scholarly journals Cost Escalation in Road Construction Contracts

2021 ◽  
pp. 036119812110054
Author(s):  
Morten Welde ◽  
Roy Endre Dahl
Keyword(s):  
Project Success ◽  
Road Construction ◽  
Unit Price ◽  
Future Research ◽  
Cost Overrun ◽  
Project Cost ◽  
Important Indicator ◽  
Construction Contracts ◽  
Contract Costs ◽  
Original Contract

This paper presents a study of cost escalation in unit price road construction contracts. The aim is to investigate why the final cost of contracts differs from the agreed contract cost following tendering, both to identify causes of observed discrepancies and to suggest measures that could improve the planning and delivery of future projects. Road projects often consist of several contracts and as they account for the biggest costs of the projects, cost escalation in the contracts may increase the risk of project cost overrun. Even if contract cost performance is an important indicator of project success, it may be too simplistic to equate this with project success. It is quite possible to deliver a project within budget even if contract costs escalate, as long as the project cost contingency is adequate to cover such escalations. However, escalations in contracts increase the risk of project overrun and may lead to other problems such as conflicts and delays. The results show that most of the studied contracts experienced cost escalation. The main cause of the escalation was change orders to the scope that were not covered by the original contract. In addition, the results indicate that complexity represented by contract size, duration, and urban location increases the risk and size of cost overrun. Based on these findings, the paper presents some recommendations on how contract delivery can be improved as well as some implications for future research.

A Review of Drug Side Effect Identification Methods

2020 ◽  
Vol 26 (26) ◽  
pp. 3096-3104 ◽  
Author(s):  
Shuai Deng ◽  
Yige Sun ◽  
Tianyi Zhao ◽  
Yang Hu ◽  
Tianyi Zang
Keyword(s):  
Side Effects ◽  
Future Research ◽  
Drug Side Effects ◽  
Important Indicator ◽  
Advantages And Disadvantages ◽  
Key Points ◽  
Network Methods ◽  
Future Research Directions ◽  
The One ◽  
Approved Drugs

Drug side effects have become an important indicator for evaluating the safety of drugs. There are two main factors in the frequent occurrence of drug safety problems; on the one hand, the clinical understanding of drug side effects is insufficient, leading to frequent adverse drug reactions, while on the other hand, due to the long-term period and complexity of clinical trials, side effects of approved drugs on the market cannot be reported in a timely manner. Therefore, many researchers have focused on developing methods to identify drug side effects. In this review, we summarize the methods of identifying drug side effects and common databases in this field. We classified methods of identifying side effects into four categories: biological experimental, machine learning, text mining and network methods. We point out the key points of each kind of method. In addition, we also explain the advantages and disadvantages of each method. Finally, we propose future research directions.

scholarly journals Influential Factors and Evaluation Methods of the Performance of Grouted Semi-Flexible Pavement (GSP)—A Review

2021 ◽  
Vol 11 (15) ◽  
pp. 6700
Author(s):  
Xiaogang Guo ◽  
Peiwen Hao
Keyword(s):  
Literature Review ◽  
Systematic Literature Review ◽  
Asphalt Concrete ◽  
Cement Mortar ◽  
Road Construction ◽  
Flexible Pavement ◽  
Evaluation Methods ◽  
Influential Factors ◽  
Future Research ◽  
Relative Evaluation

Grouted Semi-flexible Pavement (GSP) is a novel pavement composed of open-graded asphalt concrete grouted with high-fluidity cement mortar. Due to its excellent load-bearing and anti-rutting performance, it has great potential as anti-rutting overlay and surface in road construction. However, the understanding of GSP performance remains limited and pertinent findings are inconsistent. This article aims to provide a systematic literature review for the articles which were published between 2000 and 2020 on GSP, explore the problems in the recent research, identify knowledge gaps, and deliver recommendations for future research. The influential factors and the relative evaluation methods of GSP performance are summarized and discussed in this article.

scholarly journals Discrepancies between Global Forest Net Primary Productivity Estimates Derived from MODIS and Forest Inventory Data and Underlying Factors

2021 ◽  
Vol 13 (8) ◽  
pp. 1441
Author(s):  
Jin Han Park ◽  
Jianbang Gan ◽  
Chan Park
Keyword(s):  
Low Income ◽  
Primary Productivity ◽  
Carbon Stock ◽  
Forest Cover ◽  
Net Primary Productivity ◽  
Estimation Methods ◽  
Future Research ◽  
Important Indicator ◽  
Sequestration Potential ◽  
Carbon Losses

The net primary productivity (NPP) of a forest is an important indicator of its potential for the provision of ecosystem services such as timber, carbon, and biodiversity. However, accurately and consistently quantifying global forest NPP remains a challenge in practice. We converted carbon stock changes using the Global Forest Resources Assessment (FRA) data and carbon losses associated with disturbances and timber removals into an NPP equivalent measurement (FRA NPP*) and compared it with the NPP derived from the MODIS satellite data (MOD17 NPP) for the world’s forests. We found statistically significant differences between the two NPP estimates, with the FRA NPP* being lower than the MOD17 NPP; the differences were correlated with forest cover, normalized difference vegetation index (NDVI), and GDP per capita in countries, and may also stem from the NPP estimation methods and scopes. While the former explicitly accounts for carbon losses associated with timber removals and disturbances, the latter better reflects the principles of photosynthesis. The discrepancies between the two NPP estimates increase in countries with a low income or low forest cover, calling for enhancing their forest resource assessment capacity. By identifying the discrepancies and underlying factors, we also provide new insights into the relationships between the MOD17 NPP and global forest carbon stock estimates, motivating and guiding future research to improve the robustness of quantifying global forest NPP and carbon sequestration potential.

Research on the Impact of Temperature on the Softening Point of SBS Modified Asphalt

2013 ◽  
Vol 365-366 ◽  
pp. 978-982
Author(s):  
Xiao Wei Feng ◽  
De Wen Zhang
Keyword(s):  
Softening Point ◽  
Heating Temperature ◽  
Road Construction ◽  
Curing Temperature ◽  
Important Indicator ◽  
Modified Asphalt ◽  
Influence Of Temperature On ◽  
Sbs Modified Asphalt ◽  
The Impact ◽  
Initial Heating

The softening point of modified asphalt is an extremely important indicator to evaluate the high-temperature performance; its the temperature of modified asphalt sample emerging shear deformation under the action of certain shear stress according to the specific heating rate. Its found that in the actual construction and testing, different temperature conditions has a larger impact on the softening point of the modified asphalt, which has adverse affect on road construction. This paper studied and researched the influence of temperature on modified asphalt softening point indicators from the different test temperature, including packing compact temperature, scraper temperature in removal of asphalt that above test mode, standing temperature, curing temperature and initial heating temperature before test.

scholarly journals Delay and cost overrun in road construction projects in Jordan

2015 ◽  
Vol 4 (2) ◽  
pp. 288 ◽  
Author(s):  
Nabil Al-Hazim ◽  
Zaydoun Abusalem
Keyword(s):  
Construction Projects ◽  
Road Construction ◽  
Weather Conditions ◽  
Public Works ◽  
Fiscal Year ◽  
Cost Overrun ◽  
Construction Time ◽  
Change Orders ◽  
Critical Problems ◽  
The Cost

This study aims to identify the most important factors that cause delay in road construction projects in Jordan, which results in cost and time overrun allocated for this type of engineering projects and cause critical problems for both the developer and the contractor. The gap between the cost at completion and that originally estimated, known as cost overrun, can be regarded as one of the most important parameters reflecting the success of projects. In the public sector, money spent on project change orders results in increased construction time which in return reduces the number and size of the projects that can be completed during any given fiscal year. To achieve this goal, the documents and the final reports for several sample projects implemented over the years 2000 to 2008 were analyzed. All the projects were administered by the same organization taken from Jordan Ministry of Rural and Public Works. The results of this study can assist highway officials in their design, planning, scheduling and projects completions so that necessary actions can be taken to control these overruns in future projects. The study showed that 19 factors might cause delays of road construction projects as defined through a detailed literature review. The analysis of the study indicated that the top causes affecting time and cost overrun in road construction projects in Jordan are Terrain and Weather conditions.

scholarly journals Analysis of Time Delay and Cost Overrun in Road Construction

2019 ◽  
Vol 8 (9S3) ◽  
pp. 901-907
Keyword(s):  
Economic Development ◽  
Time Delay ◽  
Construction Industry ◽  
Road Construction ◽  
Cost Overrun

Road construction is the important division in the construction industry and the most predominant part of a society. The roadway defines the development of a country or a state and brings in the economic development of the same. The reasons for choosing a project on the roadways are its vast scope of day to day development and progress in this area. Thus it is clearly seen that roadways is the most essential in todays world without which progress and development cannot take place at full fledge. Therefore any delay in completion of a road constructing project may have its impact in degrading of a society. Also at the same time the budget overrun or cost overrun of such project is highly unbearable.

scholarly journals Characterization of the skin microbiota in bullous pemphigoid patients and controls reveals novel microbial indicators of disease

2021 ◽  
Author(s):  
Meriem Belheouane ◽  
Britt M Hermes ◽  
Nina Van Beek ◽  
Sandrine Benoit ◽  
Philippe Bernard ◽  
...  
Keyword(s):  
Bullous Pemphigoid ◽  
Disease Risk ◽  
Disease Status ◽  
The Elderly ◽  
Future Research ◽  
Sampling Effort ◽  
Skin Microbiota ◽  
Important Indicator ◽  
Blistering Disease ◽  
Microbe Interactions

Bullous pemphigoid (BP) is an autoimmune skin blistering disease afflicting mostly the elderly and is associated with significantly increased mortality. Here, we conducted the most extensive sampling effort of skin microbiota in BP to date to analyze whether intra-individual, body-site-specific, and/or geographical variation contributes to the emergence of BP. We find marked differences in the skin microbiota of BP patients compared to that of control subjects, and moreover that disease status rather than skin biogeography governs the skin microbiota composition in BP. Our data reveal a discernible transitional stage between normal and diseased skin in BP characterized by a loss of protective microbiota and an increase in sequences matching Staphylococcus aureus, a known inflammation-promoting species. Notably, S. aureus is ubiquitously associated with disease status, suggesting that this taxon is an important indicator of BP. Importantly, differences in a few key indicator taxa are able to reliably discriminate between BP patients and controls, characterized by their opposing abundance patterns. This may serve as valuable information for assessing disease risk and treatment outcomes. Future research will focus on the functional analysis of host-microbe and microbe-microbe interactions and the relevance of the host genome for microbiota abundances to identify novel BP treatment approaches.

scholarly journals A BESPOKE APPROACH FOR RELATING MATERIAL WASTE TO COST OVERRUN IN THE CONSTRUCTION INDUSTRY

2017 ◽  
Vol 1 (1) ◽  
pp. 39-52
Author(s):  
Ibrahim Saidu ◽  
W Shakantu ◽  
A Adamu ◽  
I Anugwo
Keyword(s):  
Construction Industry ◽  
Construction Material ◽  
Methodological Approach ◽  
Construction Project ◽  
Project Managers ◽  
Cost Overrun ◽  
Project Cost ◽  
Cost Overruns ◽  
Project Completion ◽  
Final Project

The problems of material waste and cost overruns are common in the construction industry. These problems occur at different stages of a construction project, from planning, design to project completion. The argument on how to eliminate cost overrun has been on-going for the past 70 years as on-site wastage of materials leads to increase in the final project cost. This paper examines the relationship between the causes of material waste and those of cost overrun at the pre-contract and post-contract stages of a project. The desktop methodological approach was firstly adopted in comparing the causes of material waste and those of cost overruns from the literature, in order to determine the possible relationship. Subsequently, interviews were purposively conducted with construction professionals within Abuja, Nigeria, in order to verify the literature based information. The result reveals that all the causes of material waste also cause cost overrun at the pre-contract and the post-contract stages of a project. 96.88% and 81.81% of the causes of cost overrun also cause material waste at the pre-contract and post-contract stages respectively. Other causes which are not related are mostly, the micro-economic and macro-economic factors. These results are not different from those of the interviews conducted with professionals and summarised in the tick box. It was also found that to achieve Effective Construction Material Waste Management (ECMWM) for any construction project, material waste must be controlled at its sources and causes, and at different stages of a project. Based on these findings, it can be concluded that effective management of material waste would translate into a reduction in the level of project cost overrun. The study recommends that construction-project managers, as well as the construction practitioners should encourage the management of material-waste causes, as it has the potential to minimise cost overrun for projects. 

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