Long D. Nguyen

A study on project success factors in large construction projects in Vietnam

Large construction projects are inherently complex and dynamic. A comprehensive answer on how to manage such projects successfully is difficult to provide. This paper expounds on the success factors for large construction projects in Vietnam. A survey questionnaire was used to collect data from practitioners. Factor analysis was employed to categorize these success factors perceived by 109 respondents from 42 construction‐related organizations. Factor analysis uncovered that these success factors can be grouped under four categories, here titled the four COMs: comfort, competence, commitment, and communication. The result can be used as a guideline to successfully handle construction projects in Vietnam as well as in other countries, especially in the emerging economies in Asia and the rest of the world.

Analysis of Adverse Weather for Excusable Delays

Severe weather conditions can be disruptive to construction. Contractors typically obtain time extensions for weather days beyond normal conditions. However, contracting parties often dispute the extent of weather-related time extensions. Typical industry contracts may overlook many important points that can provide an acceptable resolution. This paper classifies seven factors causing discrepancies in analysis of adverse weather for time extensions; namely, the definition of normal weather, weather thresholds, type of work, lingering days, criteria for lost days, lost days equivalent due to lost productivity, and work days lost versus calendar days lost. An analysis of an actual weather-caused delay claim illustrates the impacts of those factors on the outcomes of the analysis. A contract should define anticipated weather delay days and their lingering days and provide threshold values for weather parameters to differentiate between predictable and unpredictable severe weather. The contract should clearly define how a time extension is granted in calendar days as a result of work days lost, and also address how a time extension is granted due to inefficiency caused by unusually severe weather. Future research may provide an appropriate mechanism for analyzing equivalent lost days to account for lost productivity.

Simulating Construction Duration for Multistory Buildings with Controlling Activities

AbstractConstruction schedules are uncertain in nature; therefore, predicting construction duration is a difficult task. Extensive research has proposed mathematical models to predict construction duration based on regression analysis, Monte Carlo method (MCM), and so on. Yet regression analysis cannot capture duration uncertainties. Studies normally use Monte Carlo methods to simulate hundreds to thousands of activities in a project schedule. This can be complicated, time-consuming, and unrealistic because the statistical properties of all the activities cannot be readily determined in practice. Typical construction sequences in condominium building construction were first identified, and then the statistical distributions of controlling activities on the sequences were surveyed. Two-stage questionnaire surveys and goodness-of-fit statistical tests were conducted to achieve the mentioned objectives. Subsequently, a model for predicting the duration of building construction was proposed and applied to a h...

Concurrent Delays and Apportionment of Damages

This paper focuses on the subject of concurrent delay from a general contractor (GC)-subcontractor perspective. When there is a concurrent delay by multiple subcontractors, or between the GC and other subcontractor(s), there has not been a uniform approach as to how the liquidated damages are apportioned. Previous research seems to ignore this issue. This paper first reviews some relevant court cases. Using a warehouse project as a case study, it then examines different practices that the GC could take in apportioning damages of concurrent delays to both himself/herself as well as to the responsible subcontractors. Results are very inconsistent between and within the apportionment practices. This supports an alternative hypothesis that apportionment is an important issue. Practitioners should specify which apportionment practice will be used and under what circumstances it will be applied in their subcontracts. Researchers may develop a more consistent and reliable approach for this type of apportionment.

Relationship between Floor Number and Labor Productivity in Multistory Structural Work: A Case Study

Construction activities are repetitive from floor to floor in multistory building construction. Labor productivity may neither reach 100 percent of the normal level at the very first floors nor the very top floors. Nevertheless labor productivity may follow a certain pattern as construction activities progress. This research aims at exploring the relationship between floor number and labor productivity in multistory structural activities, namely formwork installation and rebar fabrication/installation. The case study methodology and learning curve theory are adopted for this research. Records from the structural works of an apartment building were analyzed to calculate floor number-based labor productivities for the two investigated activities. The unit rate of the formwork activity reduced more than 50 percent in the first five floors. If the first cycle (floor 2) is omitted, the straight-line learning curve model shows a learning rate of 83.5%. Productivity of the formwork activity tended to level off in the remaining thirteen floors. The unit rate of the rebar activity was prone to reduce in the first fifteen floors. If the first two cycles are omitted, the straight-line learning curve model indicates a learning rate of 83.6%. If only the first cycle is omitted, the learning rate of the rebar activity is 87.9%. Productivity of the rebar activity tended to decrease in the last three top floors though data points were not adequate to confirm such pattern.

A smart mobile app for site inspection and documentation

Extensive time and effort are spent on inspecting and documenting construction defects for facilities under construction or in use. The goal of this study is to provide construction engineers and experts with a smart mobile application to efficiently record and document construction defects. This study first investigated typical inspection processes, data, and reports which were used in site inspections in practice. An Android-based mobile application called InSite Inspector (Intelligent Site Inspector) was then developed to facilitate site inspection and documentation. This smart app is able to: (i) take images and catalog details of construction defects such as defect types, construction trades, building components, and date and time; (ii) automatically locate defects using the global positioning system (GPS); and (iii) produce various types of reports for different inspection purposes such as punch lists and defect reports. The inspectors are allowed to customize the app features such as text entries, type of data to be recorded and/or reported to meet their specific inspection requirements. Additionally, the InSite Inspector allows engineers and experts to manage different construction sites, inspections, and to keep track of past and ongoing inspections. Finally, the app can be used to save, email, or upload the resulting reports to cloud-based repositories. An inspection case study was used to demonstrate the application and utilities of this development. The InSite Inspector is expected to significantly streamline site inspection and documentation processes.

Relationship between building floor and construction labor productivity

Purpose – The purpose of this paper is to examine the relationship between building floor and labor productivity of the structural work including formwork installation and rebar fabrication/installation. Design/methodology/approach – The case study methodology and learning curve theory are adopted for the paper. Records from the structural work of a 20-storey apartment building were analyzed to calculate floor-based labor productivities. Findings – Labor productivity of the formwork activity increased more than twice in the first five floors. If the first cycle (floor 2) is omitted, the straight-line learning curve model shows a learning rate of 83.5 percent. Labor productivity of the rebar activity tended to increase in the first 15 floors. If the first two cycles are omitted, the straight-line learning curve model indicates a learning rate of 83.6 percent. Research limitations/implications – Future research is needed to examine and quantify factors that affect the level of learning in high-rise building...

Influence of Participants’ Characteristics on Sustainable Building Practices in Emerging Economies: Empirical Case Study

AbstractThe slow development of green building (GB) practices in emerging economies has resulted in these countries remaining dominated by uncertified conventional buildings, which has caused negat...

Examination of communication processes in design-build project delivery in building construction

Design-Build (D-B) is a project delivery method in which the owner procures both design and construction services in the same contract from a single legal entity. There is limited research on how communication among parties influences the success of D-B projects. The purpose of this paper is to examine D-B communication issues and provides effective practices on communication to improve D-B procurement processes in the USA.,The research methodology for this study includes a comprehensive review of literature, survey questionnaire, and structured interviews. A questionnaire was developed to collect data from professionals with an average of 23 years of experience related to D-B procurement. Eight structured interviews were conducted to verify and validate the survey questionnaire results.,The results showed that the communication issues vary along with each phase of the D-B process. The primary communication practices influencing the success of D-B projects are: establishing clear points of contact; providing clear and understandable information among stakeholders during the D-B process; and the timely sharing of information to all stakeholders.,The chief limitation of this research is that the primary data were mostly opinions from experts although several empirical data were collected for cross-validation. This research did not consider the relationship of relevant contract clauses and communication issues.,The findings from this paper will help professionals better understand the D-B procurement process.,This is one of the first attempts to discuss D-B communication issues in each different phase of a D-B project.

Computational model for measuring project complexity in construction

As construction projects are increasingly complex, a systematic approach for assessing their complexity is imperative. The Fuzzy Analytic Hierarchy Process (Fuzzy AHP) method was employed to determine the local and global weights of the criteria and sub-criteria in project complexity. The overall project complexity is quantified by a proposed measure, named complexity level (CL). A computational model was developed in MATLAB to facilitate calculations in Fuzzy AHP, conduct sensitivity analysis, and visualize results. The application of the model was illustrated in a case study of three transportation projects performed by a heavy construction company. The proposed complexity level enables engineers and managers to better anticipate potential difficulties in their complex construction projects. Scarce resources will be therefore allocated efficiently in various construction projects in a companys portfolio.