their discipline-specific knowledge repositories; and (3) a computational project manager makes the individual valuations visible to all the participants, and helps them deliberate and negotiate their respective positions for the purpose of improving the overall performance of the project. The paper discusses the theories on which the three components are founded, their function, and the principles of their implementation.
Asphalt pavement density from roller compaction is a crucial factor in ensuring satisfactory pavement performance. Proper and uniform compaction of the pavement mat is essential in achieving the desired final compacted density. There is a necessity to investigate existing pavement construction practices, and provide more cost-effective modifications to the current scenario. Automation of the paving operation can increase the efficiency and quality of the operation, lead to reductions in overall project costs and time, and enhance pavement life. A system can be developed through algorithmic planning and real-time guidance strategies, and the development of a semi-automated path-planning and real-time guidance system that aims towards automating the paving operation. This system accepts relevant paving project inputs, generates appropriate path plans for the compactor, performs a graphical visualization of the generated path plan, and offers real-time guidance capabilities using Global Positioning Systems (GPS) technology. This system, named AUTOPAVE (v1.0), was developed in Microsoft Visual Basic™ programming language and offers a user-friendly and interactive graphical interface. The proposed new system will incorporate state-of-the-art GPS technology to standardize paving operations that are more amenable to rigorous quality control, and can result in considerable reductions in cost and time involved in asphalt pavement construction projects. This system was tested on several actual paving projects, and many operational issues related to the functioning of the system were successfully overcome.
Case-based reasoning (CBR) approach recalls and learns from previous cases to resolve or provide recommendations for current problems. This study presents a case-based retaining wall selection system (CASTLES) in which the case base consists of 254 previous retaining wall cases in design reports in Taiwan. According to the ability of the user's input to accurately describe the characteristics of a new project and a predefined similarity function, CASTLES identifies a set of feasible retaining-wall systems from the case base. Comparing CASTLES with four actual field cases reveals that the case-based reasoning approach is highly promising for selecting retaining wall systems.
Tower cranes enjoy a long useful working life. Therefore, a vast population of cranes are still in use today that do not feature the advanced automation and sensor technologies such as those with which some of the new models are equipped. This paper examines the technological and economic feasibility of retrofitting existing tower cranes with semi-automatic devices for motion control. The proposed improvements are intended to enhance the cranes' efficiency and their capacity to meet the challenges of today's tightly scheduled construction projects. Based on work studies and analyses of craning cycles, the concept offered by the proposed improvements distinguishes between the long-distance navigation of the crane's hook and the fine maneuvering in the loading and unloading zones. The expected economic benefits resulting from the enhancement of the crane's performance, with regard to both types of motion, far exceed the cost of installing the various devices.
Successful project management requires the effective control of the design teams and the exchange of information between them for successful design management. This paper describes a methodology involving discrete event simulation that can help the planning and control of building design. Discipline-based information flow models of the building design process are used to define the activities of the simulation model, concentrating on the concept and schematic design stages. Factors such as task durations and resources are then allocated along with any specific constraints that are to be evaluated. The model predicts the outcomes of the specific scenario of information related events, including design schedules and resource histograms. The paper describes the development and validation of the simulation model and discusses its potential application during the planning and design phases of building projects. It is concluded that this approach could form the basis of a useful tool for design managers responsible for multidisciplinary building design work.
This paper examines psychological evidence on the nature and role of representations in cognition. Both internal (mental) and external (physical or digital) representations are considered. It is discovered that both types of representation are deeply linked to thought processes. They are linked to learning, the ability to use existing knowledge, and problem solving strategies. The links between representations, thought processes, and behavior are so deep that even eye movements are partly governed by representations. Choice of representations can affect limited cognitive resources like attention and short-term memory by forcing a person to try to utilize poorly organized information or perform 'translations' from one representation to another. The implications of this evidence are discussed. Based on these findings, a set of guidelines are presented, for digital representations which minimize drain of cognitive resources. These guidelines describe what sorts of characteristics and behaviors a representation should exhibit, and what sorts of information it should contain in order to accommodate and facilitate design. Current attempts to implement such representations are discussed.
Discrete event simulation modeling has been used successfully in a wide range of industrial and manufacturing applications. In construction applications, even though simulation has been applied, it still is extremely limited in terms of wide deployment in construction projects. Several reasons limit the effective implementation of this technology in construction. Chief among them is the time needed to develop the simulation model. While developing models for industrial applications is just as time consuming, the perpetual nature of manufacturing activities, may make this investment worthwhile. However, this is not the case in construction. In this research, the authors approach the problem through the development of a library of preprogrammed construction resources. The user need only select the required resources, and specify the project logic by linking these resources together. Benefits of this approach are the increased communication between the members of the construction team. Also the potential application of simulation tools in unforeseen construction situations where the time associated with hiring a simulation programmer may not available and a quick response is required.
At the core of any computational system that can support design development, analysis, and evaluation is an 'intelligent' building representation which should be able to represent all the different components that make up a building, along with the manner in which they come together. In other words, the representation must be informationally complete and semantically rich. The paper discusses these two criteria and briefly reviews other research efforts aimed at developing building representations for computer-aided design that attempt to meet them. Our solution to this problem is then presented. It is aimed primarily at the schematic design phase, the rationale for which is also stated. Taking the view that buildings are unique assemblies of discrete, mostly standardized components, our representation is clearly divided into two components: the Object Database (ODB) which stores detailed information about various building elements, and the Project Database (PDB) which holds information about how these elements are assembled to make up a particular building. An ODB may be shared by many building projects, while the PDB must necessarily be unique to each. The data schemas of both the PDB and the ODB are described in detail and their computational implementation, to the extent that it has been completed, is illustrated.