Forecasting construction cost escalation

1993 ◽  
Vol 20 (4) ◽  
pp. 602-612 ◽  
Author(s):  
Andrew N. Blair ◽  
Leonard M. Lye ◽  
W. J. Campbell

Escalation can account for a substantial part of construction costs. Therefore forecasts of the amount of escalation are required for budgetary and bidding purposes. This paper examines methods for forecasting construction escalation using statistical time series methods. Time series of construction cost indices are used as a proxy of construction cost escalation. The application of time series methods, their limitations, and their effect on the risk of cost escalation are demonstrated and evaluated. The analytical methods available are only useful in forecasting for short construction projects in stable conditions. This is because none of the methods can forecast escalation caused by unpredictable occurrences such as outbreak of war or certain government action. Construction cost escalation remains a risk to be borne by either the contractor or the owner, or both, depending on the terms of the contract; any logical approach to minimize the risk is worthwhile. Key words: construction cost escalation, cost indices, time series forecasting, exponential smoothing. Box–Jenkins methods, dynamic regression, Statistics Canada.

2018 ◽  
Vol 2 (2) ◽  
pp. 42-50
Author(s):  
Abimbola Windapo ◽  
Alireza Moghayedi ◽  
David Oliphant ◽  
AbdulRauf Adediran

This study examines the components of construction projects and whether there are construction resources that are the key project constituents. The rationale for the study stems from the unexplained assumptions regarding the primary components responsible for increases in construction costs in South Africa, as South Africa lacks a national building cost database. The study adopts a qualitative research approach that employs a case studies of six new and six refurbished projects in obtaining the necessary data for use in answering the study objectives. The study found that the primary cost constituents of construction projects are materials and sub-contracted work, accounting for 63.69% and 74.6% of the value of renovation and new construction work respectively and on the average, the major materials by value are reinforcement, cement and filling, while Electrical Installation is the primary sub-contracting item by value. Based on these findings, the study concludes that the future levels of construction work can be predicted knowing levels of specialist sub-contractor costs and building material costs. The study recommends that the sub-contractor and material inputs into construction projects are carefully managed, both on the projects and the construction industry, to limit construction cost increases and cost overruns on projects. The study contributes to the literature on resource planning and control in construction. Keywords: Cement, Construction Cost, Electrical Installation, Reinforcement, Specialist Sub-contractor.


EXTRAPOLASI ◽  
2020 ◽  
Vol 17 (2) ◽  
pp. 1-10
Author(s):  
Michella Beatrix ◽  
Nurul Rochmah ◽  
Gede Sarya ◽  
Pebru Dwijayanto

AbstractLarge and small scale construction projects have waste that cannot be predicted in advance, even the amount cannot be predicted directly, whether it is in large or small amounts. The existence of waste can have a significant impact that can affect construction costs. Waste can have both negative and positive impacts. Good waste management will have a positive impact on the company in terms of cost, even time, and quality, but if the waste that occurs cannot be handled or managed properly it will harm the company in terms of cost, time, and even in terms of quality. In this case, the party that always gets the impact of the waste is the contractor.This study focuses on mitigating the occurrence of waste that is how to minimize it. Thisstudy uses the distribution of questionnaires to the contractor in Surabaya. The results of this study are 5 item indicators on how to minimize the highest ranking. The 5 items are Updating material requirements, Mixing, transporting, and placing concrete at the right time, Increasing the competence and expertise of labor, Provision of good and adequate material/warehouse storage facilities, and accurate material measurement.  Abstrak Proyek konstruksi dalam skala besar maupun kecil, memiliki waste yang tidak dapat diprediksi sebelumnya, bahkan jumlahnya pun tidak dapat diprediksi secara langsung, apakah itu dalam jumlah besar ataupun jumlah yang kecil. Adanya waste dapat memberikan dampak yang signifikan yang dapat mempengaruhi biaya konstruksi. Pada dasarnya waste dapat memberikan dampak negatif maupun positif. Pengelolaan waste yang baik akan memberikan dampak positif bagi perusahaan dalam segi biaya, bahkan waktu dan mutu, namun apabila waste yang terjadi tidak dapat diatasi atau dikelola dengan baik maka akan memberikan dampak negatif bagi perusahaan dalam segi biaya, waktu bahkan dalam hal mutu. Dalam hal ini pihak yang selalu mendapatkan dampak dari adanya waste adalah pihak kontraktorPenelitian ini memfokuskan pada faktor penanggulangan terjadinya waste yaitu cara meminimalisirnya. Penelitian ini menggunakan penyebaran kuisioner kepada pihak kontraktor di Surabaya. Hasil dari penelitian ini adalah 5 item indicator cara meminimalisir yang memiliki ranking tertinggi. 5 item tersebut adalah Updating kebutuhan material, Mencampur, mengangkut dan menempatkan beton pada waktu yang tepat, Meningkatkan kompetensi dan keahlian tenaga kerja, Penyediaan fasilitas penyimpanan material/gudang yang baik dan memadai, dan Pengukuran bahan yang akurat.


2012 ◽  
Vol 2 (2) ◽  
pp. 27-35
Author(s):  
Hong Xiao ◽  
David Proverbs

Construction cost is a major concern to both clients and contractors. Based on a hypotheticalconstruction project (a six-storey concrete framed office building), cost and otherrelated information was collected through a survey of contractors in Japan, the UK and theUS. Using multiple regression analysis it was found that lower overheads, less prefabricatedcomponents, and fewer design variations could reduce construction cost. Overheadslargely represent indirect costs to contractors and if reduced can lead to increased profitlevels and improved competitiveness. The use of prefabricated components may be problematicwhere there are delays in production, insufficient coordination between design andconstruction, and congested transportation on site. Design variations during constructionbring about uncertainties and are disruptive to the construction process. These factorshave paramount impact on construction cost and demand close attention and consideration.Contractors are advised to reduce the costs of their overheads and utilise prefabricationappropriately, while clients and designers should minimise the number of designvariations during construction if better cost performance is desired.


2009 ◽  
Vol 12 (1) ◽  
pp. 104-117
Author(s):  
Tam Thi Minh Nguyen ◽  
Thi Hao Cao

Construction industry is considered to be one of the most important industries in Vietnam's economy. But many construction industry sectors have been experienced chronic problem as cost overrun. Therefore, a conceptual model of factors influencing construction cost was developed to determine the key factors that cause difference between budget cost and actual cost and some solutions are recommended to be applied to achieve the best outcome of cost. The result of analyzing 216 construction projects completed from 2002 to 2007 by companies located in Ho Chi Minh City indicated 6 main factors varying construction cost: project planners, project executives, economics, political, natural environment, fraudulent and lost. The results of multiple linear regression model confirmed the relationship between these above 6 factors and construction cost with the theories are supported at the statistically significant level of 0.05.


1980 ◽  
Vol 21 (1) ◽  
pp. 73-83
Author(s):  
Etsu HASHIDA ◽  
Naohiro YOSHITANI ◽  
Takenobu TASAKI

Author(s):  
Mofazzal H. Khondekar ◽  
Dipendra N. Ghosh ◽  
Koushik Ghosh ◽  
Anup Kumar Bhattacharya

The present work is an attempt to analyze the various researches already carried out from the theoretical perspective in the field of soft computing based time series analysis, characterization of chaos, and theory of fractals. Emphasis has been given in the analysis on soft computing based study in prediction, data compression, explanatory analysis, signal processing, filter design, tracing chaotic behaviour, and estimation of fractal dimension of time series. The present work is a study as a whole revealing the effectiveness as well as the shortcomings of the various techniques adapted in this regard.


Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 1024 ◽  
Author(s):  
Estelle Blons ◽  
Laurent Arsac ◽  
Pierre Gilfriche ◽  
Veronique Deschodt-Arsac

In humans, physiological systems involved in maintaining stable conditions for health and well-being are complex, encompassing multiple interactions within and between system components. This complexity is mirrored in the temporal structure of the variability of output signals. Entropy has been recognized as a good marker of systems complexity, notably when calculated from heart rate and postural dynamics. A degraded entropy is generally associated with frailty, aging, impairments or diseases. In contrast, high entropy has been associated with the elevated capacity to adjust to an ever-changing environment, but the link is unknown between entropy and the capacity to cope with cognitive tasks in a healthy young to middle-aged population. Here, we addressed classic markers (time and frequency domains) and refined composite multiscale entropy (MSE) markers (after pre-processing) of heart rate and postural sway time series in 34 participants during quiet versus cognitive task conditions. Recordings lasted 10 min for heart rate and 51.2 s for upright standing, providing time series lengths of 500–600 and 2048 samples, respectively. The main finding was that entropy increased during cognitive tasks. This highlights the possible links between our entropy measures and the systems complexity that probably facilitates a control remodeling and a flexible adaptability in our healthy participants. We conclude that entropy is a reliable marker of neurophysiological complexity and adaptability in autonomic and somatic systems.


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