Modelling the dynamics of design error induced rework in construction: comment

The bridging of different research disciplines such as computer modelling and design practice requires full understanding of both. Privileging one area of investigation while simplifying the other is not a feasible option. This approach is likely to produce work that scarcely reflects the actual complexity of the phenomena discussed.     

Determining the causal structure of rework influences in construction

One of the most perplexing issues facing organizations in the construction industry is their inability to become quality focused. As a result sub-standard products and services often emanate, which inadvertently result in rework. Typically, rework is caused by errors made during the design process. These errors appear downstream in the procurement process and therefore have a negative impact on a project's performance. The lack of attention to quality, especially during the design process, has meant that rework has become an inevitable feature of the procurement process, and the costs have been found to be as high as 12.4% of total project costs. Such costs could be even higher because they do not represent schedule delays, litigation costs and other intangible costs of poor quality. To reduce the cost and effect of rework, an understanding of its causal structure is needed so that effective prevention strategies can be identified and the effects of rework reduced or eliminated. A case study approach based upon deductive and inductive reasoning is used to identify the major factors that influence rework in projects. From the findings and with reference to recent literature, the concept of system dynamics is used to develop a series of influence diagrams, which are then integrated to develop a conceptual causal loop model that is used to determine the overall causal structure of rework. Once an understanding of the causal structure of rework events has been acquired, effective strategies for rework prevention can be designed and implemented in order to improve project performance. This paper contributes to study of quality in construction by capturing the complexity and dynamism of those factors that influence rework and project performance in a holistic manner.     

Quantifying the causes and costs of rework in construction

Very few construction companies and consulting firms in Australia measure their costs of quality. Consequently, it is difficult for them to prove that systems for preventing quality failures are cost-effective. Although the direct costs of a quality system can be quantified with some accuracy (salaries, costs of documentation, audits, etc.), the corresponding benefits are far more difficult to assess. Indeed quality failures have become an endemic feature of the procurement process in construction and invariably lead to time and cost overruns in projects. Thus, in order to improve the performance of projects it is necessary to identify the causes and costs rework. The research presented in this paper quantifies the causes, magnitude and costs of rework experienced in two construction projects that were procured using different contractual arrangements. The causes and costs of rework projects are analysed and discussed. The findings reveal that the cost of rework for the case study projects was 3.15% and 2.40% of their project contract value. Changes initiated by the client and end-user together with errors and omissions in contract documentation were found to be the primary causes of rework. It is recommended that construction companies and consultant firms (particularly design consultants) implement quality management practices as well as place emphasis on coordinating project documentation during the design development process so that the amount of rework in projects can be reduced or even eliminated.     

Making sense of rework and its unintended consequence in projects: The emergence of uncomfortable knowledge

To make sense of the rework phenomena that plagues construction projects a longitudinal exploration and mixed-method approach was undertaken to understand its causal setting and why it remained an on-going issue for organizations contracted to deliver an asset. The research reveals that rework was an zemblanity (i.e., being an unpleasant un-surprise) that resulted in: (1) project managers ignoring established organization-wide procedures and, at their discretion, amend them to suit their own goals while denouncing the importance of recording and learning from non-conformances; (2) a deficiency of organizational controls and routines to contain and reduce rework; and (3) an absence of an organization-project dyad that supported and promoted an environment of psychological safety. A new theoretical conceptualization of error causation that is intricately linked to rework and safety incidents is presented. The research provides managers with “uncomfortable knowledge’, which is needed to provide insights into the determinants of rework that form part of their everyday practice.     

Investigating the client-related rework in building projects: The case of Singapore

Rework has become one of the most common concerns in construction projects. This study aims to investigate the client-related rework (CRR) in Singapore-based building projects. To achieve the objectives, a literature review and questionnaire survey was conducted and data were collected from 381 projects performed by 51 companies. The results confirmed that the client contributed most to rework. 41 of the 51 companies (80.4%) experienced CRR, and 226 of the 381 projects (59.3%) experienced CRR, which increased project cost by 7.1% and caused 3.3 weeks' delay on the average. Additionally, “replacement of materials by the client” was the cause with the highest frequency of occurrence, while “change of plans or scope by the client” contributed most to CRR and exerted most impact on project cost, schedule and quality performance. This study expands the literature and provides an in-depth understanding of the CRR in Singapore for both practitioners and researchers.     

Perspectives on component-based design in Japanese construction

The industrialization of building production was the subject of heated debate in Japan during the 1960s and into the 1970s. Various concepts of ‘component-based design’ were introduced with the purpose of stimulating innovation and creating a more efficient building process. In this paper these concepts are reviewed from today's perspectives, and the necessary revisions are examined that might make them more useful in contributing to the future development of the Japanese construction industry.     

浅谈设计阶段造价控制的几个要点

本文分析了设计阶段造价控制的重要性,阐述了在设计阶段造价控制的主要方法和应用,以及招投标、监理制度等对造价控制的作用。     

浅谈医院适应性设计

对于生物,适应性是其生存能力的评价标准;对于建筑,适应性同样是影响其生命周期的决定性因素。医院建筑作为一种功能复杂、能耗高且需要时刻不停运转的公共建筑,其发展需要通过新陈代谢般的更新来完成,因此,适应性对其有着特殊的意义。     

浅谈质量管理体系在建筑给排水设计中的应用

建筑给排水设计中,工作岗位任务划分,设计过程中的质量、进度管理,设计成本控制、设计文件的记录及归档,绩效考核及工作总结管理构成了质量管理体系框架,应用质量管理体系可以保证设计质量,提高工作效率,降低设计成本。     

Determining the probability distribution of rework costs in construction and engineering projects

Rework arises due to design errors, changes and omissions during design and has been found to contribute to 52% of a project's cost overrun. The statistical characteristics of rework costs experienced from contract award in 276 construction and engineering projects were analysed. The skewness and kurtosis values of rework costs are computed to determine if the empirical distribution of the data follows a normal distribution. The empirical distributions for rework costs are found to be non-Gaussian. Theoretical probability distributions are fitted to the rework data. The Kolmogorov–Smirnov and Anderson–Darling non-parametric tests are used to determine the ‘Goodness of Fit’ of the selected probability distributions. A Generalised Pareto probability function is found to provide the best overall distribution fit for rework costs. The Generalised Pareto distribution is used to calculate the probability of rework being experienced for the selected sample. Projects with a contract value <A$1million had higher rework probabilities than that of >A$101 million. Larger projects may be better managed and longer completion times provide an opportunity to make adjustments to facilitate cost control. The anticipation that rework will occur using the probabilities that are derived can enable a quantitative risk assessment to be undertaken prior to the commencement of construction.     

Landscape Dynamics and the Management of Change

Change in economy and society is directly reflected in the character of landscapes, both in terms of their form and function and the landscape planning and management challenges which they present. The phenomenon of landscape dynamics within post-industrial society is considered and the development of a connection between the drivers of landscape change and the management response is sought. Two key drivers of landscape change are proposed - 'obsolescence' and 'dysfunction' - and these in turn are related to a management matrix bounded by axes of condition and character of landscape. It is suggested that the definition of these relationships helps to substantiate and more clearly define the tasks of landscape planning, design and management in the United Kingdom.     

建筑的传统性与时代性——乡土建筑设计教学的探索

在乡土建筑设计教学过程中对建筑设计与建筑教育加以反思,从设计的角度探索建筑的传统性与时代性的关系,寻求将传统性与时代性结合的契机;同时又从教育的角度对课题设置、教学程序、设计方法等进行研讨,尝试如何将建筑史学与建筑理论直接、具体地运用于指导建筑设计。提倡历史、理论、设计三位一体教学观念,并力图创立一种综合的、开放的建筑设计思维方法。     

Considerations and strategies behind the design and construction requirements of the Istanbul Strait immersed tunnel

This being a design-build project, the challenge faced during preparations of the Employer’s requirements for design and construction of the Istanbul Strait immersed tunnel was to give the contractor as much freedom as possible and yet specify enough so that the Employer obtained the required facility. When completed, this will be a world-class facility. This paper discusses on a strategic level many of the aspects to be presented by the author in two papers in later sessions of the day. Unusual features of this crossing include the deepest ever immersed tunnel crossing, extra waterproofing requirements, strong currents with bi-directional flow, close proximity of the North Anatolian Fault which is predicted to have a major seismic event during the life of the tunnel, and the method of connecting the adjacent bored tunnels to the immersed tunnel. Safety during tunnel construction and operation has been paramount, and resulted in changes to contract packaging and extra requirements. Other challenges discussed include fish migration, control of an international waterway, environmental issues and ensuring the stability of the soft soils during a seismic event.     

Application of information technologies in building design decisions

Research and development of a new sophisticated software environment to support building design decisions are presented. This new software, the Building Design Advisor (BDA), is intended as a research tool, teaching aid and, eventually, as a practical professional tool to facilitate both strategic and detailed decision-making throughout the design process from the early schematic phases of building design through to the detailed specification of building components and systems. BDA supports the integrated, concurrent use of multiple simulation tools and databases, while allowing output to support multicriterion judgement. BDA's ultimate aims are to address the data needs of whole building life cycle analysis: design, construction, commissioning, operation, performance and demolition. Cette communication presente les travaux de recherche et de developpement portant sur un nouvel environnement logiciel sophistique destine a faciliter la prise de decisions en matiere de concepts de construction. Ce nouveau ligiciel, denomme Building Design Advisor (BDA), est a la fois un outil de recherche, une aide pedagogique et, finalement, un outil professionnel pratique qui facilite le processus decisionnel strategique et detaille tout au long de la procedure de conception, des la premiere phase d'esquisse de conception d'un batiment jusqu'a la specification detaillee des composants et des systemes de ce batiment. Le BDA est compatible avec l'utilisation integree et simultanee de multiples outils de simulation et de bases de donnees et ses resultats sont compatibles avec des jugements multi-criteres. Les objectifs ultimes du BDA sont d'etudier les besoins en donnees du processus d'analyse du cycle de vie complet d'un batiment: conception, construction, mise en service, exploitation/performances et demolition.     

Human error in the management of building projects

This paper seeks to improve the understanding of human error as it is applied to the generation of defects in construction projects. It reviews the literature concerning human error, commencing at the psychological basis of errors. From this, the review is expanded to include literature from forensic engineering, industrial safety, reliability engineering, sociology and quality management. Based on the literature, a model of the factors influencing the incidence of errors in project based industries is constructed. This model proposes that errors leading to defects and more dramatic failures can be generated from all levels of project organizations. They stem from primary factors (related to the performance of the individual), management factors (related to a range of managerial tasks) and global factors (related to wider external influences). These factors can be displayed as a hierarchy with primary factors at the base and global factors at the top. The paper reports on the results of an initial test of this model by reference to a survey of a sample of construction industry practitioners. The findings of the survey support the model, with some modifications. Additionally, some differences in view were noted: in particular, respondents from a construction background emphasized managerial factors more strongly than those from a design background.     

浅析酒店智能化系统建设

笔者在文中着重分析了酒店智能化系统建设中存在的一些问题,并就如何做好酒店智能化系统的后期维护保障服务提出了自己的建议。     

Use of system dynamics as a decision-making tool in building design and operation

This paper presents a decision-making tool based on the system dynamics method for building design and operation, and demonstrates the use of the method for the analysis of a building subjected to a bioterrorist attack. A literature review of prior uses of the system dynamics method, focusing mainly on historic uses within civil and environmental engineering and related disciplines is first presented, to make the case for the applicability of the system dynamics method as a decision-making tool for building system design, retrofit, and operation. A proof-of-concept system dynamics model is presented for modeling of an elementary building system subjected to a bioterrorist attack. The proof-of-concept model includes evaluation of modifications to the building and its defenses. The results of the model simulation are presented and compared with previously published data. Use of the output data to improve decision-making in building design, retrofit, and operation is discussed. A method to link an electronic building information model (BIM) of the building to enable the electronic capture of the relevant building features in the system dynamics model is also discussed and demonstrated. Finally, future development of the model and other potential areas of applicability for the modeling methodology are discussed.     

计算机辅助设备的优化配置及相关硬件问题的解决

计算机配置即计算机主机与打印机、绘图仪等辅助设备数量上的对应比例,这个比例如果合理,可以节约大量的资金,提高设备利用率,本文总结数年工作经验,不但提出了优化的配置方案,而且提供了在实现这些方案时所遇到硬件问题的解决方法。     

网络型访客管理系统在安保管理工作中的应用

本文通过分析安保管理工作对访客管理的需求,介绍了网络型访客管理系统的组成、功能及应用。文章还分析了网络型访客管理系统对网络资源的占用情况,并与传统登记簿管理方式进行了比较。