To perform rational defect prevention, it is necessary to have knowledge about defects, their causes and associated costs. The purpose of the study presented here is to stimulate improvements by indicating where preventive measures are most effective as well as how to perform them. A study of defects in construction was performed during the period 1986-1990. A new and deeper study has been performed by the same research group during 1994-1996. Seven building projects have each been monitored during a 6 month-period. Observers spent 8 h a day at the site analysing and describing defects occurring. A total of 2879 defects have been collected and fully described, including their root causes. Formal interviews with 92 key persons have been made.
Facility designers can positively influence construction site safety by integrating safety considerations into the design process. Although their potential influence on safety has been documented, designers typically lack knowledge of and limit their involvement in construction worker safety. This research effort involved the accumulation of suggestions for improving construction worker safety while in the design phase. Using these design suggestions, a design tool has been developed to assist designers in identifying project-specific safety hazards and to provide best practices to eliminate the hazards. Although use of the design tool is voluntary in the United States, it is one resource which can be used by designers to fulfill their obligations required by the Construction (Design and Management) Regulations in UK.
The initiation of a renovation project usually involves a long process of contemplation under conditions of high uncertainty. Large organizations, that own many buildings and other facilities, can greatly benefit from a decision-support model, which can be transformed to a computerized semi-automatic tool. It will aid them develop and execute a reasonable and economical policy of rehabilitating, renovating, remodeling, or rebuilding their facilities. This paper presents a systematic four-module decision support model: (a) Preliminary survey of background conditions; (b) Evaluation and ranking of the facility's physical condition; (c) Generation of viable alternatives for rehabilitation, renovation, or reconstruction; and (d) Quantitative techno-economic comparison among the alternatives, and systematic presentation of recommendations. The paper concludes with a demonstrative example, concerning the renovation of a 25-year-old dining facility, that highlights both the practicality of the model and the benefits from utilizing it.
For the past ten years most sectors of industry have been developing standards for the electronic sharing and exchange of product model data. While several related industries, such as automotive and shipbuilding manufacturing have been relatively successful in integrating electronic product models into their operations, the building and construction industry, continues to lag behind in this development. In order for the building and construction industry to meet the challenges of the future, the development of a product modeling standard that enables sharing, storing and exchanging project information electronically is essential. The paper discusses the rationale behind this assertion and includes a discussion of the industry requirements for the development of a product modeling standard. The paper elaborates on the results of the standardization efforts of the past and present, followed by an analysis of the current development situation. Finally, personal views are expressed regarding future development in the area of information exchange.
Post-occupancy evaluation (POE) has been developed to address the problem of acquiring feedback from the occupants who are, arguably, in the best position to provide information for a future design database. This paper presents a study of the factors (on both physical and social levels), which influence residential satisfaction of a sample of occupants in a chosen residential area in Hong Kong; factor analysis and multiple regression were carried out on the data. A comparison is also made of the perceived factors of dissatisfaction amongst the public and private housing occupants. It is suggested that a wider systematic coverage of the subject through investigative and diagnostic POE should be carried out in Hong Kong.
Even before Louis Sullivan coined the phrase `Form Follows Function,' architectural researchers have sought, to no avail, a causal relationship between these two primary constituents of the building enterprise. This paper attempts to explain why this quest has been futile, and proposes a performance-based design paradigm, instead of the prevailing process-based paradigms. It suggests that the driving force behind any design activity is the desire to achieve a qualitative solution for a particular combination of form and function in a specific context. Furthermore, it suggests that quality can only be determined by a multi-criteria, multi-disciplinary performance evaluation, which comprises a weighted sum of several satisfaction/behavior functions. The paper develops a performance-based design methodology and demonstrates its application in an experimental, knowledge-based CAD system.
This paper presents a multi-criterion decision model for quantitative constructability analysis based on a neuro-fuzzy knowledge-based system. The traditional constructability definition is modified so that constructability can be quantified, measured, and improved. A multi-layer information aggregation network is proposed to incorporate the manager's subjective preference information. The constructor's technology management policy can be reflected in the constructability evaluation process based on technology implementation preferences. A systematic approach to constructability problem detection and constructability improvement is developed to improve technology performance. Two examples of constructability analyses for alternative concrete formwork technologies are given to demonstrate the functions of the proposed methodology.
This paper presents an approach to the integration of site-related activities into the planning and scheduling of the entire construction project. The paper starts by briefly reviewing some common methods used by construction firms in the planning and scheduling of site activities. Next follows a discussion of current research efforts concerned with the modelling of site-related procedures. Then a virtual-reality-based model is proposed, which uses both knowledge-based simulation of the work progress and visualisation capabilities, to achieve the desired integration. Finally the prototype system is described and its potential is demonstrated through several examples.
In many countries around the world, building codes are shifting from prescriptive- to performance-based for technical, economic, and social reasons. This move is made possible by progress in fire safety technologies, including the development of engineering tools that are required to implement performance codes. The development of performance-based codes follows a transparent, hierarchical structure in which there are usually three levels of objectives. The top level objectives usually state the functional requirements and the lowest level the performance criteria. Usually, one middle level exists, however, more levels can be used in this hierarchical structure depending on the complexity of the requirements. The success of performance-based codes depends on the ability to establish performance criteria that will be verifiable and enforceable. The performance criteria should be such that designers can easily demonstrate, using engineering tools, that their designs meet them and that the code authority can enforce them. This paper presents the performance criteria that are currently used by fire protection engineers in designing fire safety systems in buildings. These include deterministic and probabilistic design criteria as well as safety factors. The deterministic criteria relate mainly to life safety levels, fire growth and spread levels, fire exposure and structural performance. The probabilistic criteria focus on the incident severity and incident likelihood. Finally, the inclusion of safety factors permits a conservative design and allows for a smaller margin of error due to uncertainty in the models and the input data.
This paper describes a methodology for constructability knowledge acquisition of construction technologies. The methodology combines a neuro-fuzzy network-based approach with genetic algorithms. The combination of fuzzy logic with learning abilities of neural networks and genetic algorithms may allow for automatic acquisition of constructability knowledge from training examples and for providing understandable explanations for the reasoning process. The proposed methodology can provide a mechanism to trace back factors causing unsatisfactory construction performance and the necessary feedback to construction engineers for technology innovation. An application example is provided to demonstrate the capabilities of the proposed methodology.
This paper focuses on information modeling and computing technologies that are most relevant to the emerging software for the Architecture, Engineering, and Construction (AEC) industry. After a brief introduction to the AEC industry and its present state of computer-based information sharing and collaboration, a set of requirements for AEC information models are identified. Next, a number of key information modeling and standards initiatives for the AEC domain are briefly discussed followed by a review of the emerging object and Internet technologies. The paper will then present our perspective on the challenges and potential directions for using object-based information models in a new generation of AEC software systems intended to offer component-based open architecture for distributed collaboration.
This paper identifies briefing as a persistent problem area for the construction industry and suggests that little development has occurred in briefing practice in 30 years. A research project is then described which aims to address the problem and lead to real improvements in briefing. Using techniques derived from grounded theory, initial results indicate that the issue is not simply a matter of good practice not being implemented-it is deeper than this, often involving the human dimension. This leads to an analysis of the problem in terms of human error theory and a discussion of the limits of the application of a rationalistic approach to briefing. Conclusions are drawn, pointing towards the need for new, richer perspectives to be taken if improvements in briefing are to be achieved in practice, or indeed in theory.
This paper introduces a comprehensive computational implementation effort toward the incorporation of simulation-based performance evaluation in building design. Specifically, the computational design support system `SEMPER' will be described. SEMPER's main objectives are: (i) a methodologically consistent (first-principles-based) and flexible performance modeling approach through the entire building design and engineering process; (ii) provision of comprehensive, i.e., multi-domain building performance evaluation support; (iii) seamless and dynamic communication between the simulation model and the general building representation in an object-oriented space-based design environment; and (iv) active convergence support via a bi-directional inference mechanism that provides not only the conventional design-to-performance mapping option but also a `preference-based' performance-to-design mapping technology.
Global population and environmental trends demand a radical departure from current building and developmental processes. Applying total building performance thinking can reduce energy consumption, pollution and waste in existing and new construction by a factor of 4 and simultaneously can improve quality of life within buildings - measured through occupant satisfaction, health and productivity. The further development of advanced energy and water systems, and the application of appropriate technology and systems integration concepts will help to enable the elimination of `waste-streams', avoiding obsolescence, as well as managing industrial and agricultural nutrient streams. Instead of treating buildings and their contents as `pre-garbage', worse `pre toxic-waste', all material flows can be considered within life cycles for `cradle to cradle' use. These concepts can make major contributions towards the creation of more sustainable lifestyles with even greater quality in the industrialized countries and the development and implementation of sustainable urban and building infrastructures in rapidly emerging economies. Rather than the continued export of non-sustainable building solutions, this paper argues for the development and demonstration of such practices in the industrialized countries that would create a progressive `pull' to enable the appropriate implementation of new practices.
This paper presents the facilities in the EDM-2 product modeling and database language that support model evolution. It reviews the need for model evolution as a system and/or language requirement to support product modeling. Four types of model evolution are considered: (1) translation between distinct models, (2) deriving views from a central model, (3) modification of an existing model, and (4) model evolution based on writable views associated with each application. While the facilities described support all for types of evolution, the last type is emphasized. The language based modeling capabilities described in EDM-2 include: (a) mapping facilities for defining derivations and views within a single model or between different models; (b) procedural language capabilities supporting model addition, deletion and modification; (c) support for object instance migration so as to partition the set of class instances into multiple classes; (d) support for managing practical deletion of portions of a model; (e) explicit specification and automatic management of integrity between a building model and various views. The rationale and language features, and in some cases, the implementation strategy for the features, are presented.
This paper presents a research study aimed at developing a method for improving the materials supply system in small-sized building firms using total quality management (TQM) principles. The study involved three companies from the Brazilian building industry, which worked cooperatively through several stages of TQM implementation. The proposed method is based on simple well-known quality techniques for problem identification, analysis and solving, such as flowchart, brainstorming, checklist and Pareto diagram. The paper points out some of the difficulties in applying such techniques and principles in small-sized building firms and discusses some typical problems found in materials supply systems of such companies in Brazil.
Australia has a high ratio of infrastructure to population, much of it constructed in a peak period after the end of the Second World War. This infrastructure is aging and becoming due for renewal. However the growth and easy finance conditions that gave rise to its initial development no longer exist and the costs of renewal need to be found in a more difficult economic climate. There is growing anecdotal evidence that some communities may face difficulty in funding renewal of their inherited infrastructure and there is the possibility that the high ratio of infrastructure to population may, in some cases, be unsustainable. Unfortunately, information to test this proposition does not generally exist. While Australian governments, at all levels, are now adopting accrual accounting practices and recording assets in their balance sheets, the attention to asset recording is of recent vintage. This has resulted in the need for large scale asset data capture exercises and large scale investment in information technology, but these are being carried out by individual agencies with little or no co-ordination regionally or across the whole of government. This paper reports a major exception to this pattern: an information management and data gathering project across the whole of Victoria, which has enabled all 78 councils involved to predict the cost and timing of their future infrastructure renewal liabilities (A$23.3 billion) in time to develop corrective planning strategies. By using independent consultants to gather data from every council in the state through a standard survey instrument and presenting the results of the data, after extensive data validation processes, on an aggregate, grouped and single council basis, councils now have the ability to compare themselves with others and with the general state picture. The future renewal challenge is now seen to be a general one, reflective of the times, rather than of individual past management practice, and as such is being tackled with greater vigor. Other States in Australia are now looking to adopt this renewal projection method. This paper also includes reference to the major strategies that are being adopted.
Several methods of electronic data transfer are available to construction organisations and their clients. These technologies are collectively called Information Exchange (IE). This paper reviews partnering, alliances and Information Exchange. A case study involving a major industrial project constructed under an alliance agreement was used to highlight the important issues relating to these areas of study. This study also provided the focus for a survey of 67 major construction organisations. The findings of this survey confirmed that construction alliance and IE have reciprocating benefits which together produce a significant impact on the project.