Predicting risk of water quality failures in distribution networks under uncertainties using fault-tree analysis

The water quality in a distribution system is affected by many factors, including operational and environmental conditions as well as the condition in and around the distribution network. Lack of reliable data as well as knowledge gaps with respect to the impact of these factors on water quality make the quantification of water quality failure risk very challenging. Furthermore, the variability inherent in (sometimes) thousands of kilometers of distribution pipes presents added complexities. Major modes of water quality failures can be classified into intrusion of contaminants, regrowth of bacteria (biofilm), water treatment breakthrough, leaching of chemicals or corrosion products from system components, and permeation of organic compounds through plastic pipes. Deliberate contamination and negligence of operators have in recent years become an added concern. In earlier works by Sadiq et al. (2004 Sadiq, R., Kleiner, Y. and Rajani, B. 2004. Aggregative risk analysis for water quality failure in distribution networks. Journal of Water Supply Research and Technology: Aqua, 53(4): 241–261. [Web of Science ®] , [Google Scholar], 2007 Sadiq, R., Kleiner, Y. and Rajani, B. 2007. Water quality failures in distribution networks – risk analysis using fuzzy logic and evidential reasoning. Risk Analysis – An International Journal, 27(5): 1381–1394. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]), an aggregative risk analysis approach using hierarchical structure was proposed to describe all possible mechanisms of contamination. In this paper a similar structure is used as a basis for a fault-tree approach. While fault-tree analysis is widely used for many engineering applications, in this paper we specifically explore how interdependencies among factors might impact analysis results. Two types of uncertainties are considered in the proposed analysis. The first is related to the likelihood of risk events, and the second is related to non-linear dependencies among risk events. Each basic risk event (input factor) is defined using a fuzzy probability (likelihood) to deal with its inherent uncertainty. The dependencies among risk events are explored using Frank copula and Frechet's limit. The proposed approach is demonstrated using two well-documented episodes of water quality failures in Canada, namely, Walkerton (ON) and North Battleford (SK).     

Planning and the communal state: interpreting community participation in Caracas

The paper adopts an interpretive institutionalist framework [Hay (2011 Hay, Colin. 2011. “Interpreting Interpretivism Interpreting Interpretations: The New Hermeneutics of Public Administration.” Public Administration 89 (1): 167–82. doi:10.1111/j.1467-9299.2011.01907.x.[Crossref], [Web of Science ®] [Google Scholar]), “Interpreting Interpretivism Interpreting Interpretations: The New Hermeneutics of Public Administration.” Martin (2015 Martin, Graham. 2015. “‘Ahora tienen que escucharnos’ [now they have to listen to us]: Actors’ Understandings and Meanings of Planning Practices in Venezuela’s ‘Participatory Democracy’.” PhD thesis, Cardiff University. http://orca.cf.ac.uk/77661/. [Google Scholar]), “‘Ahora tienen que escucharnos’ [now they have to listen to us]: Actors’ Understandings and Meanings of Planning Practices in Venezuela’s ‘Participatory Democracy.” PhD Thesis, Cardiff University, to unpack participants’ involvement in communal councils (CCs) and a commune, two Venezuelan reforms seeking to incorporate citizens into planning processes. The paper focuses on how participants in La Silsa, an informal neighbourhood in Caracas, understood and enacted upon community planning opportunities provided by these new councils. Municipal and national government staff and finance heavily supported La Silsa’s emerging commune and CCs. Despite the national government’s rhetoric of ‘constructing a new socialist, communal state’, the article identifies several challenges need to be overcome to successfully shift from existing representative institutional/governmental arrangements towards more participatory repertoires. The article’s findings mirror those of other empirical studies of Latin America’s democratic innovations: citizen participation strengthens representative governmental arrangements, rather than replace them with normative alternatives.     

The Shape of Things to Come: New Urbanism,the Grid and the Cul-De-Sac

There is much debate in the UK, North America and Australia within both crime prevention and planning concerning New Urbanism and the design of suburban housing layouts. New Urbanism promotes high-density, mixed-use residential developments in ‘walkable’ neighbourhoods close to public transport, employment and amenities. One significant factor is New Urbanism's support for permeability and the preference of the grid street layout over the cul-de-sac (Morrow-Jones et al., (2004) Morrow-Jones, H., Irwin, E. and Roe, B. 2004. Consumer preference for neotraditional neighbourhood characteristics. Housing Policy Debate, 15(1): 171–202. [Taylor & Francis Online], [Web of Science ®] [Google Scholar]. The authors present the evidence as it relates to the grid and the cul-de-sac across a range of inter-disciplinary issues such as crime, walkability, social interaction, travel behaviour, traffic safety, cost and sustainability and housing preferences. This paper provides a brief history of the grid and cul-de-sac, discusses their respective strengths and weaknesses and concludes that any ‘one-size-fits-all’ approach is myopic and simplistic. It calls for a more holistic approach to understanding the localized and contextual dimension to suburban street layouts and how they may affect human behaviour. The paper highlights key areas for future research and calls for more inter-disciplinary debate and cooperation, particularly between environmental criminologists, planners and town centre managers.     

Planning for deep-rooted problems: What can we learn from aligning complex systems and wicked problems?

An earlier generation of planners turned to Rittel & Webber’s 1973 Rittel, H. W. J., & Webber, M. M. (1973). Dilemmas in a general theory of planning. Policy Sciences, 4, 155–169. doi:10.1007/BF01405730[Crossref], [Web of Science ®] , [Google Scholar] conception of “wicked problems” to explain why conventional scientific approaches failed to solve problems of pluralistic urban societies. More recently, “complex systems” analysis has attracted planners as an innovative approach to understanding metropolitan dynamics and its social and environmental impacts. Given the renewed scholarly interest in wicked problems, we asked: how can planners use the complex systems approach to tackle wicked problems? We re-evaluate Rittel and Webber’s arguments through the lens of complex systems, which provide a novel way to redefine wicked problems and engage their otherwise intractable, zero-sum impasses. The complex systems framework acknowledges and builds an understanding around the factors that give rise to wicked problems: interaction, heterogeneity, feedback, neighbourhood effects, and collective interest traps. This affinity allows complex systems tools to engage wicked problems more explicitly and identify local or distributed interventions. This strategy aligns more closely with the nature of urban crises and social problems than the post-war scientific methodologies about which Rittel and Webber had grown increasingly sceptical. Despite this potential, planners have only belatedly and hesitantly engaged in complex systems analysis. The barriers are both methodological and theoretical, requiring creative, iterative problem framing. Complex systems thinking cannot “solve” or “tame” wicked problems. Instead, complex systems first characterize the nature of the wicked problems and explore plausible pathways that cannot always be anticipated and visualized without simulations. The intersection of wicked problems and complex systems presents a fertile domain to rethink our understanding of persistent social and environmental problems, to mediate the manifold conflicts over land and natural resources, and thus to restructure our planning approaches to such problems.     

Changing Landscapes,Changing Landscape's Story

Abstract

Visual surrogates have been widely used for solving environment related issues. Researchers now have concern over the validity of surrogates. Human perception is multi-modal (Wohlwill, 1976 Wohlwill, J. F. 1976. “Environmental aesthetics: the environment as a source of affect”. In Human Behavior and Environment: Advances in Theory and Research, Edited by: Altman, I. and Wohlwill, J. F. New York: Plenum Press. [Crossref] , [Google Scholar]; Ittelson, 1973 Ittelson W. Environment and Cognition Seminar Press New York 1973  [Google Scholar]) and motion is an essential aspect in the perceptual process (Gibson, 1979 Gibson, J. J. 1979. The Ecological Approach to Visual Perception, Boston, MA: Houghton Mifflin.  [Google Scholar]). Therefore, a surrogate has to be able to represent the dynamic elements in the environment and more realistically reflect human environmental experience. The purpose of this study was to examine the validity of videos and slides as visual surrogates for representing dynamic environment. The validity of the surrogates was verified by comparing subjects' perceptual responses to on-site and simulated situations. The perceptual assessments included emotional, cognitive, behavioural and preference responses. The results indicated that on-site participants' emotional responses and preferences are significantly stronger than those of video and slide viewers. In addition, on-site participants' and video viewers' cognitive and behavioural responses were significantly higher than those of slide viewers. Overall, the validity of videos and slides for representing waterscapes was not supported.     

Putting theory to work: the use of theory in construction research

Attention to epistemology, theory use and citation practices are all issues which distinguish academic disciplines from other ways of knowing. Examples from construction research are used to outline and reflect on these issues. In doing so, the discussion provides an introduction to some key issues in social research as well as a reflection on the current state of construction research as a field. More specifically, differences between positivist and interpretivist epistemologies, the role of theory in each and their use by construction researchers are discussed. Philosophical differences are illustrated by appeal to two published construction research articles by Reichstein et al. and Harty on innovation (Reichstein, Salter and Gann, 2005 Reichstein, T., Salter, A.J. and Gann, D.M. (2005) Last among equals: a comparison of innovation in construction, services and manufacturing in the UK. Construction Management and Economics, 23, 631–644.10.1080/01446190500126940[Taylor &; Francis Online] , [Google Scholar]; Harty, 2008 Harty, C. (2008) Implementing innovation in construction: contexts, relative boundedness and actor-network theory. Construction Management and Economics, 26, 1029–1041.10.1080/01446190802298413[Taylor &; Francis Online] , [Google Scholar]). An analysis of citations for each highlights different cumulativity strategies. The potential contribution of mixed research programmes, combining positivist and interpretivist research, is evaluated. The paper should be of interest to early researchers and to scholars concerned with the ongoing development of construction research as an academic field.     

Strategic Planning for Long-Term Flood Risk Management: Some Suggestions for Learning How to Make Strategy at Regional and Local Level

Often, discussions about improving long-term Flood Risk Management (FRM) refer to spatial planning as one of the most promising policy instruments (non-structural measures), especially after flood disasters like in Dresden in August 2002. However, up to now, evidence is limited that spatial planning is used intensively and systematically for long-term FRM, for instance, to reduce vulnerability in flood-prone areas by controlling developments on floodplains and providing development possibilities in non-hazardous areas (Burby et al., 2000 Burby, R. J., Deyle, R. E., Godschalk, D. R. and Olshansky, R. B. 2000. Creating hazard resilient communities through land-use planning. Natural Hazards Review, 1(2): 99–106. [Crossref] [Google Scholar]). Based on the literature on strategic spatial planning (e.g., Albrechts, 2004a Albrechts, L. 2004a. Strategic (spatial) planning re-examined. Environment and Planning B: Planning and Design, 31: 743–758. [Crossref], [Web of Science ®] [Google Scholar]; Bryson, 2004 Bryson, J. M. 2004. “Strategic planning for public and nonprofit organizations.”. In A Guide to Strengthening and Sustaining Organizational Achievement, San Francisco: Jossey-Bass.  [Google Scholar]; Healey, 2007 Healey, P. 2007. “Urban complexity and spatial strategies”. In Towards a Relational Planning for Our Times, London: Routledge.  [Google Scholar]) and risk management (e.g., Klinke & Renn, 2002 Klinke, A. and Renn, O. 2002. A new approach to risk evaluation and management: risk-based, precaution-based, and discourse-based strategies. Risk Analysis, 22(6): 1071–1094. [Crossref], [PubMed], [Web of Science ®] [Google Scholar]), this paper presents normative conclusions from case studies conducted in Dresden and London on how to use strategic planning for improving long-term FRM.

The twin hazards of uncertainty and disagreement form an essential context for plannin?s ambitions of shaping the future. In practice, planners may retreat to shorter-range decisions with more limited consequences. Or they may resort to public relations devices that may gain agreement in superficial ways. Still another response is to hide behind technical analyses that are not fully shared with the public, neither revealing the true level of uncertainty nor exposing judgements to potential disagreements. Better methods are clearly desired for professional leadership regarding the future.

(Myers, 2001 Myers, D. 2001. Symposium: putting the future in planning. Introduction. JAPA: Journal of the American Planning Association, 67(4): 365–367. [Taylor & Francis Online], [Web of Science ®] [Google Scholar]: 365)

Evaluation of building code compliance in Mexico City: mid-rise dwellings

The Mexico City Building Code (MCBC-2004 MCBC. (2004). Reglamento de Construcciones del Distrito Federal, Gaceta Oficial del Distrito Federal, 29 de enero de 2004. In Spanish. [Google Scholar]) – Reglamento de Construcciones del Distrito Federal, Gaceta Oficial del Distrito Federal, 29 MCBC. (2004). Reglamento de Construcciones del Distrito Federal, Gaceta Oficial del Distrito Federal, 29 de enero de 2004. In Spanish. [Google Scholar] de enero de 2004 MCBC. (2004). Reglamento de Construcciones del Distrito Federal, Gaceta Oficial del Distrito Federal, 29 de enero de 2004. In Spanish. [Google Scholar] in Spanish – is a state-of-the-art code; the most comprehensive and advanced set of requirements in the country; and it serves as a model for codes in Mexico's regions. However, many recently built mid-rise dwellings seem too weak to withstand earthquakes, with evident structural deficiencies. Insufficient official mechanisms exist for supervising the design and construction of such new structures. This study evaluates current practice and compares it with the guidelines of the MCBC-2004 using a sample of structures of 150 buildings constructed after 2004. Structural analysis and design revisions were made for a subset of 20 buildings. This study confirms that a large number of new buildings in Mexico City do not have a reliable record of technical information. Therefore, it is difficult to reanalyse buildings to assess their earthquake performance. Many buildings have limited information making it impossible to verify their structural seismic behaviour. The analyses performed for those buildings with available information show that many would have inadequate performance during an intense earthquake, as they do not meet the minimum requirements in the MCBC-2004. To improve governance and actual outcomes, an institute is needed to improve construction practices and code enforcement particularly for residential buildings.     

Spatial Spillovers of Land Use Regulation in the United States

Evidence of spatial dependence in land use regulatory levels was first found in Brueckner (1998 Brueckner, J. (1998) Testing for strategic interaction among local governments: The case of growth controls, Journal of Urban Economics, 44, pp. 438–467.[Crossref], [Web of Science ®] , [Google Scholar]) for California cities. Recent research has not incorporated this consideration despite the considerable consequences of the relationship. We seek to expand the empirical find ings to a current, larger and more diverse data-set for municipalities across the USA. Analyzing regulatory levels and their determinants from over 2000 municipalities, we find strong evidence of spatial dependence at the local level even after controlling for geographic and political influences. This suggests that political competition, rather than welfare maximization exclusively, may be influencing the level of regulations adopted.     

Reading Through a Plan

Problem: Planners may read plans often, but the profession continues to view the interpretation of plan content as something that is either too obvious or too unimportant to require explicit discussion. Plans are seldom adequately interpreted. This is regrettable because plans contain a rich variety of content and meaning.

Purpose: This article calls for planners to “read through” plans, not just to grasp their essential ideas or the means of implementing those ideas, but also to perceive additional levels of meaning relating to a) a plan's place within a larger intellectual sphere, b) a plan's statement on the social and political values of the time, and c) a plan as a part of the history of the planning profession and the life of cities.

Methods: I propose a visual approach to plan reading descended from Panofsky's (1939 Panofsky, E. 1939. Studies in iconology: Humanistic themes in the art of the Renaissance, New York, NY: Harper and Row.  [Google Scholar]) theory of iconology and use this to examine three very different plans that describe different size cities (small, large, very large) during different periods over the past 80 years (the 1930s, 1960s, 2000s). I analyze three levels of meaning in each plan: its factual meaning, or “plain sense” (Mandelbaum, 1990 Mandelbaum, S. J. 1990. Reading plans. Journal of the American Planning Association, 56(3): 350–358. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]); its contextual meaning, or relation to political, social, economic, and physical conditions; and its temporal meaning, or setting within the scope of observations made by other plan readers in the perspective of elapsed time.

Results and conclusions: Factual readings show that information may be found in diverse aspects of a plan document, from seemingly superficial aspects like its cover to unarguably central elements such as recommendations. Factual readings depend on understanding the relationships among different elements, and reveal information about the plan and its framers that may not otherwise be readily apparent. Contextual readings show us that plan recommendations are as much a product of contemporary conditions and norms as they are of plan-specific “survey and diagnosis” (Nolen, 1936 Nolen, J. 1936. Comprehensive city plan for Dubuque, Iowa, Dubuque, IA: City Planning and Zoning Commission.  [Google Scholar]). This raises the question of whether plan quality is to be judged only in terms of skillful execution of concerns of the day or whether innovation is also important. Temporal readings reveal that plans and planning have changed dramatically over time, simultaneously confirming and questioning the conventional wisdom of planning history.

Takeaway for practice: Many planners read plans on a regular basis, and plans continue to constitute the major printed currency of the planning profession. Both plans and planning will benefit if planners become more discerning readers of the profession's principal idea vessels. Formal plan interpretation is rare, but each planner can become a better plan interpreter.

Research support: None.     

Seismic retrofit of GLD shear wall structures in Singapore

This study is concerned with the experimental investigation into the seismic behaviour and retrofitting of gravity-load-designed reinforced-concrete (RC) shear wall structures in Singapore. These structures are designed according to the British Standard (BS8110 1985 BS8110. 1985. Structural use of concrete parts 1, 2 and 3, London: British Standards Institution.  [Google Scholar]). For this purpose, 1/5 scaled models (with and without retrofitting), representing the lower critical regions of a 25-story RC shear wall structure, were tested under cyclic loadings. Test results showed that the shear wall failed at the base due to shear and that the pushover test provides a simplified representation of the cyclic test. Retrofitting the wall with GFRP (glass fibre reinforced polymer) system resulted in improved performances of up to 20% to 30% higher ultimate load capacity and displacement. The study provides an insight into the seismic behaviour of such structures and the mechanism of the proposed retrofitting scheme for improving the structural resistance to seismic loads.     

Dialectics of Power: The Case of Tulihta Land-use Agreement

Case studies of planning which involve criminal corruption are rare. The article presents a Finnish court case known as “Tulihta”, concerning the breach of a land purchase contract and treachery in the preparation of the detailed plan for the land property in question, during 1989–1993. The case is analysed from the power perspective by using a framework developed by Mäntysalo and Rajaniemi (2003 Mäntysalo, R. and Rajaniemi, J. 2003. Vallan ulottuvuuksia maankäytön suunnittelussa. Synteesi, 22(3): 117–136.  [Google Scholar]). In the framework, two sets of binary characteristics of power, namely power as control and as ability, and explicit and implicit power, are combined into a horizontal-vertical field. The case analysis is aimed to test the applicability of the framework, as well as to reveal the manifold aspects of power at play in a land-use planning process.     

Energy performance sensitivity of a net-zero energy home to design and use specifications

The purpose of this report is to test the sensitivity of the energy performance of the National Institute of Standards and Technology (NIST)'s Net Zero Energy Residential Test Facility (NZERTF) design to variation in the assumed specifications of occupant behaviour and building design characteristics using whole building energy simulations. The analysis includes a total of 128 EnergyPlus (E+) simulations (DOE 2013 Department of Energy (DOE), Building Technologies Program. 2013. EnergyPlus energy simulation software version 8.0.0. http://apps1.eere.energy.gov/buildings/energyplus/. [Google Scholar]) considering two levels for each of the seven factors that could impact the energy performance of the NZERTF: building design, air leakage, occupant behaviour, weather, building orientation, and heating and cooling setpoint temperatures. The results for each combination of the seven factors are analysed to determine the magnitude and significance of changing these factors, and the interaction effects between the factors. There is particular focus on the building design results to determine if the energy performance of the NZERTF is more or less stable than that of typical residential construction in Maryland.     

The reconstruction of housing in Palestine 1993–2000: a case study from the Gaza Strip

In the Palestinian Territories, housing is thought to be amongst the most difficult problems facing the National Authority (PNA) (Al‐Agha, 1997 Al‐Agha Z (1997) A national outlook for housing in Palestine in: A. B. Zahlan (Ed.) Reconstruction of Palestine, Urban and Rural Development (London, Kegan Paul)  [Google Scholar], p. 3). Increased Israeli settlements, the large size of Palestinian families, the deteriorating economic situation, the lack of national banks operating in the field of housing, the presence of refugee settlements containing over 1.2 million people, the Israeli state's policy of residential demolition and land confiscation have all combined to present a severe obstacle to urban reconstruction in the region. In an attempt to address these issues and to make some progress towards realising the estimated 180 000 housing units required by the Palestinian people, the Palestinian Housing Council (PHC) was established in 1992 (Abd Alhadi, 1994 Abd Alhadi, R (1994) Construction and Housing in the West Bank and (Gaza) Strip (Geneva, United Nations Commission on Trade and Development)  [Google Scholar]; Ziara, 1997 Ziara M (1997) The Palestinian Ministry of Housing. Challenging and opportunities in A. B. Zahlan (ed.) Reconstruction of Palestine, Urban and Rural Development (London, Kegan Paul)  [Google Scholar]). Although it has had some success, the organisation has been plagued by reports of internal dissent and disputes with its beneficiaries. This paper seeks to cast some light on these controversies by focusing on the PHC's role in the Elkarama Housing Project in the Gaza Strip during the period 1993 to 2000.1 Here it must be emphasised that this paper does not claim to provide an analysis of the current situation in Gaza. The authors acknowledge that conditions in Palestine are extremely fluid and have, to a great degree, overtaken the issues considered above. In examining this rapidly‐evolving environment, however, it is valuable to reflect upon recent changes and, while recognising the acute systemic problems that Palestinian administrators face, to offer critical assessments of domestic policy decisions and their outcome. View all notes It will first outline the broader context in which public institutions within the Gaza Strip operate before offering an account of the structure and background of the PHC. It will then consider Elkarama itself and will conclude by summing up the various factors that have determined the project's outcome. Finally, the paper will offer some tentative recommendations for improved housing provisions within the Gaza Strip in the future.     

Cultural diversity and sensitivity in public estate renewals: evidence from an Australian longitudinal study

Abstract

Social mixing has been part of government policies regarding estate renewals in many countries. It is mostly achieved through tenure diversification, such as introducing privately owned and rented dwellings. Concurrently, in many residualized social housing sectors, larger shares of tenants now have high and complex needs, including recently settled refugees. Therefore, social and spatial manifestations of multiculture have become more complex. Consequently, a non-tenure-related form of social mixing, primarily one of cultural difference, occurs. This article considers the unintended effects of wider policies around resettlement of refugees in the context of estate renewal. Considering Wacquant et al.’s (2014 Wacquant, L., Slater, T. & Borges Pereira, V. (2014) Territorial stigmatization in action, Environment and Planning A: Economy and Space, 46, pp. 1270–1280.[Crossref], [Web of Science ®] , [Google Scholar], Territorial stigmatization in action, Environment and Planning A: Economy and Space, 46, pp. 1270–1280) discussions of dissimulation and microdifferences, it reflects on the experiences of residents living on estates that are currently undergoing renewal in suburban Adelaide, South Australia, and reports on tensions that sometimes emerge between long-established and more recently settled residents as well as efforts (by managing authorities, support services and the residents) to foster cross-cultural engagement and cultural sensitivity on these estates.     

Toledo Tomorrow: reading Norman Bel Geddes' vision for the future in a shrinking Midwestern City

This paper examines Norman Bel Geddes’ 1945 Geddes, N. B. 1945. Toledo Tomorrow. Toledo: Toledo Blade. [Google Scholar] Toledo Tomorrow plan, his only proposal for a specific city, and its stamp on the morphology of today's Toledo. The paper surveys retrospectively the changes in the morphology of the city and critically analyzes the impact of the Toledo Tomorrow Plan. Today's Toledo, a shrinking rustbelt city, reflects Geddes' legacy of neglecting the historic core, focusing on highway infrastructure, that has since worked in tandem with the forces of decentralization and suburbanization, and the city's weak relationship with its natural features and larger region.     

Constructing Homeownership Policy: Social Constructions and the Design of the Low-Income Homeownership Policy Objective

This paper offers a new perspective to explain how and why the U.S. federal government pursued a policy agenda that from the early-1990s promoted homeownership as the preferred housing tenure of choice for low-income households. Using policy design theory (Schneider &; Ingram 1997 Schneider, A. L. and Ingram, H. M. 1997. Policy Design for Democracy, Lawrence, KS: University Press of Kansas.  [Google Scholar]), this paper argues that the social constructions of homeownership, low-income households, and the private mortgage industry were instrumental in the development of policies to increase low-income homeownership. The benefits associated with homeownership, based on long-standing norms around success, stability, and the American Dream, justified government interventions to increase access to private mortgage markets for low-income households. This policy stance, however, did nothing to assist households with maintaining homeownership for the long term. The social constructions embedded in the rationales and implementation of these policies contributed to their failure to sustain homeownership and realize its benefits for low-income homeowners.     

Methodology and base cost models to determine the total benefits of preservation interventions on road sections in Switzerland

In Switzerland, it is common practice to estimate the total benefits of new roads before they have been built and of road improvement interventions before they have been performed. The guidelines with respect to standardised methodologies and models to be used have been developed (VSS 2003a VSS. 2003a. SN 641 820: Cost-benefit analysis in road traffic, Switzerland: Swiss Association of Road and Traffic Experts (VSS). Technical Committee 2: Planning and Development (in German) [Google Scholar]) and are now in use. It is not yet, however, common practice to estimate the total benefits of road preservation interventions and hence guidelines do not exist with respect to standardised methodologies and models to be used. In order to provide this information, the research package VSS 2004/710-716 was started. This paper presents the methodology and models proposed to be used to evaluate the total benefits of road preservation interventions in Switzerland based on the evaluation and synthesis of existing national and international literature on the relationships between pavement condition and benefits of road use conducted in project 714 of the research package. The use of the methodology and models are demonstrated by determining the optimal intervention strategy for a representative situation in Switzerland. The impact on the optimal intervention strategy of the consideration of multiple stakeholders is investigated.     

Positioning Lean within an exploration of engineering construction

Engineering construction has specific characteristics that separate it from other types of construction such as technical complexity, onerous safety, health and environmental regulations, duality of new build combined with maintenance and repair, largely owner/user commissioning clients, value propositions revolving around a production Process, etc. The recent Gibson report (Gibson, 2009 Gibson, M. 2009. Changing to Compete: Review of Productivity and Skills in UK Engineering Construction, London: Department for Business, Innovation and Skills.  [Google Scholar]) highlighted several significant problems associated with engineering construction in the UK arising, in many cases, from skill shortages and poor client–contractor relationships. Informal observation and a literature review enable 12 factors to be proposed that differentiate engineering construction from other forms of construction. A new paradigm for the construction sector is Lean construction. This is an adaptation of Lean production and is based on a philosophy that focuses on delivering improved value through the assembly of problem-solving networks of knowledgeable and skilled people. Accepting that Lean construction exists in theory as a method for improving a raft of construction production issues, the question is asked here as to whether it is also relevant to the set of additional factors identified as applying specifically to production in an engineering construction context. The discussion concludes that Lean construction principles can be applied in engineering construction and that an improvement in value could be achieved. Note: throughout this paper the word ‘process’ is used in two contexts—the design and construction process and the end Process that is the function of the client business, e.g. water treatment Process, food manufacturing Process. The context is distinguished by the capitalization of the first letter.     

A new way of developing semantic differential scales with personal construct theory

Measurement is a fundamental issue in management research. However, traditional scale development methods have the drawback of mixing researchers' bias with the scale design. Based on Ding et al.'s (2007 Ding, Z. K., Ng, F. F. and Cai, Q. Y. 2007. Personal constructs affecting interpersonal trust and willingness to share knowledge between architects in project design teams.. Construction Management and Economics, 25: 937–50. [Taylor &; Francis Online] , [Google Scholar]) exploratory work, a new way to develop semantic differential measurement scales is proposed and tested with a survey in the context of the construction industry. The purpose is to provide researchers and practitioners with a new method to develop semantic differential scales for measurement while the bias from their own perspective can be reduced. The reliability and validity of semantic differential scales according to the new method are tested with SPSS and Amos 6.0. The results show that the generated semantic differential scales with this method have high reliability and validity. The new way to develop semantic differential scales offers researchers and practitioners one more choice of scale development. The general application of this new method to other contexts is yet to be tested.