CAUSES OF VARIATION ORDERS FOR MEGA CONSTRUCTION PROJECTS

2016 ◽  
Vol 3 (2) ◽  
Author(s):  
Samer Ezeldin ◽  
Amr Khaled El-Sadek
Keyword(s):  
United Kingdom ◽  
Construction Projects ◽  
Construction Project ◽  
Project Schedule ◽  
Mena Region ◽  
Project Cost ◽  
Change Orders ◽  
The United Kingdom

Variations or change orders are inevitable in any construction project. They are defined as any change that happens in the scope of the project. Change is an additional scope of work, omission, or even alteration. This paper presents the main causes of variation orders in MENA region represented by Egypt. The research investigates the causes, as identified by clients, consultants, and contractors. It classifies them into four main categories: owner related, contractor related, consultant related, and other causes. The top 10 most important causes are ranked among the opinion of each party. The study reveals that the top 3 causes are: 1) The client instruction of additional works; 2) The contractor using ambiguous areas in the contract to request variations, and 3) continuous changes in the project schedule. A comparison about causes of variations was performed between Egypt, Palestine, Malaysia, and the United Kingdom. Furthermore, a model is proposed to provide the user with a scale that predicts the effect of the events triggering variations on both project cost and time.

scholarly journals Scheduling Optimization of Prefabricated Construction Projects by Genetic Algorithm

2021 ◽  
Vol 11 (12) ◽  
pp. 5531
Author(s):  
Linlin Xie ◽  
Yajiao Chen ◽  
Ruidong Chang
Keyword(s):  
Project Scheduling ◽  
Construction Projects ◽  
Resource Constraints ◽  
Construction Project ◽  
Engineering Application ◽  
Project Schedule ◽  
Scheduling Optimization ◽  
Implementation Method ◽  
Traditional Construction ◽  
Construction Project Scheduling

Prefabricated buildings are the direction of the future development of the construction industry and have received widespread attention. The effective execution of prefabricated construction project scheduling should consider resource constraints and the supply arrangement of prefabricated components. However, the traditional construction resource-constrained project scheduling implementation method cannot simultaneously consider the characteristics of the linkage between component production and on-site assembly construction. It cannot also fully adapt to the scheduling implementation method of the prefabricated construction projects. It is difficult to work out a reasonable project schedule and resource allocation table. In order to determine the relevant schedule parameters that can reflect the actual construction situation of the prefabricated building and meet the scheduling requirements of the prefabricated project, this study proposes a prefabricated construction project scheduling model that considers project resource constraints and prefabricated component supply constraints. Additionally, it improves the design of traditional genetic algorithms (GAs). Research results of the experimental calculation and engineering application show that the proposed project scheduling optimization model and GA are effective and practical, which can help project managers in effectively formulating prefabricated construction project scheduling plans, reasonably allocating resources, reducing completion time, and improving project performance.

Regular papers / Articles ordinairesReceiver operating characteristic (ROC) curve analysis of the effectiveness of construction planning efforts in Australia and the United Kingdom

2003 ◽  
Vol 30 (1) ◽  
pp. 159-167 ◽  
Author(s):  
O O Faniran ◽  
D G Proverbs
Keyword(s):  
United Kingdom ◽  
Roc Curve ◽  
Construction Projects ◽  
Operating Characteristic ◽  
Curve Analysis ◽  
Construction Planning ◽  
Roc Curve Analysis ◽  
Building Projects ◽  
The United Kingdom ◽  
Planning Project

This paper presents the results of a receiver operating characteristic (ROC) curve analysis of the effectiveness of construction planning efforts, based on samples of building projects in Australia and the United Kingdom. The results of the study provide an evaluation of the extent of the effort that must be invested in planning and control activities to achieve success in the performance of construction projects. The study also illustrates the potential application of ROC curve analysis in construction engineering and management research. Planning efforts in a sample of 52 building projects in Australia and 37 building projects in the United Kingdom were evaluated and compared. This study builds on work done in an earlier study in which the concept of optimal planning of construction projects was explored. The ROC curve analysis offers several advantages over the regression methodology employed in the previous optimal planning study. The graphical representation of the relationship between sensitivity and specificity over all possible diagnostic cutoff points provides an insight into the interactions of the variables that was not apparent in the original methodology.Key words: construction planning, project planning, project management, ROC curve analysis, Australia, United Kingdom.

scholarly journals Toward Reducing Construction Project Delivery Time under Limited Resources

2021 ◽  
Vol 13 (19) ◽  
pp. 11035
Author(s):  
Hossam H. Mohamed ◽  
Ahmed H. Ibrahim ◽  
Asmaa A. Soliman
Keyword(s):  
Construction Projects ◽  
Resource Constraints ◽  
Optimization Problems ◽  
Cost Optimization ◽  
Construction Project ◽  
Limited Resource ◽  
Project Managers ◽  
Project Schedule ◽  
Java Program ◽  
Optimizing Model

One of the most vital construction project aspects is to complete a project in minimum time restricted to the time–cost trade-off. Overlapping activities’ planning and their impact on the project under limited resource constraints should be considered. This study aims to develop a model for optimizing the project schedule and cost regarding overlap activities and their impacts. This study reviews previous studies on changes in past activities likely to produce additional reworking of subsequent activities. In addition, an AHP model is developed to assess the reworking time of subsequent activities based on possible changes in previous activities. In addition, five realistic construction projects are applied. Finally, an optimizing model is developed for optimizing project time and cost using overlapping techniques by using the Java program. The results indicate that the proposed model can be used by project managers easily for solving time and cost optimization problems. In addition, it can be updated to continuously improve its functionality. Finally, it can be updated later to support AI for finding better solutions.

scholarly journals SCIENTOMETRIC REVIEW OF CONSTRUCTION PROJECT SCHEDULE STUDIES: TRENDS, GAPS AND POTENTIAL RESEARCH AREAS

2020 ◽  
Vol 26 (4) ◽  
pp. 343-363
Author(s):  
Gebrehana Derbe ◽  
Yashuai Li ◽  
Di Wu ◽  
Qiuhong Zhao
Keyword(s):  
Performance Management ◽  
Construction Projects ◽  
Construction Project ◽  
Future Research ◽  
Scientometric Analysis ◽  
Project Schedule ◽  
Document Type ◽  
Research Areas ◽  
Future Potential ◽  
Abstract Content

Scheduling plays a fundamental role in construction projects’ success and thus has drawn attention from both academic researchers and industry practitioners. A large number of research articles tend to solve emerging challenges in construction project schedule (CPS). Therefore, there is a strong need of systematic review on existing studies. In this study, a total of 332 articles were retrieved from Scopus database using title, abstract and keywords with respect to CPS and filtered by document type, language type and abstract content. In particular, science mapping approach was adopted to analyse selected journal articles. These articles were examined using three sequential processes, including bibliometric search, scientometric analysis, and in-depth qualitative discussion. It could demonstrate the most influential journals, researchers, published articles, and active countries/regions in this area. In addition, major CPS knowledge areas were identified and summarized as CPS constructability, applications of variety of CPS methods, CPS optimization models and algorithms, identification and quantification of schedule risks and uncertainties, CPS performance management, and adopting new emerging CPS technologies and methods. Furthermore, knowledge gaps and future potential research directions were also discussed in detail. Finally, a comprehensive CPS framework was proposed as a sound reference in future research.

scholarly journals Upscaling non-residential bio-based circular construction in the United Kingdom

2021 ◽  
Vol 855 (1) ◽  
pp. 012015
Author(s):  
B Dams ◽  
D Maskell ◽  
A Shea ◽  
S Allen ◽  
V Cascione ◽  
...  
Keyword(s):  
United Kingdom ◽  
Case Studies ◽  
Construction Projects ◽  
Large Scale ◽  
The United Kingdom ◽  
Distribution Centre ◽  
Vested Interests ◽  
The Uk ◽  
The University

Abstract Non-residential circular construction projects using bio-based materials have been realised in the United Kingdom. Case studies include the Adnams Distribution Centre, the University of East Anglia’s Enterprise Centre and the British Science Museum’s hempcrete storage facility. The bio-based buildings utilise the natural properties of bio-based materials to insulate and regulate internal environments, particularly with reducing fluctuations in temperature and relative humidity, which can be harmful to sensitive stored products and artefacts. Projects have been successful on both on environmental and physical performance levels; however, they have not led to a subsequent proliferation of non-residential large-scale circular projects within the UK using emerging bio-based materials. This study examines why and uses analysis based upon exclusive interviews with key figures associated with bio-based case studies. Challenges faced include the ability to upscale production by manufacturers of bio-based materials, problems surrounding initial costs, gaining accreditation for materials, the vested interests present in the construction industry and levels of knowledge among clients and construction professionals. Potential upscaling solutions identified include long-term financial savings on running costs and high staff productivity, policies regarding grants, incentives and planning applications and local economic regeneration.

scholarly journals Using meta-networks to analyse the impact of adverse random events on the time and cost of completing

2019 ◽  
Vol 28 (2) ◽  
pp. 192-202
Author(s):  
Grzegorz Śladowski
Keyword(s):  
Construction Projects ◽  
Construction Project ◽  
Dynamic Network ◽  
Single Mode ◽  
Project Schedule ◽  
Material Resources ◽  
Simulation Based ◽  
Random Events ◽  
Risk Sources ◽  
The Impact

According to the concept of a system-based approach, a construction project can be treated as a complex system composed of various elements, such as human, equipment and material resources, as well as knowledge and tasks that are mutually interlinked. In the classical approach to construction project risk assessment, the impact of the “system” in the analysis of relationships between risk sources and their consequences has so far been neglected. The concept of construction project vulnerability and its adaptability has appeared in literature in recent years. It is analysed on the basis of a project’s vulnerability to the impact of risk factors and its adaptive capacity is seen an answer to project perturbations caused by adverse random events. As a part of developing the system-based approach to analysing construction project schedule, the author further developed the concept of modelling planned construction projects with relationship meta-networks composed of four types of nodes: agents (human resources), knowledge, equipment and material resources and tasks. The author included possible deviations from the planned project’s budget in the schedule vulnerability and adaptability analysis, instead of only focusing on deviations from its completion deadline. An analysis of the occurrence of additional and replacement work was introduced by the author, which further developed the concept of the simulated evolution of such networks to include the capacity to introduce new nodes and links into their structure. Furthermore, the author used the potential of weighted meta-networks to model certain dependencies within the planned project. A simulation-based approach as a part of DNA (dynamic network analysis) was used to analyse the vulnerability and adaptability of such networks. The proposed approach was presented on the example of a renovation project performed on a historical structure. The conclusions drawn from the author’s analyses can be used to formulate construction project schedules that are less vulnerable to perturbations and are characterised by greater adaptability. In the future, the author plans to expand the analysis presented above to include dependencies in single-mode networks (e.g. in agent, resource or knowledge networks) on the meta-network of a project.

scholarly journals IDENTIFIKASI RISIKO CHANGE ORDER PROYEK KONSTRUKSI JALAN

2021 ◽  
Vol 5 (1) ◽  
pp. 225
Author(s):  
Mega Waty ◽  
Hendrik Sulistio
Keyword(s):  
Construction Projects ◽  
Construction Project ◽  
Road Construction ◽  
Real Data ◽  
Intermediate Frequency ◽  
Risk Identification ◽  
Construction Work ◽  
Change Orders ◽  
Change Order ◽  
The Cost

A Change Order is a written and legal work order that changes the scope of the original contract, with compensation that has been agreed upon by the owner and the contractor. Changes can be in the form of adding or reducing the scope of work, changing materials, or changing schedules. Change Order causes the cost of contract items to swell, planning errors and negligence as well as changes in scope that can be reduced by sharpening planning results. The scope of research on road construction in Indonesia, especially in DKI Jakarta and Banten provinces. This study aims to determine the identification of change orders in road construction projects. Data obtained from real data on road construction projects from 2013-2018 on 16 road construction project packages in the form of road construction project addendum contracts. Based on the addendum contract, added work, less work, addition of new items and removal of work items are determined. The identification of change order risk is seen from three aspects, namely the addition and reduction of work items, the removal of items and the addition of new items and the wishes of the owner, thereby increasing the cost of the change order contract. This study found 732 changes in construction work items. Risk identification is obtained from the frequency of changes above 35% which is an intermediate frequency that tends to increase the occurrence of change orders. The results of risk identification were obtained for 31 construction work items, the highest percentage was for Thermoplastic Road Marking work, followed by 30 other construction work items. Keywords: risk identification; change orders; road construction projects  AbstrakChange Order adalah perintah kerja tertulis dan sah  yang mengubah lingkup kontrak semula, dengan kompensasi  yang sudah disetujui oleh pemilik dan  kontraktor.  Perubahan dapat berupa penambahan atau pengurangan lingkup pekerjaan, perubahan material, atau perubahan jadwal. Change Order menyebabkan biaya  item kontrak membengkak, kesalahan perencanaan dan kelalaian serta perubahan ruang lingkup yang dapat dikurangi dengan mempertajam hasil perencanaan.. Lingkup penelitian pada konstruksi jalan di Indonesia khususnya  provinsi DKI Jakarta dan Banten. Penelitian  bertujuan untuk  mengetahui  identifikasi change order proyek konstruksi jalan. Data didapat dari data riil proyek konstruksi jalan dari tahun 2013- 2018 pada 16 paket proyek konstruksi jalan berupa kontrak addendum proyek konstruksi jalan. Berdasarkan kontrak addendum maka ditentukan pekerjaan tambah, pekerjaan kurang, penambahan item baru dan penghilangan item pekerjaan. Identifikasi risiko change order dilihat dari tiga aspek yakni penambahan dan pengurangan item pekerjaan, penghilangan item dan penambahan item baru dan keinginan dari pihak owner sehingga meningkatkan biaya kontrak change order.  Penelitian ini mendapatkan 732 perubahan  item pekerjaan konstruksi.  Identifikasi risiko didapat dari  frekuensi perubahan diatas 35% yang merupakan frekuensi menengah yang cenderung meningkatkan terjadinya change order. Hasil identifikasi risiko didapat pada  31 item pekerjaan konstruksi, yang tertinggi persentase pada pekerjaan  Marka Jalan Termoplastik, diikuti 30 item pekerjaan konstruksi lainnya.

scholarly journals Beta Distribution for Estimating Risk Associated Time Schedule of Hydropower Projects in Nepal

2021 ◽  
pp. 67-78
Author(s):  
Kiran Kumar Shrestha ◽  
Rabindra Kayastha
Keyword(s):  
Quantitative Analysis ◽  
Construction Projects ◽  
Construction Project ◽  
Simulation Method ◽  
Development Project ◽  
Project Work ◽  
Time Schedule ◽  
Project Schedule ◽  
Expected Time ◽  
Hydropower Construction

Background: Risk is associated with every kind of project work whether it is related to engineering construction project, software development project, financial transaction process or business process. There isn't any project which is free of risks. It is inherent in all types of projects. Observing risk associated with a project can help in successful completion of projects in expected time and expected cost with good assurance of quality. This article is concerned with quantitative analysis of risks coined with hydropower construction project in Nepal. Objective: The main objective of this paper is (a) to identify different activities involved in hydropower construction projects (b) to estimate risk associated time schedule of the identified project activities. Materials and Methods: Data required for the fulfillment of the objective are obtained by interview and discussion with executives of “Shiva Shree Hydropower Limited” and by using project schedule charts of projects won by the company. In this article quantitative analysis of schedule risk of hydropower project is studied by simulation method. Results: Different activities involved in hydropower construction project are identified. Also, risk associated with time schedule of project are observed quantitatively by simulation using beta-PERT distribution. Conclusion: Estimation of time schedule associated with project activities is more realistic when it is analyzed by using beta-PERT distribution compared to other statistical distributions.

scholarly journals Bayesian Structural Equation Modeling for Examining the Relationship between Multidimensional Factors and Construction Project Cost

2019 ◽  
Author(s):  
Linlin Zhao ◽  
Zhansheng Liu ◽  
Jasper Mbachu
Keyword(s):  
Influencing Factors ◽  
Latent Variables ◽  
Construction Projects ◽  
Construction Project ◽  
Dynamic Environment ◽  
Financial Strain ◽  
Equation Modeling ◽  
Analysis Tool ◽  
Project Cost ◽  
The Relationship

Construction projects are usually operating in a complex and dynamic environment in which the accumulation of many interrelated factors causes high uncertainty. Construction projects are complex and frequently involve substantial uncertainties including process complicatedness, intricate organization structure, dynamic environment, and financial strain. The study aims to categorize the influencing factors into three groups, namely construction project system, economic-market climate, and external environment. It attempts to adopt a novel analysis tool to examine the relationship between the project cost and multiple influencing factors by using Bayesian SEM. While the Bayesian SEM method has been receiving increasing attention in exploring the relationship between latent variables, construction studies still heavily rely on the covariance-based SEM approach. This study introduces several advantages of Bayesian SEM that make it more flexible and powerful than covariance-based SEM and provides the foundation of Bayesian SEM estimation and inference by illustrating this method in a project cost application.

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