Model for Evaluating Uncertain Project Duration Considering Construction Interface Problems

2013 ◽  
Vol 479-480 ◽  
pp. 1160-1169
Author(s):  
Shih Hsu Wang ◽  
Yu Ting Lai ◽  
Jang Jeng Liu ◽  
Wei Chih Wang

Many probabilistic scheduling models have been developed to determine the duration of construction projects. However, these models are not appropriate to capture the effect of the factors that are involved construction interface problems on the durations of multiple activities. This work presents a simulation-based probabilistic scheduling model that includes the impact of construction interface problems on the duration of building projects. The proposed model is established according to an activity duration model and a work-group (WG)-based schedule network. The activity duration model is applied to reflect the effects of general factors on the duration of each activity; the WG-based schedule network is employed to evaluate the effects of construction interface problems on the durations of multiple activities. The results of applying the proposed model to an example project reveal that the duration of a project can be over-optimistically estimated if the effects of construction interface problems are neglected.

2020 ◽  
Vol 6 (2) ◽  
pp. 5-19
Author(s):  
Elena M. Volkova

The article reviews the world experience in the construction and operation of high-speed railways in terms of factors that determine the success or failure of such projects. Since the construction of HSR is often considered as a part of national projects on a broader scale, it is proposed to use as criteria for success not only commercial indicators, but also various socio-economic effects arising from their implementation. The author classifies externalities that reflect the impact of HSR on the development of regions and cities and presents the results of foreign research on their quantitative and qualitative analysis. Special attention is paid to the experience of China, since this country significantly differs from the rest of the world in terms of development of high-speed rail traffic. In this regard, the largest amount of representative data that allows us to identify the success factors of HSR projects can be found for Chinese projects. The main scientific result of this article is a generalization of the existing experience of HSR construction projects and justification of the prospects for implementing such projects in the Russian Federation.


2021 ◽  
Vol 28 (1) ◽  
pp. 118-129
Author(s):  
Ibrahim Mahamid

This study is conducted to establish the effect of design quality on project delay in building projects. It aims at: 1) investigating the major factors of design quality, 2) identifying the main delay factors in building projects, 2) establishing the relationship between design quality and delay in building projects. To achieve these objectives, a questionnaire survey is performed. Seventeen (17) factors that might affect design quality, and 15 delay factors are listed in a questionnaire form. Sixty (60) contractors and 40 consultants are asked to identify the severity of the identified factors. Results indicate that the top factors affecting design quality are: delay in payments by client for design services, staff allocation for many projects at the same time, copying and modifying from previous work to minimize time and cost, tight design schedule, lack of designer knowledge with techniques and materials available in the market. The study also concludes that the top five delay factors include: payments delay, poor labor productivity, lack of skilled manpower, frequent change orders and rework. Regression analysis for data collected from 36 building projects shows a good correlation between design quality and delay in projects. This study is the first one that addresses the problem of design quality in the West Bank in Palestine. Furthermore, it is the first study that addresses the effect of design quality on project delay in Palestine and the neighboring countries. It is hoped to be helpful for researchers and professionals to understand the impact of design quality on schedule delay.


2018 ◽  
Author(s):  
Mohammad afsharniya

Present objective of the study the effects of pure thinking on the management of the supply chain housing construction projects Foundation in Gulistan province. Research methodology used in this study, descriptive and of solidarity. All statistical community managers and experts active construction projects in the time of the study can be - that their number is estimated at 370 people. The number of 189 people. For the sample was selected. In this study sampling method is random. Gathering information tool that it was standard questionnaires to confirm the validity of experts and professors expert. For reliability questionnaire Cronbach's and other related indicators used their results confirm that represents the reliability of the questionnaire. The questionnaire using factor analysis was confirmed by LISREL software. Research hypotheses were examined using multivariate regression. Research results showed that pure thinking on the management of the supply chain construction projects in the Gulistan province. It also intended to determine the value, making the uninterrupted pursuit of perfection and impact. Pure and fairly new management to reducing time, cost and waste and raising the quality of the pure of construction, and its interaction with supply chain management in order to achieve their objectives and principles.


2002 ◽  
Vol 29 (2) ◽  
pp. 267-275 ◽  
Author(s):  
Sou-Sen Leu ◽  
Tzung-Heng Hung

To meet the physical limits of construction resources, to avoid day-to-day fluctuation in resource demands, and to maintain an even flow of application for construction resources, resource leveling is needed in the construction industry. Traditional resource leveling models assume activity durations to be deterministic. Nevertheless, activity duration may be uncertain, owing to variations in the overall environment, such as weather, site congestion, and productivity level. A new optimal construction resource leveling model is proposed in this paper, in which the combinative effects of both uncertain activity duration and resource leveling are taken into consideration. Monte Carlo simulation is used to model the uncertainties of activity duration. A searching technique using genetic algorithms (GAs) is then adopted to search for the impact of uncertain activity durations on the probabilistic optimal resource leveling indices. The model can effectively provide probabilistic optimal resource leveling indices for multiple construction resources subjected to the objective of resource leveling, and the impact of influence factors on the probabilistic resource-leveling scheduling problems.Key words: resource leveling, genetic algorithms, simulation, probabilistic scheduling.


2011 ◽  
Vol 17 (4) ◽  
pp. 529-539 ◽  
Author(s):  
Ming-Chiao Lin ◽  
Hui Ping Tserng ◽  
Shih-Ping Ho ◽  
Der-Liang Young

The delay of vast building projects is still a common problem. This situation is extraordinarily severe to steel reinforced concrete (SRC) building projects that keep going to promote a new structure system in Taiwan's construction industry. The aim of this study is to develop a feasible contract duration model based upon few SRC building cases. A logical approach is employed to select and assure the “good” regression model identified when project characteristics were known and external uncertainties were reasonably estimated. Different necessary diagnostics had been adopted to examine the aptness of the model before inference. The cross-validation is used to validate the appropriateness of the variables selected and magnitudes of the regression coefficients. The mean of the square prediction errors (MSPR) is selected to measure the predictive ability of the model proposed, and the result shows that the predictive ability of the selected regression model could be adequate. Finally, several cases are taken to test the predictive accuracy of the model proposed, and the result shows that the actually necessary construction duration is considerably closed to the duration predicted by the mode. It is concluded that the predictive duration model proposed could be applicable to the SRC construction projects with a reasonable reliability. Santrauka Vėlavimas realizuojant stambius statybų projektus tebėra dažna problema. Ši situacija ypač rimta dirbant su gelžbetoninių statybų projektais, kuriais populiarinama naujų konstrukcijų sistema Taivanio statybų sektoriuje. Šiuo tyrimu siekiama sukurti tinkamą sutarties trukmės modelį, pagrįstą keliais gelžbetoninės statybos atvejais. Atrenkant ir užtikrinant, kad būtų sudarytas ,,geras“ regresijos modelis, kai projekto savybės žinomos, o išoriniai neapibrėžtumai pakankamai įvertinti, taikytas loginis metodas. Prieš darant išvadas modelio tinkamumas buvo išnagrinėtas naudojant skirtingas būtinos diagnostikos priemones. Naudojant kryžminį patikrinimą pagrindžiamas pasirinktų kintamujų tinkamumas ir regresijos koeficientų vertės. Siekiant įvertinti siūlomo modelio tinkamumą prognozuoti, apskaičiuotos vidutinės kvadratinės prognozavimo paklaidos (angl. Mean of the Square Prediction Errors, MSPR). Rezultatas rodo, kad pasirinktasis regresijos modelis prognozuoja gana gerai. Pagaliau pasirinkus kelis atvejus išbandomas siūlomo modelio prognozių tikslumas. Rezultatas rodo, kad faktinė bū tina statybų trukmė gana artima modelio prognozuojamai trukmei. Daroma išvada, kad siūlomą trukmės prognozių modelį galima taikyti gelžbetoninės statybos projektuose, o jo rezultatai bus gana patikimi.


2019 ◽  
Vol 5 (2) ◽  
pp. 25
Author(s):  
Salhi Roumeissa

Project success is the ultimate goal of the various project stackeholders (Salhi.R 2018). Asuccessful project means that the project is completed on time, within the agreed budget and according to the contract specifications. Delay is one of the most reccuring problems in construction project in Algeria, and it is considered as the main cause of cost overrun, time overrun, disput and claims.The objective of this paper is to mesure the impact of schedule delay on cost overrun, using the simple linear regression method and the coefficient of correlation. The proposed model can be used by practitioners as predictive mesure to address possible cost overrun.


Buildings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 93 ◽  
Author(s):  
Hussein Abdellatif ◽  
Adel Alshibani

There have been many studies done on the causes of delay on construction projects and building projects all around the world. They use different methods, on different geographical areas, and they come up with different results. There are, however, few studies on industrial and building projects. This paper focuses on industrial/manufacturing projects in Saudi Arabia. The aim of this paper is to identify the major causes of delay in the manufacturing projects in Saudi Arabia. The top causes of delay have been identified through a literature survey and interviews with experts from the industrial field in Saudi Arabia. Twenty-two factors have been identified and listed in a survey that was distributed to professionals in the same field. Two categorizations were made: the first is based on the impact of the cause, and the second is based on the frequency of occurrence of the identified cause. It has been found that the top five impacted causes of delay in the delivery of industrial projects in Saudi Arabia are: difficulties in financing project by contractor/manufacturer, late procurement of materials, late delivery of materials, delay in progress payments, and delay in approving design documents, respectively. In terms of frequency, the top five identified causes are: delay in progress payments, difficulties in financing project by contractor/manufacturer, slowness in decision making, late procurement of materials, and delay in approving design documents, respectively. The diversity of the participants is an important point; therefore, the respondents were from different job positions (management, engineering, etc.), and different categories (contractor, owner, manufacturer, consultant, etc.). It is worth noting that this paper serves not only as an authentic study of the causes of delay in the delivery of industrial projects in Saudi Arabia which is a field that is not widely covered, but also as a fresh paper that gives an indication of the changes that happen to the business over time as compared to previous work.


2019 ◽  
Vol 5 (2) ◽  
pp. 25
Author(s):  
Salhi Roumeissa

Project success is the ultimate goal of the various project stackeholders (Salhi.R 2018). Asuccessful project means that the project is completed on time, within the agreed budget and according to the contract specifications. Delay is one of the most reccuring problems in construction project in Algeria, and it is considered as the main cause of cost overrun, time overrun, disput and claims.The objective of this paper is to mesure the impact of schedule delay on cost overrun, using the simple linear regression method and the coefficient of correlation. The proposed model can be used by practitioners as predictive mesure to address possible cost overrun.


2020 ◽  
Vol 38 (7A) ◽  
pp. 1069-1076
Author(s):  
Layth T. Ali ◽  
Raid S. Abid Ali ◽  
Zeyad S. M. Khaled

Cost overrun in construction projects is a common phenomenon in Iraq. This might occur due to diversity of factors. This study aims to identify the factors influencing construction projects cost that are potentially controllable by main contractors. A field study through a questionnaire survey was directed to a sample of related Iraqi professional engineers from general contracting companies at both public and private sectors. Their opinions on the impact and frequency of each factor were investigated. The questionnaire offered (59) factors classified in (8) categories namely; legislations, financial and economic, design, contractual, site management, material, labor and equipment. The factors were ranked according to the highest Relative Importance Index (RII). The study revealed (10) major factors that are potentially controllable by main contractors namely; labor productivity, sub-contractors and suppliers performance, equipment productivity, site organization and distribution of equipment, experience and training of project managers, scheduling and control techniques, planning for materials supply, planning for equipment supply, materials delivery and planning for skilled labor recruitment. Recommendations to aid contractors and owners in early identification of these factors are also included in this study.


2015 ◽  
Vol 3 (2) ◽  
pp. 69-84
Author(s):  
Wadhah Amer Hatem ◽  
Samiaah M. Hassen Al-Tmeemy

     Suicide attacks, bombings, explosions became the part of daily life in Iraq. Consequently, the threat of terrorism put the Iraqi construction sector in the face of unique and unusual challenges that not seen on other countries. These challenges can have extensive impact on construction projects. This paper seeks to examine the impact of the terrorist attacks on construction industry and determine the extent to which the impact of terrorism on construction projects in terms of cost, schedule, and quality. This study adapted quantitative and qualitative approaches to collect data using questionnaire survey and interviews, as well as historical data. The study focused on projects that have been the target of terrorist strikes in Diyala governorate. A variety of statistical procedures were employed in data analysis. The results revealed the extent to which terrorist attacks impact construction projects in terms of cost, time, and quality. The results of this study will enhance the awareness of all construction parties to the impact of the terrorist attacks against construction projects. Eventually, this can develop a risk management assessment and assist contractors to properly protect projects and buildings to minimize injuries and fatalities in the event of terrorism.


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