Cost and time control of construction projects: a survey of contractors and consultants in the UK

Numerous techniques have been developed to control cost and time of construction projects. However, there is limited research on issues surrounding the practical usage of these techniques. To address this, a survey was conducted on the top 150 construction companies and 100 construction consultancies in the UK aimed at identifying common project control practices and factors inhibiting effective project control in practice. It found that despite the vast application of control techniques a high proportion of respondents still experienced cost and time overruns on a significant proportion of their projects. Analysis of the survey results concluded that more effort should be geared at the management of the identified top project control inhibiting factors. This paper has outlined some measures for mitigating these inhibiting factors so that the outcome of project time and cost control can be improved in practice.

Risk and benefit assessment for Tolcapone in the treatment of Parkinson's disease

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Achieving low cost and high quality aero structure assembly through integrated digital metrology systems

Measurement assisted assembly (MAA) has the potential to facilitate a step change in assembly efficiency for large structures such as airframes through the reduction of rework, manually intensive processes and expensive monolithic assembly tooling. It is shown how MAA can enable rapid part-to-part assembly, increased use of flexible automation, traceable quality assurance and control, reduced structure weight and improved aerodynamic tolerances. These advances will require the development of automated networks of measurement instruments; model based thermal compensation, the automatic integration of 'live' measurement data into variation simulation and algorithms to generate cutting paths for predictive shimming and drilling processes. This paper sets out an architecture for digital systems which will enable this integrated approach to variation management. © 2013 The Authors.

Comparison of cost- and energy-efficient signal modulations for next generation passive optical networks

Extensive numerical investigations are undertaken to analyze and compare, for the first time, the performance, techno-economy, and power consumption of three-level electrical Duobinary, optical Duobinary, and PAM-4 modulation formats as candidates for high-speed next-generation PONs supporting downstream 40 Gb/s per wavelength signal transmission over standard SMFs in C-band. Optimization of transceiver bandwidths are undertaken to show the feasibility of utilizing low-cost and band-limited components to support next-generation PON transmissions. The effect of electro-absorption modulator chirp is examined for electrical Duobinary and PAM-4. Electrical Duobinary and optical Duobinary are powerefficient schemes for smaller transmission distances of 10 km SMFs and optical Duobinary offers the best receiver sensitivity albeit with a relatively high transceiver cost. PAM-4 shows the best power budget and costefficiency for larger distances of around 20 km, although it consumes more power. Electrical Duobinary shows the best trade-off between performance, cost and power dissipation.

A tranzakciós költségek elmélete és a társadalmi csereelmélet hatásai a bizalomra az ellátási láncban (Affects of Transaction cost and Social Exchange Constructs on trust In supply chain relationship)

A szerzők alapvető feltételezése, hogy az ellátási láncban a bizalom ösztönzi a felek közötti elkötelezettséget. Továbbá a bizalom növeli annak a lehetőségét, hogy az ellátási lánc sikeresen működjön. Ugyanakkor, a felek közötti bizalom hiánya gyakran megnöveli a tranzakciós költségeket, és így csökkenti a hatékonyságot. A cikkben bemutatott kutatás adatgyűjtésére több országban – Franciaországban, Magyarországon, Dél-Koreában, Tunéziában és az Egyesült Államokban – került sor. Összesen 729 érvényes kérdőív érkezett vissza, amelyeket a különböző ellátási láncok résztvevői töltöttek ki. A kutatási eredmények szerint az ellátási láncokon belüli üzleti kapcsolatokban a tranzakciós költségek elméletének összetevői (kapcsolatspecifikusság és viselkedési bizonytalanság), valamint a társadalmi csereelmélet tényezői (lecserélhetőség, észlelt megelégedettség, a partner hírneve és észlelt konfliktus) szoros kapcsolatban állnak a bizalom és az elkötelezettség változóival. _____ This article is based on the assumption that trust promotes commitment between partners in the supply chain and improves the chances of return on supply chain success. In contrast, a lack of trust between them often increases transaction costs and results in inefficiency. The results of this research, based on multi-country surveys with 729 returns from France, Hungary, Korea, Tunisia and the United States on supply chain professionals, reveals a strong affect of transaction cost constructs (TCC) (asset specificity and behavioral uncertainty) and social exchange constructs (SEC) (replaceability, perceived satisfaction, partner reputation, and perceived conflict) on trust-commitment variables in partnership based supply chain relationships. This paper employed a structural equation model to extract information from the survey data. Among the findings, the research indicates that a firm’s trustcommitment in dealing with their supply chain partnership is highly associated with not only transaction cost, but more so with social exchange variables. This study may open a new research avenue in that there is another construct, SEC, beside TSC that influences the degree of trust and commitment.

Költség- és időcsökkentési eljárások alkalmazása a projekttervezésben és a nyomon követésben = Application of cost and time reduction procedures in project planning and the follow-up

A válság okozta megszorítások a projektek költségvetését sem hagyták változatlanul. Nagyon sokszor nemcsak a jövőbeni projekttervek költségvetését kell átgondolni, hanem a már futó projektek költségvetését is újra kell szabni. E tanulmány ilyen esetekben nyújthat módszertani támogatást. A szerző ebben a kutatásban négy költség- és időcsökkentő módszert hasonlít össze. Ismerteti, hogy ezeket az eljárásokat milyen módon lehet ötvözni, illetve mikor, melyiket célszerű alkalmazni. Az eljárások között van olyan módszer, amely a hagyományos projektmenedzsment (pl. építési, beruházási projektek menedzselésének) eszköztárát gazdagítja, de találkozhatunk olyan eljárásokkal is, amelyek az agilis projektszemléleten alapuló módszerek körét szélesítik. A bemutatott módszerek nemcsak a hálótervezési, hanem a mátrixos projekttervezési eljárások esetén is alkalmazhatók. ____ Due to the effects of the crisis, budgets of present as well as future projects are decreasing steadily. In this study four different methods are introduced for minimising budget and time demands. These introduced methods support not only the traditional but also the agile project management. Furthermore these methods can be used not only in case of network planning, but also for matrix-based project planning.

A bizalmat befolyásoló tényezők vizsgálata az üzleti kapcsolatokban (Affects of Transaction cost and Social Exchange Constructs on trust In supply chain relationship)

Az üzleti célú kapcsolatok vizsgálatakor legtöbbször felmerül a bizalom fogalma is, amellyel először a szociálpszichológia és a szociológia foglalkozott. A szerző cikkében azzal foglalkozik, hogy milyen tényezők befolyásolják a bizalmat az üzleti kapcsolatokban. Ezért magyarországi szervezeteket (elsősorban üzleti vállalkozásokat) kérdezett meg kvantitatív módszer alkalmazásával. Ez az empirikus kutatás igyekszik a bizalom lehető legtöbb tényezőit összegyűjteni, ahol a kérdőívben a válaszolók egyik létező – vevői vagy beszállítói – kapcsolatukra gondolva válaszoltak a bizalmon túl a partner hírnevére, az észlelt elégedettségre és konfliktusra, az információcserére, a lecserélhetőségre, valamint a kapcsolatspecifikus beruházásokra vonatkozóan. Az eredmények azt mutatják, hogy egyik változó sem jelent kizárólagos befolyásoló erőt, hanem közösen alakítják ki a bizalom adott szintjét. _______ This article is based on the assumption that trust promotes commitment between partners in the supply chain and improves the chances of return on supply chain success. In contrast, a lack of trust between them often increases transaction costs and results in inefficiency. The results of this research, based on multi-country surveys with 729 returns from France, Hungary, Korea, Tunisia and the United States on supply chain professionals, reveals a strong affect of transaction cost constructs (TCC) (asset specificity and behavioral uncertainty) and social exchange constructs (SEC) (replaceability, perceived satisfaction, partner reputation, and perceived conflict) on trust-commitment variables in partnership based supply chain relationships. This paper employed a structural equation model to extract information from the survey data. Among the findings, the research indicates that a firm’s trustcommitment in dealing with their supply chain partnership is highly associated with not only transaction cost, but more so with social exchange variables. This study may open a new research avenue in that there is another construct, SEC, beside TSC that influences the degree of trust and commitment.

An integrated multi-agent framework for optimizing time, cost and environmental impact of construction processes

Environmentally conscious construction has received a significant amount of research attention during the last decades. Even though construction literature is rich in studies that emphasize the importance of environmental impact during the construction phase, most of the previous studies failed to combine environmental analysis with other project performance criteria in construction. This is mainly because most of the studies have overlooked the multi-objective nature of construction projects. In order to achieve environmentally conscious construction, multi-objectives and their relationships need to be successfully analyzed in the complex construction environment. The complex construction system is composed of changing project conditions that have an impact on the relationship between time, cost and environmental impact (TCEI) of construction operations. Yet, this impact is still unknown by construction professionals. Studying this impact is vital to fulfill multiple project objectives and achieve environmentally conscious construction. This research proposes an analytical framework to analyze the impact of changing project conditions on the relationship of TCEI. This study includes green house gas (GHG) emissions as an environmental impact category. The methodology utilizes multi-agent systems, multi-objective optimization, analytical network process, and system dynamics tools to study the relationships of TCEI and support decision-making under the influence of project conditions. Life cycle assessment (LCA) is applied to the evaluation of environmental impact in terms of GHG. The mixed method approach allowed for the collection and analysis of qualitative and quantitative data. Structured interviews of professionals in the highway construction field were conducted to gain their perspectives in decision-making under the influence of certain project conditions, while the quantitative data were collected from the Florida Department of Transportation (FDOT) for highway resurfacing projects. The data collected were used to test the framework. The framework yielded statistically significant results in simulating project conditions and optimizing TCEI. The results showed that the change in project conditions had a significant impact on the TCEI optimal solutions. The correlation between TCEI suggested that they affected each other positively, but in different strengths. The findings of the study will assist contractors to visualize the impact of their decision on the relationship of TCEI.

Time, Cost, and Environmental Impact Analysis for Sustainable Design at Multiple Building Levels

Construction projects are complex endeavors that require the involvement of different professional disciplines in order to meet various project objectives that are often conflicting. The level of complexity and the multi-objective nature of construction projects lend themselves to collaborative design and construction such as integrated project delivery (IPD), in which relevant disciplines work together during project conception, design and construction. Traditionally, the main objectives of construction projects have been to build in the least amount of time with the lowest cost possible, thus the inherent and well-established relationship between cost and time has been the focus of many studies. The importance of being able to effectively model relationships among multiple objectives in building construction has been emphasized in a wide range of research. In general, the trade-off relationship between time and cost is well understood and there is ample research on the subject. However, despite sustainable building designs, relationships between time and environmental impact, as well as cost and environmental impact, have not been fully investigated. The objectives of this research were mainly to analyze and identify relationships of time, cost, and environmental impact, in terms of CO2 emissions, at different levels of a building: material level, component level, and building level, at the pre-use phase, including manufacturing and construction, and the relationships of life cycle cost and life cycle CO2 emissions at the usage phase. Additionally, this research aimed to develop a robust simulation-based multi-objective decision-support tool, called SimulEICon, which took construction data uncertainty into account, and was capable of incorporating life cycle assessment information to the decision-making process. The findings of this research supported the trade-off relationship between time and cost at different building levels. Moreover, the time and CO2 emissions relationship presented trade-off behavior at the pre-use phase. The results of the relationship between cost and CO2 emissions were interestingly proportional at the pre-use phase. The same pattern continually presented after the construction to the usage phase. Understanding the relationships between those objectives is a key in successfully planning and designing environmentally sustainable construction projects.

Computational Tracking of Mental Health in Youth: Latin American Contributions to a Low-Cost and Effective Solution for Early Psychiatric Diagnosis

The early onset of mental disorders can lead to serious cognitive damage, and timely interventions are needed in order to prevent them. In patients of low socioeconomic status, as is common in Latin America, it can be hard to identify children at risk. Here, we briefly introduce the problem by reviewing the scarce epidemiological data from Latin America regarding the onset of mental disorders, and discussing the difficulties associated with early diagnosis. Then we present computational psychiatry, a new field to which we and other Latin American researchers have contributed methods particularly relevant for the quantitative investigation of psychopathologies manifested during childhood. We focus on new technologies that help to identify mental disease and provide prodromal evaluation, so as to promote early differential diagnosis and intervention. To conclude, we discuss the application of these methods to clinical and educational practice. A comprehensive and quantitative characterization of verbal behavior in children, from hospitals and laboratories to homes and schools, may lead to more effective pedagogical and medical intervention

Clinical characteristics and benefit of cataract intervention amongst UK domiciliary eye care recipients

Purpose: Given the ageing UK population and the high prevalence of activity-limiting illness and disability in the over 65s, the demand for domiciliary eye care services is set to grow significantly. Over 400,000 NHS domiciliary eye examinations are conducted each year, yet minimal research attention has been directed to this mode of practice or patient needs amongst this group. The study aimed to compare clinical characteristics and benefits of cataract surgery between conventional in-practice patients and domiciliary service users. Methods: Clinical characteristics were compared between patients in North-West England receiving NHS domiciliary eye care services (n = 197; median age 76.5 years), and an age-matched group of conventional in-practice patients (n = 107; median age 74.6 years). Data including reason for visit; logMAR uncorrected and best corrected distance (UDVA and CDVA) and near acuities (UNVA and CNVA); presence of ocular pathology and examination outcome were documented retrospectively. To compare the benefit of cataract surgery in terms of functional capacity between the patient groups, individuals undergoing routine referral for first-eye surgery completed the VF-14 questionnaire pre-operatively, and at 6 weeks post-operatively. Results: UDVA was similar between the two groups (median 0.48 and 0.50 logMAR in the domiciliary and practice groups, P = 0.916); CDVA was significantly worse in the domiciliary group (median 0.18 vs 0.08 logMAR, P<0.001), who were more likely to have clinically-significant cataract. Both groups showed similar improvements in VF-14 scores following cataract surgery (mean gains 24.4 ± 11.7, and 31.5 ± 14.7 points in the in-practice and domiciliary groups, respectively. P = 0.312). Conclusions: Patients receiving domiciliary eye care services are more likely to have poorer corrected vision than in-practice patients of a similar age, partly due to a higher prevalence of significant cataract. Despite limitations in their activities due to illness and disability, domiciliary patients experience similar gains in self-reported functional capacity following cataract surgery

Management of public water supply to reduce power cost and improve wind power uptake

This paper presents a study on the implementation of Real-Time Pricing (RTP) based Demand Side Management (DSM) of water pumping at a clean water pumping station in Northern Ireland, with the intention of minimising electricity costs and maximising the usage of electricity from wind generation. A Genetic Algorithm (GA) was used to create pumping schedules based on system constraints and electricity tariff scenarios. Implementation of this method would allow the water network operator to make significant savings on electricity costs while also helping to mitigate the variability of wind generation.

Management of public water supply to reduce energy cost and improve wind power uptake

This paper presents a study on the implementation of Real-Time Pricing (RTP) based Demand Side Management (DSM) of water pumping at a clean water pumping station in Northern Ireland, with the intention of minimising electricity costs and maximising the usage of electricity from wind generation. A Genetic Algorithm (GA) was used to create pumping schedules based on system constraints and electricity tariff scenarios. Implementation of this method would allow the water network operator to make significant savings on electricity costs while also helping to mitigate the variability of wind generation.

Management of public water supply to reduce energy cost and improve wind power uptake

This paper presents a study on the implementation of Real-Time Pricing (RTP) based Demand Side Management (DSM) of water pumping at a clean water pumping station in Northern Ireland, with the intention of minimising electricity costs and maximising the usage of electricity from wind generation. A Genetic Algorithm (GA) was used to create pumping schedules based on system constraints and electricity tariff scenarios. Implementation of this method would allow the water network operator to make significant savings on electricity costs while also helping to mitigate the variability of wind generation.