856 resultados para Rationalization of construction
Resumo:
The method of entropy has been useful in evaluating inconsistency on human judgments. This paper illustrates an entropy-based decision support system called e-FDSS to the solution of multicriterion risk and decision analysis in projects of construction small and medium enterprises (SMEs). It is optimized and solved by fuzzy logic, entropy, and genetic algorithms. A case study demonstrated the use of entropy in e-FDSS on analyzing multiple risk criteria in the predevelopment stage of SME projects. Survey data studying the degree of impact of selected project risk criteria on different projects were input into the system in order to evaluate the preidentified project risks in an impartial environment. Without taking into account the amount of uncertainty embedded in the evaluation process; the results showed that all decision vectors are indeed full of bias and the deviations of decisions are finally quantified providing a more objective decision and risk assessment profile to the stakeholders of projects in order to search and screen the most profitable projects.
Resumo:
The construction sector is under growing pressure to increase productivity and improve quality, most notably in reports by Latham (1994, Constructing the Team, HMSO, London) and Egan (1998, Rethinking Construction, HMSO, London). A major problem for construction companies is the lack of project predictability. One method of increasing predictability and delivering increased customer value is through the systematic management of construction processes. However, the industry has no methodological mechanism to assess process capability and prioritise process improvements. Standardized Process Improvement for Construction Enterprises (SPICE) is a research project that is attempting to develop a stepwise process improvement framework for the construction industry, utilizing experience from the software industry, and in particular the Capability Maturity Model (CMM), which has resulted in significant productivity improvements in the software industry. This paper introduces SPICE concepts and presents the results from two case studies conducted on design and build projects. These studies have provided further in-sight into the relevance and accuracy of the framework, as well as its value for the construction sector.
Resumo:
The complexity of construction projects and the fragmentation of the construction industry undertaking those projects has effectively resulted in linear, uncoordinated and highly variable project processes in the UK construction sector. Research undertaken at the University of Salford resulted in the development of an improved project process, the Process Protocol, which considers the whole lifecycle of a construction project whilst integrating its participants under a common framework. The Process Protocol identifies the various phases of a construction project with particular emphasis on what is described in the manufacturing industry as the ‘fuzzy front end’. The participants in the process are described in terms of the activities that need to be undertaken in order to achieve a successful project and process execution. In addition, the decision-making mechanisms, from a client perspective, are illustrated and the foundations for a learning organization/industry are facilitated within a consistent Process Protocol.
Resumo:
In financial decision-making processes, the adopted weights of the objective functions have significant impacts on the final decision outcome. However, conventional rating and weighting methods exhibit difficulty in deriving appropriate weights for complex decision-making problems with imprecise information. Entropy is a quantitative measure of uncertainty and has been useful in exploring weights of attributes in decision making. A fuzzy and entropy-based mathematical approach is employed to solve the weighting problem of the objective functions in an overall cash-flow model. The multiproject being undertaken by a medium-size construction firm in Hong Kong was used as a real case study to demonstrate the application of entropy. Its application in multiproject cash flow situations is demonstrated. The results indicate that the overall before-tax profit was HK$ 0.11 millions lower after the introduction of appropriate weights. In addition, the best time to invest in new projects arising from positive cash flow was identified to be two working months earlier than the nonweight system.
Resumo:
In financial decision-making, a number of mathematical models have been developed for financial management in construction. However, optimizing both qualitative and quantitative factors and the semi-structured nature of construction finance optimization problems are key challenges in solving construction finance decisions. The selection of funding schemes by a modified construction loan acquisition model is solved by an adaptive genetic algorithm (AGA) approach. The basic objectives of the model are to optimize the loan and to minimize the interest payments for all projects. Multiple projects being undertaken by a medium-size construction firm in Hong Kong were used as a real case study to demonstrate the application of the model to the borrowing decision problems. A compromise monthly borrowing schedule was finally achieved. The results indicate that Small and Medium Enterprise (SME) Loan Guarantee Scheme (SGS) was first identified as the source of external financing. Selection of sources of funding can then be made to avoid the possibility of financial problems in the firm by classifying qualitative factors into external, interactive and internal types and taking additional qualitative factors including sovereignty, credit ability and networking into consideration. Thus a more accurate, objective and reliable borrowing decision can be provided for the decision-maker to analyse the financial options.
Resumo:
The aim of this chapter is to examine what the construction sector brings to our understanding of the procurement of complex performance. The chapter is divided into the following parts: fi rst, an overview of the various matters that contribute to the complexity of construction procurement is provided. Second, the most important contractual incentive schemes found in construction contracts are discussed, and this is followed by, third, an examination of the changes associated with the shift towards procuring complex performance (PCP) (service provision). Fourth, the main findings of the authors’ recent research on PCP contracts are summarised, followed by the conclusion. It should be noted that the procurement of services is referred to as ‘PCP’ in this chapter.
Resumo:
It is considered that systemisation, the use of standard systems of components and design solutions, has an effect on the activities of the designer. This paper draws on many areas of knowledge; design movements, economic theory, quality evaluation and organisation theory to substantiate the view that systemisation will reduce the designer's discretion at the point of design. A methodology to test this hypothesis is described which will be of use to other researchers studying the social processes of construction organisations.
Resumo:
From its roots in strategic management theory, stakeholder management has been adopted by the construction management academic community and applied as a valid paradigm around which research work has been generated aiming to improve project effi ciencies and effectiveness. However, academics have argued that stakeholder management should move away from purely theoretical discussions and engage more with the realities of construction project work. This paper re-appraises the stakeholder management concept for the construction domain by re-thinking some of the fundamental principles and ideals present within the more general stakeholder theory literature. It engages with issues which researchers have arguably failed to acknowledge and calls for a re-evaluation of construction stakeholder management research by presenting a review around four distinctive themes: the moral obligations of engaging with stakeholders against the business and efficiency driven imperatives of construction organisations; the contrast between theoretical abstractions and empirically grounded research; the tensions between theoretical convergence versus calls for multiple and divergent perspectives on stakeholder management and the practicalities of conducting stakeholder management in the construction domain. Such a critical re-appraisal of stakeholder management thinking both generates new lines of enquiry and promises to help inform and shape current and future industry practice.
Resumo:
There is limited understanding of the role of services in the wave of globalisation and how the strengths of the UK service sector help to respond to the challenge of global competition. The way in which the construction export data are collected does not reflect the impact of globalisation and the changes in the construction business environment, such as increasing foreign ownership, foreign affiliates, and changing forms of procurement. The paper describes construction service exports, how they are collected and classified, highlighting the challenges of recording the export performance of construction services in a changing world. A case for change is made to ensure the collection of statistics better reflects the role of construction professional services
Resumo:
The past decade has witnessed a sharp increase in published research on energy and buildings. This paper takes stock of work in this area, with a particular focus on construction research and the analysis of non-technical dimensions. While there is widespread recognition as to the importance of non-technical dimensions, research tends to be limited to individualistic studies of occupants and occupant behavior. In contrast, publications in the mainstream social science literature display a broader range of interests, including policy developments, structural constraints on the diffusion and use of new technologies and the construction process itself. The growing interest of more generalist scholars in energy and buildings provides an opportunity for construction research to engage a wider audience. This would enrich the current research agenda, helping to address unanswered problems concerning the relatively weak impact of policy mechanisms and new technologies and the seeming recalcitrance of occupants. It would also help to promote the academic status of construction research as a field. This, in turn, depends on greater engagement with interpretivist types of analysis and theory building, thereby challenging deeply ingrained views on the nature and role of academic research in construction.
Resumo:
The traditional economic approach for appraising the costs and benefits of construction project Net Present Values involves the calculation of net returns for each investment option under different discount rates. An alternative approach consists of multiple-project discount rates based on risk modelling. The example of a portfolio of microgeneration renewable energy technology (MRET) is presented to demonstrate that risks and future available budget for re-investment can be taken into account when setting discount rates for construction project specifications in presence of uncertainty. A formal demonstration is carried out through a reversed intertemporal approach of applied general equilibrium. It is demonstrated that risk and the estimated available budget for future re-investment can be included in the simultaneous assessment of the costs and benefits of multiple projects.