A simulation optimisation tool for planning of low-income housing projects

Construction of low-income housing projects is a recurring process and is associated with uncertainties that arise from the unavailability of resources. This paper presents a case study that discusses how computer simulation and optimisation are used to aid government agencies and/or contractors in planning of such projects. It illustrates the optimisation of project objectives, taking into consideration the interaction amongst involved resources. As such, total duration and the associated total costs, including direct and indirect costs, can be estimated and optimised. One Youth Habitation project that is executed in 6th of October City in Egypt is analysed in a step-by-step procedure to demonstrate the capability of proposed computer simulation and optimisation prototype (named LIHouse{_}Sim) in the modelling construction of low-income housing projects using bearing block walls with hollow core technique. The presented tool proves its practicality to contractors in estimating the time and costs of the recurring process of low-income housing construction, considering complex interdependencies between construction resources and the uncertainties associated with construction activities. The LIHouse{_}Sim prototype is used to perform a wide analysis for the alternative of the effective optimisation criteria in the bearing block walls/hollow core technique and for the genetic algorithm optimisation approach elements.     

Embedding occupational health and safety in the procurement and management of infrastructure projects: institutional logics at play in the context of new public management

The research explored the approaches used by government agencies (as client organizations) to drive occupational health and safety (OHS) performance improvements in publicly funded infrastructure construction projects in Australia. Semi-structured interviews were conducted with 32 representatives of clients and contractors with direct and recent experience of delivering large public infrastructure projects. Interviews explored the procurement approaches taken, and the use of incentives and performance measurement. Data was subjected to inductive analysis to identify emergent concepts and themes relating to the way that New Public Management (NPM) influences the commercial management of infrastructure construction projects, with particular reference to OHS impacts. The concept of institutional logics was utilised as a theoretical frame to understand clients’ behaviour in the commercial management of infrastructure projects. Client behaviour was consistent with elements of NPM and reflected a managerialist logic in the pursuit of efficiency, the use of targets, incentives and performance measurement. However, a strong professional service logic was also found to drive active client behaviour in relation to the management of OHS. Understanding the institutional logics driving client OHS practices is an important theoretical development that can stimulate reflexive practice which may create an impetus for change.     

Impact of pre‐construction planning and project characteristics on performance in the US electrical construction industry

The mild recession experienced in the early part of this decade forced many US electrical contractors to reduce their profit margins as a way to win jobs and survive economically. However, to make up for lower profit margins, contractors turned to ‘better planning’ as a method for improving their efficiency and increasing their profitability. In general, contractors believe that better planning contributes to better project performance, but the evidence has been mostly anecdotal. A study was conducted recently that transformed anecdotal evidence about the impact of pre‐construction planning on performance into quantitative evidence. The research resulted in the development of a model pre‐construction planning process that was based on outstanding projects that were well planned and performed well. The study quantified the relationship between pre‐construction planning activities, project characteristics and performance, and a separate validation study found that those projects that performed a comprehensive planning process similar to the model planning process were more likely to achieve their estimated work hours, profit, budget and completion goals.     

Parameter prediction for cash flow forecasting models

The paper describes the application of the DHSS formula to 27 completed construction projects comprising four types - steel-framed low rise buildings, new build housing developments, housing refurbishment projects, and multi-house ‘pre-paint’ maintenance contracts. Application of the formula to individual projects indicates that the ‘best’ parameter values offer a ten-fold improvement over the published values based on project size. Similar results occur when using the best parameter values for other two parameter models.

Various approaches are considered in attempting to predict the best parameter values of the models based on known characteristics of the project. A multiple linear regression with project value, duration, and type independent variables is shown not to produce any significant improvement on standard DHSS formula predictions. However, a reduction in the number of independent variables by cross validation produces an approximately 25% improvement on standard DHSS formula forecasts outside the data base. Examination of the models derived from this analysis indicate the type of project to be of major importance.     

Impact of organization size and project type on BIM adoption in the Chinese construction market

Building Information Modelling (BIM) is perceived as an effective tool for improving the delivery and coordination of construction projects. The Chinese construction sector has demonstrated significant interest in implementing the 3-dimensional modelling-based process. BIM adoption is influenced by several factors which can either be operational or strategic related. Factors which can have a significant impact include the size of the construction organization and the type of projects that the organization has to deliver (i.e. building vs infrastructure projects). This study aims to evaluate the effect of project type and size on BIM adoption in the Chinese market, via an adoption model which analyses factors impacting the adoption decision. The study examines 200 samples collected from the Chinese construction industry, split equally between infrastructure and building construction data groups, as well as SMEs and large organizations. The collected data are first analyzed by principal component analysis and then through a Structural Equation Modelling-based multiple group analysis. Results demonstrate that essential factors such as operational risks are considered by small organization, whereas large organizations focus on implementation challenges. Implementation benefits and challenges are significant on the adoption decision in infrastructure organizations, but not in building organizations. In addition, the study reveals that “technical support” is an important factor when it comes to BIM adoption among all types of organizations, regardless of the organization’s size and project type delivered.     

工程总承包模式及其在煤炭建设项目中的应用分析

在分析国内外相关理论研究和实践成果的基础上,指出工程总承包的根本目的在于确立工程建设的单一责任,在实现途径上依赖于竞争性招标、业主方的施工管理、可建造性技术和快速路径技术,在具体实施中有多种组织结构和实施程序方面的变异类型。最后,结合煤炭建设的具体特点,指出了工程总承包模式在煤炭项目建设上有着其他项目承发包方式不可比拟的优势,探讨了煤炭建设项目使用工程总承包模式所面临的社会认知、法律法规、业主角色和承包商能力的阻碍,并针对这些阻碍提出了相应的解决对策。     

Design-and-build contractors' service quality in public projects in Singapore

In the construction industry, total quality comprises corporate service quality, project service quality and quality of the constructed facility. This study investigates the project service quality of design-and-build (D&B) contractors when undertaking projects for public sector clients in Singapore. Service quality is operationalized into five determinants: reliability, responsiveness, assurance, empathy and tangible. From these, 34 attributes that may affect project service quality in D&B projects are identified. A questionnaire is used to ascertain clients' service quality expectations of these 34 attributes. The clients were also asked the extent to which D&B contractors achieve project service quality. It is found that D&B contractors did not meet clients' expectations in all the five dimensions of service quality. This means that D&B contractors are not giving clients the satisfaction that they hope for. This study offers D&B contractors feedback relating to clients' expectations of their service delivery and the areas of service that need to be improved in order to provide quality service that will satisfy public sector clients.     

The role of multi-firm satisfaction in construction project success

Construction project success depends on the multi-firm project organizations involved working together satisfactorily. Yet, satisfaction within multi-firm relationships has rarely been examined as a determinant of construction project success. A pioneering study is carried out to evaluate the extent to which construction project participants’ perception of each other’s performance reflects on the owner’s perception of project success. The data represent 580 performance evaluations carried out among the project owners, project consultants, main contractors and designers. The owner-evaluated performance factors related to the project goals form a dependent variable called Project Success. Dependencies between Project Success and the various performance factors are identified based on Pearson’s correlation coefficients. Dependencies were discovered between Project Success and all owner-related relationships and all but one of the non-owner-related relationships. Preliminary sets of discipline-specific and evaluator-specific success factors are identified. The results support the proposition that satisfaction within both owner-related and non-owner-related relationships is reflected on success. Therefore, researchers and practitioners are encouraged to consider project success in terms of multi-firm satisfaction and to engage with multi-firm performance measurement to better understand the heterogeneous performance factors contributing to multi-firm project success.     

An alternative classification of project delivery methods used in the United States building construction industry

Although many sources describe the project delivery methods available to owners, there is little empirical data on their defining characteristics. The objective of this research was to examine patterns in contract arrangements, procurement practices and compensation terms used in the US building construction industry. Survey data were collected for projects completed between 2008 and 2013 (N = 204) from owners and contractors belonging to large US professional organizations. A latent class analysis was used to identify five distinct patterns or ‘classes’ based upon eight characteristics of the project delivery process. These classes were defined as: (I) late builder and trade involvement, with an open, cost-based selection and lump sum contract (9% of projects in sample); (II) late builder and trade involvement, with a prequalified, cost-based selection and lump sum contract (19%); (III) early builder and late trade involvement, with a prequalified non-cost based selection and guaranteed maximum price (GMP) contract (26%); (IV) early builder and trade involvement, with a prequalified, cost-based selection and lump sum design-build (DB) contract (27%); (V) early builder and trade involvement, with a prequalified, non-cost based selection and GMP DB contract (18%). Compared to existing classifications of project delivery methods, these classes are data-driven typologies that represent how participants are procured and organized into a project team. The findings have implications as an alternative classification system in project delivery research and as guidance to owners considering their project delivery options.     

Industrialized construction in the Swedish infrastructure sector: core elements and barriers

Improving productivity and innovation is a central challenge in all industries, but particularly in construction where improvements have been slow. To meet this challenge, a recent investigation into the actions of Swedish government clients has recognized needs to improve planning during project procurement phases, increase numbers of turnkey contracts and raise industrialization of the sector. In response, the Swedish Transportation Administration has launched a research and innovation programme to foster an industrial approach and identify ways to increase the standardization of products and processes. However, increasing industrialization has been difficult to achieve in the project-based construction industry except in the process-based housing sector. Further, there has been little research on the concept of industrialized infrastructure construction and barriers to its implementation. Opinions and attitudes of clients, consultants and contractors in the infrastructure sector were investigated in relation to the core elements of industrialized construction, and the barriers hindering its development. Opportunities and obstacles related to both product and process standardization for continuous improvements and the relationships between clients and contractors are revealed. Hence, the implementation of industrialized construction requires tightly focused governance at the outset of projects and profound changes to established attitudes, norms and regulations.     

An empirical examination of project contractors' supply-chain cash flow performance and owners' payment patterns

Supply-chain (SC) cash flow performance is an essential component of SC performance management. Despite the panoply of approaches to SC cash flow modeling, relatively few published studies assess the effect of SC cash flow performance on a project contractor's financial performance. Little research thus explores the behavioral patterns in the project owner-contractor dyad in the context of payment-term negotiation for improving the SC cash flow performance of a project contractor. Using data from 42 Taiwanese construction project contracting corporations, this paper systematically quantifies the effects of SC cash flow performance on the financial performance of construction project contractors. Further analysis using data from 118 returned, usable surveys reveals important behavioral patterns of project owners regarding payment terms with project contractors during the contracting phase of construction projects. These behavioral patterns provide project contractors with a base for supporting implementation efforts for improving SC cash flow performance.     

Service management in housing refurbishment: a theoretical approach

It is unusual to find that housing refurbishment projects have been undertaken with a clear focus on customer orientation directed towards the tenants, or owners of cooperative flats or condominiums. Only recently have researchers in construction management begun to look closer at the relationship between contractors and customers. To assess the scope for customer orientation in the refurbishment industry, current thinking in service management is reviewed here in an attempt to identify principles with implications for housing refurbishment. There is a consensus among service management investigators that services are intangible; other often mentioned characteristics are heterogeneity, perishability, and the inseparability of production and consumption. Except for inseparability these characteristics are valid for refurbishment. Nevertheless, features such as the long turn-round time, the number of participants, the complexity and the uncertainty, distinguish housing refurbishment from most services. There is strong empirical support for the claim that customer satisfaction increases customer loyalty and gives the service producer a positive reputation, ultimately increasing profitability. It is concluded that this insight can be interpreted operationally for housing refurbishment projects, bearing in mind that the tenant or the owner of a cooperative flat is the customer's customer.     

Achieving best value in private finance initiative project procurement

The wherewithal of achieving best value in private finance initiative (PFI) projects and the associated problems therein are documented. In the UK, PFI has offered a solution to the problem of securing necessary investment at a time of severe public expenditure restraint. In PFI schemes, the public sector clients must secure value for money, while the private sector service providers must genuinely assume responsibility for project risks. A broad‐based investigation into PFI risk management informs the discussion in this paper. It is based on 68 interviews with PFI participants and a case study of eight PFI projects. The research participants comprised of contractors, financial institutions, public sector clients, consultants and facilities management organizations. The qualitative software Atlas.ti was used to analyse the textual data generated. The analysis showed that the achievement of best value requirements through PFI should hinge on: detailed risk analysis and appropriate risk allocation, drive for faster project completion, curtailment in project cost escalation, encouragement of innovation in project development, and maintenance cost being adequately accounted for. Factors that continue to challenge the achievement of best value are: high cost of the PFI procurement process, lengthy and complex negotiations, difficulty in specifying the quality of service, pricing of facility management services, potential conflicts of interests among those involved in the procurement, and the public sector clients' inability to manage consultants.     

An evaluation of the applicability of 4D CAD on construction projects

4D CAD models that integrate physical 3D elements with time, have been used to visualize construction processes in several projects worldwide. 4D models have been used and have been shown to have benefits over processes that span the entire lifecycle of a project such as collaboration with stakeholders, making design decisions, assessing project constructability, identifying spatial conflicts in construction and so on. Despite these benefits, several organizational and project-specific barriers have hindered the widespread adoption of 4D CAD. In order to reconcile the theoretical benefits of 4D models with the practical difficulties faced in implementation, there is an urgent need to explore the implementation of 4D models on construction sites as well as the perceptions of intended users/beneficiaries towards this implementation. This paper aims to address this need and contribute to our understanding of how 4D models must be introduced, positioned and implemented on construction sites, so as to maximize both their acceptability and their usefulness. We describe two 4D models of infrastructure projects and two 4D models of commercial projects that have been built and implemented. Through a process of structured and unstructured interviewing the paper gauges the response of project participants across various organizational levels on each of these projects as to the usefulness of 4D in project planning and control. Through qualitative and statistical analysis of the data we establish that 4D CAD is likely to be most beneficial in the project shaping or planning stage and in the construction stage. In the project shaping stage, 4D CAD is likely to be particularly useful in communicating construction plans and processes to clients, while during the construction phase, 4D CAD is likely to be particularly useful in comparing the constructability of work methods visually in order to detect conflicts or clashes, and as a visual tool for contractors, clients, subcontractors and vendors to review and plan project progress. Further, upper management and site workers are more likely to use and derive benefits from the visualization of processes using 4D given their lack of site related knowledge or skills, while construction professionals who are more construction-savvy are more likely to appreciate and benefit from the analytical and planning aids that 4D simulations provide during the construction phase. However, it is likely that despite these benefits 4D CAD models might not diffuse through the construction industry unless 4D modelling and analysis is integrated into existing project planning approaches. The paper concludes with a brief discussion on future 4D software development that seeks to bring about such integration and leverages the benefits of 4D CAD to bring about improved operational efficiencies on construction sites.     

Residential satisfaction assessment of a 1970s modernist housing community in Istanbul: searching for the reasons behind the preservation of a housing community’s current architectural status against the urban transformation movements affecting the entire city

Going against the mainstream popularity of high-rise housing developments dominating the Turkish construction market in the late twentieth century, Haluk Baysal and Melih Birsel collaboratively built the Istanbul Yesilkoy Housing Community project in 1973 using the principles of modern architecture. Although the modern lifestyle dominant in the design of this housing project did not emerge from the principles of life inherent to Turkish domestic architecture, this study examines how this project could remain resistant to the destructive force of a possible earthquake in a location where the land value is higher than many other districts of Istanbul. This study’s research question is whether or not the survival of this residential housing community could be attributed to residential satisfaction. The study’s research method was a residential satisfaction survey and factor analyses. The results showed that the continued existence of the residential community in the midst of the urban transformation movement is because the community satisfied its residents’ needs for safety, centrality, and neighbourliness.

     

公租房工程项目合同类型的选择

公租房项目工期紧任务重,工程内容构成复杂,需根据工程实际情况综合考虑各种因素,灵活运用多种合同类型,确保工程顺利实施。合理选择承发包双方都能接受的工程项目合同类型是公租房项目合同管理的关键一环,是保障公租房项目建设快速有序推进,实现较为理想的投资效益的重要手段。     

Effects of interpersonal relations on public sector construction contracts in Vietnam

Public owners and private contractors and consultants are expected to maintain arm’s length relationships with each other to avoid any accusation of corruption. In the context of public construction projects in Vietnam, this study examines: the relational contracting (RC) related behavioural patterns that lead to better interpersonal relations during the construction stage and at the end of the project among public project owners, and private contractors and consultants; and the extent to which better interpersonal relations affect project performance. Using a questionnaire survey, data were collected from public owners and private contractors and consultants in Vietnam. Correlation analysis shows that there exist several behavioural patterns that significantly affect interpersonal relations among project team members during the construction stage and at the end of the project, and the general harmony during the construction stage. It was also found that cost performance is significantly correlated with project harmony level. Schedule performance is significantly correlated with interpersonal relations between project team members during the construction stage, and at the end of the project. The findings indicate the important role that interpersonal relations play in project outcomes and vice versa. The behavioural patterns that are found to be significantly correlated with harmony during the construction stage and/or relationships among project team members suggest that concrete actions may be taken by owners, consultants and contractors to improve relationships, and thereby improve cost and schedule outcomes. It is recommended that owners, consultants and contractors adopt some of the behavioural patterns identified.     

Client satisfaction and quality management systems in contractor organizations

The construction industry is predominantly project based and quality is one of the client's prime concerns in their construction projects. Many clients, especially those in the Hong Kong public sector, require their contractors to have a Quality Management System (QMS) certified under ISO9000. Also, several contractors as well as clients themselves voluntarily implemented an ISO9000-based QMS in their respective organizations in order to target the various benefits perceived from such initiative. It was considered timely and worthwhile to explore the effectiveness of ISO9000-based QMSs in the Hong Kong. This paper portrays the key findings from a focused study that relate to the client satisfaction aspects from implementation of the ISO9000-based QMSs in the contractor organizations.     

A contractor pre-qualification model based on the quality function deployment method

Contractors play a significant role in construction projects and selection of the most appropriate contractor for the project is a critical decision for clients. The pre-qualification of construction contractors is accounted as a very important step in contractor selection for every project. The main purpose of pre-qualification is to identify an array of eligible contractors, which is required for post-qualification steps and further considerations. Although there have been numerous models for contractor pre-qualification, there are inadequate researches to present a contractor pre-qualification model with consideration of the project objectives or the project owner’s requirements. A new contractor pre-qualification model was developed with the aim of resolving this issue. This model employs the quality function deployment (QFD) method, and considers both the project owner’s requirements and the contractor’s abilities. The results reveal that consideration of the project objectives or the project owner’s requirements and expectations can influence contractor pre-qualification.