1,721,301 research outputs found
Chapter 15 - Keeping it Simple? A case study into the Advantages and disadvantages of reducing complexity in mega project planning
No full textGoverning Large Projects: A Three-Stage Process to Get It Right
No full textPrivate and public megaprojects, whether new plant facilities, IT systems, skyscrapers, airports, railways, roads, or the Olympics, are frequently associated with dramatic cost and schedule overruns. The root causes are behavioral biases – such as optimism and deliberate deception – accompanied by principal-agent issues and a lack of project-related skills. Through a three-stage process – i.e., Forecasting, Organizing, and Executing (FOX) – we organize and offer solutions to mitigate the cognitive biases and agency issues planners and policymakers face in large projects. Following the three-stage FOX process and building on Behavioral Decision Theory (BDT), we first review evidence for the accuracy of Reference Class Forecasting (RCF), which considers comparable past projects to forecast a current, planned project. We provide evidence for RCF performance and recent methodological extensions such as Similarity Based Forecasting (SBF). Second, considering the principal-agent and project governance literature, we offer organizational solutions to reduce unfounded optimism and deception, including debiasing techniques and specific measures to curb principal-agent issues. Third, we suggest combining a project modular design with speedy implementation for faster, better, cheaper, and lower-risk execution. Overall, we offer an original, holistic theoretical view that deals with both behavioral and strategic elements of how to debias large projects, along with direct practical implications and advice for those who manage megaprojects with increasingly high stakes and risks
Cost Overruns in Large-Scale Transport Infrastructure Projects: A theoretical and empirical exploration for the Netherlands and worldwide
No full textIn the Netherlands, the costs of railroad infrastructure construction work out 11 per cent higher than forecast; the percentage for roads is 19 and 22 for bridges and tunnels. While this puts the Netherlands in a favourable light compared to other countries, the actual cost overruns are probably far higher, believes Chantal Cantarelli, who obtained her doctorate on this subject from TU Delft on Monday, 28 November. International research into cost overruns among 258 large-scale transport infrastructure projects has shown that roads generally turn out to be 20 per cent more expensive, bridges and tunnels 34 per cent and railroads 45 per cent. ‘But what about the Netherlands?’, TU Delft PhD student Chantal Cantarelli asked herself. From her study of the situation in the Netherlands, it appeared that the costs were higher than predicted in more than half the projects involving roads, bridges, tunnels and railroads. Cost overruns occur less frequently than abroad and they are also smaller in extent. Railroads usually turn out 11 per cent more expensive, roads 19 per cent and bridges and tunnels 22 per cent. Worldwide, however, the cost overruns involved in constructing railroads are higher than in the case of roads. Another notable fact is that the greatest cost increases take place in the phase prior to construction and not during construction itself. However, it would be a mistake to conclude that cost overruns aren't that much of a problem in the Netherlands, warns Cantarelli. Overruns are, she points out, often based on a comparison between the costs upon final delivery and the costs estimated at the time the formal decision was taken. But politicians have often made an informal decision at a much earlier stage. This phenomenon is known as lock-in. The estimates at the time of the unofficial decision are often much lower. Cantarelli examined this effect in relation to two Dutch projects, the Betuweroute (a 160 km long double-track railway from the port of Rotterdam to the German border) and the HSL-Zuid (a 125 km long high speed rail line between the Netherlands and the Belgian border). It transpired that politicians had in fact committed themselves to the project four years prior to the moment the formal decision was taken. If one calculates the cost overruns on the basis of the underestimated costs at the time of the informal decision, the costs for the Betuweroute and HSL-Zuid work out as three to four times higher. Cost overruns are therefore presumably far higher than is actually known. According to Cantarelli, it is a matter for concern that cost estimates have not improved in the last twenty years. As estimation methods have certainly improved, there have to be other reasons for systematic overruns. Cantarelli concludes that to improve cost forecasts, another cost methodology should be applied in addition. The method Reference Class Forecasting is particularly suitable for this purpose. On the basis of this methodology, estimates are calculated by comparing the actual costs and cost overruns of similar realised projects. This helps to avoid overly optimistic estimates. But strategic behaviour on the part of parties, in the form of deliberately estimating lower costs, may also play a role. The rules of play should change in order to make it harder for interested parties to exhibit such behaviour. In this regard, it is also important that responsibility for future cost overruns should be borne by those drawing up the estimates.Infrastructure Systems & ServicesTechnology, Policy and Managemen
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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