Benefit evaluation for off‐site production in construction

Evaluating to what extent a component or building system should be produced off‐site is inadequate within the industry. The potential benefits of off‐site production (OSP) are commonly cited when justifying an OSP approach, yet holistic and methodical assessments of the applicability and overall benefit of these solutions, to a particular project, have been found to be deficient. Common methods of evaluation simply take material, labour and transportation costs into account when comparing various options, often disregarding other cost‐related items such as site facilities, crane use and rectification of works. These cost factors are usually buried within the nebulous preliminaries figure, with little reference to the building approach taken. Further, softer issues such as health and safety, effects on management and process benefits are either implicit or disregarded within these comparison exercises. Yet it is demonstrated that these issues are some of the most significant benefits of OSP. A series of case studies demonstrated that evaluation focus is almost solely on direct material and labour costs of components, without explicit regard for the wider cost or soft issue implications of OSP on a project. The paper argues that until evaluation is more holistic and value‐based rather than cost‐based, OSP uptake in construction will be slow.     

Defects in offsite construction: timber module prefabrication

The construction industry is based on craftsmanship. Quality control and assurance procedures applied in manufacturing cannot usually be readily applied in construction, where there are higher degrees of uniqueness in each project. One category of companies, industrialized housebuilders, is attempting to bridge some of the gaps between construction and manufacturing. These companies prefabricate building modules for later assembly at the building site. Since they are wholly responsible for large parts of the building process, these companies have greater opportunities to control and improve quality in a more consistent way than ordinary construction companies. Thus, it could be hypothesized that the frequency and severity of defects should be lower in industrialized housing than in ordinary construction. The aim of the study presented here is to examine this hypothesis by measuring and characterizing defects in industrialized housing. The design and manufacturing processes at two Swedish timber module prefabrication firms has been analysed through interviews, site visits and document reviews. Quality audits from three phases of the building process were compiled, analysed and categorized to provide statistical measures of defects in industrialized housing. The results show that the case study companies are better in terms of product quality than conventional housing.     

The challenges of creating actionable knowledge: an action research perspective

Academia has a critical role in developing new knowledge which construction industry practitioners need to envision, undertake and sustain successful innovation. The new knowledge produced by academia, however, often does not satisfy the needs of practitioners. This unsatisfactory state of affairs is frequently taken to be the consequence of the cultural, motivational and operational differences between the two communities. Actionable knowledge is presented as a useful concept which can fuse the expectations, contributions and outputs of academia and practitioners. Within this context, action research is argued to be an appropriate methodology to develop successful actionable knowledge. Results from an action research project are given which provide researchers and practitioners greater understanding of the key factors that shape the degree to which action research produces actionable knowledge: change focus, collaboration capabilities and systematic process. The criteria intrinsic to Mode 2 research (Gibbons et al., 1994 Gibbons, M., Limoges, C., Nowotny, H., Schwartz, S., Scott, P. and Trow, M. 1994. The New Production of Knowledge: The Dynamics of Science and Research in Contemporary Societies, London: Sage.  [Google Scholar]) are demonstrated to have utility in evidencing actionable knowledge. The implication for policy is that there is a need to develop and use appropriate actionable knowledge frameworks and measures to design funding calls, and to evaluate research proposals and outputs.     

Construction management and economics: the epistemology of a multidisciplinary design science

Research in the field of construction management and economics (CME) can be characterized as a multidisciplinary design science. Results from the sciences and humanities are necessary inputs for this field of research that deals with design, production and operation of the built environment. The output of CME research as multidisciplinary design science consists of three types of solution concepts: empirical generalizations based on statistical data analysis (technological laws), concepts that specify what to do, if a certain result is to be attained under given circumstances (functional rules), and insights in the interrelationship between design, production and operation of the built environment and social practice (socio‐technological understanding). Scientific justification of these solution concepts is obtained through testing them in the specific context of the built environment.     

Total factor productivity growth accounting in the construction industry of Singapore

Total factor productivity (TFP) determines long‐term economic growth and is a comprehensive industry‐level productivity measure. This paper proposes Jorgenson's method as an appropriate TFP measurement for the construction industry. The method is less restrictive than the conventional Chau's approach, as it does not impose the Hick Neutral Technical Change assumption. Jorgenson's method is then applied to estimate TFP growth in the construction industry of Singapore over 1984–1998. TFP growth is found down by 1.53% per annum over this period, indicating that the performance of TFP in the construction industry lags behind the rest of economy. TFP growth is also found to be fluctuating over time and tends to move in tandem with the construction business cycle.

As a monitor of progress towards TFP achievement, factors influencing TFP growth in the construction industry of Singapore over 1984–1997 are identified. Seven factors are found to be significantly related to TFP growth. Among them, economies of scale, R&D by the industry, investment allowance granted and labour unions are leading contributors to TFP growth; while foreign worker, construction accidents and pre‐cast are major hampers.

The general methodology presented in this study can be applied to other countries. Future studies are required to find appropriate indicators for factors unquantified.     

Reducing the use of resources in medium-sized Swedish construction enterprises: production managers’ views

What construction firms do—and do not do—to reduce the use of resources in construction projects is explored by adopting production managers’ views of their firms’ onsite activities. A literature review and empirical data are combined; 15 production managers have been asked how they perceived their company’s compliance with 31 recommendations to reduce the use of resources. The managers perceived their firms to primarily focus on identifying their customers’ real needs, stimulating employees to undertake further education, and striving for long-term customer–supplier relationships. In contrast, they perceived that less attention was directed to making use of all of the week’s hours, to supporting their main suppliers in their development, and planning feedback and training after project completion. The use of resources is examined by focusing on the perceived low priority given to gathering information and knowledge, as well as to reducing time and the need for long-term relationships with customers in contrast to short-term relationships with suppliers. The managers adopted a project-specific approach mainly to the use of material resources. A more holistic view of resources could enable the development of novel solutions in construction.     

道路与桥梁工程专业生产实习教学实践与改革探索

文章对西南石油大学土木工程与建筑学院的传统生产实习方式和驻地实习这一新的实习方式进行了对比分析,指出驻地实习方式是工科学生强化工程能力训练的有效手段,它能提高学生的学习积极性,锻炼学生交流沟通的能力,增加学生就业机会,值得探索和推广。     

粉煤灰砖生产工艺技术综述

当前国内建筑施工中大量使用轻质、高强、绿色环保以及复合型新型墙体材料。粉煤灰砖是墙体材料中的主导产品,它符合节能、环保、促进墙体材料改革的目标,有着广阔的发展应用前景。国内粉煤灰生产工艺主要有烧结工艺,蒸压工艺,免烧免蒸压工艺等。常温发泡砖仍处于研发中。     

谈山西“人口半城镇化”问题及对策建议

对山西省城镇化工作中较为突出的"人口半城镇化"问题进行了研究,按照因地制宜、以人为本、科学发展的原则,从人口管理、土地管理、生态环境、行政管理等方面提出了有力的解决措施,以推动城镇化的发展。