An assessment of the causes, cost effects and solutions to design-errorinduced variations on selected building projects in Nigeria
14 Jun 2018-Vol. 25, Iss: 1, pp 40-70
TL;DR: The study found that poor working drawing and lack of coordination among design documents are the major causes of variation and variation costs could be minimized if government policies, aimed at ensuring proper contract documentation, were put in place, and construction professionals were limited to their core roles on construction projects.
Abstract: Design errors and variations are inherently part of many construction projects and require deliberate effort to combat. The literature reviewed indicates that empirical studies of the cost effect of design-error-induced variations are scarce. This study investigates the causes of variation on building projects, the frequent design errors that lead to variation, the effects of design error on variation cost, and solutions to design-error-induced variation in design documents. A mixed methods research (interviews and 30 case study building projects) was used to collect the necessary data for the study. Interviews were conducted with 25 construction professionals to obtain information on the causes of variation on building projects and solutions to design-error-induced variation on building construction projects. Thirty documents including valuation breakdowns and variation/change order documents were obtained by convenience sampling technique and used for the extraction of design errors leading to variations and their associated costs. The data was analysed with frequencies and percentages. The study found that poor working drawing and lack of coordination among design documents are the major causes of variation. Errors in design calculations and wrong descriptions in specifications are prominent design errors that led to variation. Design errors account for roughly 36% of the variation cost of building projects. Structural and architectural drawings contain the largest number of errors among design documents, but electrical and mechanical documents have the highest contribution to variation cost. The study concluded that variation costs could be minimized if government policies, aimed at ensuring proper contract documentation, were put in place, and construction professionals were limited to their core roles on construction projects. Rechecking of design documents prior to use, knowledge sharing, and use of computer programs were among the recommended solutions to design-error-induced variation in project documents. Keywords: Construction projects, cost of error, design documents, design error, variation cost, valuation documents
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TL;DR: In this article , the authors proposed a robust random forest (RF) regression model to predict ESCOs considering both project-related and organizational-related variables, and compared the results with those of support vector regression (SVR) and multiple linear regression (MLR), which indicated that with an R2 value of 0.8680 and mean absolute error (MAE) of 3.88, the RF regression model performs better than those baseline models, namely SVR and MLR.
Abstract: Current approaches to automating cost estimation mainly focus on construction costs. Yet, the two main services provided by design firms, namely ‘designing the project’, and ‘supervision of construction operations’ labelled as engineering services, despite their comparatively low cost, can significantly affect the total cost of construction projects as they can engender reworks, changes and disputes on project participants during the subsequent stages of the project. Continuous evaluation of engineering services' cost overruns (ESCO) is quintessentially important in order to prevent consequential problems later on in the project's development and use. Consequently, this research proposes a robust random forest (RF) regression model to predict ESCOs considering both project-related and organizational-related variables. A database consisting of 95 high-rise residential building projects designed during the past eight years in Iran, along with 12 related variables, were collected to develop and validate the model. The results were also compared with those of support vector regression (SVR) and multiple linear regression (MLR), which indicated that with an R2 value of 0.8680 and mean-absolute-error (MAE) of 3.88, the RF regression model performs better than those baseline models, namely SVR and MLR. This research presents two main contributions to the existing body of knowledge. From the practical point of view, it provides an efficient tool for design firms enabling them to screen and prioritize their projects from the cost overrun standpoint and to devise a contingency plan for them. From the theoretical point of view, it revealed that to mitigate ESCOs, three key factors should be given thorough consideration, namely: ‘the level of computer-aided design technologies adoption’; ‘level of communication among the project team’; and scope definition adequacy’ – cumulatively, these three factors contribute to 52.35% of ESCO variations.
18 citations
01 Feb 2021
TL;DR: In this paper, a questionnaire survey to identify the significance of key quality variables was carried out and a total of 139 variables on design documentation quality were used to determine the level of significance.
Abstract: There are numerous studies on design documentation variables without efforts to evaluate their level of importance. Therefore, the aim of this study is to evaluate the significance of these variables towards improving design documentation quality. A questionnaire survey to identify the significance of key quality variables was carried out. A total of 139 variables on design documentation quality were used. The mean score and Standard deviation of each factor were used to determine the level of significance. Based on responses from 112 construction industry players, the significance of each variable is determined. Design documentation is fit for purpose was considered highly important as an attribute while Inadequate and Insufficient documentation was ranked highest for quality influential factors. The findings will provide valuable data to stakeholders, researchers, and academics and will help enhance project performance because professionals will be aware of key factors that can influence design documentation quality. It will also aid in providing solution to sustainable infrastructure design and delivery challenges in the industry. The study offers a pragmatic data and empirical evidence to expand knowledge on design documentation quality. It is the first of its kind that explored the significance of design documentation quality variables based on the outcome of a meta-synthesis.
10 citations
Cites background or methods from "An assessment of the causes, cost e..."
...2 Building Information Modelling (BIM) [7], use of design checklists and establishment of quality control departments [6,8]....
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...3 Design documentation quality variables A study by Dosumu and Aigbavboa [7] on evaluating the causes, effects, and solutions of design error posited lack of coordination between design documentation, poor drawings, omissions, and mistakes, as main factors responsible for poor design documentation quality....
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...A study by Dosumu and Aigbavboa [7] on evaluating the causes, effects, and solutions of design error posited lack of coordination between design documentation, poor drawings, omissions, and mistakes, as main factors responsible for poor design documentation quality....
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...Series: Earth and Environmental Science 654 (2021) 012007 IOP Publishing doi:10.1088/1755-1315/654/1/012007 Building Information Modelling (BIM) [7], use of design checklists and establishment of quality control departments [6,8]....
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...The sector contributes about ten percent (10%) of Gross Domestic Product (GDP) and employs about ten percent (10%) of the labor force in countries around the world [7,11,12]....
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TL;DR: In this paper, the authors developed a forecast and mitigation model of schedule and cost performance during a detailed engineering stage of offshore engineering, procurement, and construction (EPC) projects.
Abstract: The main subject of this research is to develop a forecast and mitigation model of schedule and cost performance during a detailed engineering stage of offshore engineering, procurement and construction (EPC) projects. The weight factors of major elements in detailed engineering completion rating index system (DECRIS) were measured using a fuzzy inference system (FIS) and an analytic hierarchy process (AHP). At five key engineering milestones, from an EPC contract being awarded to the start of construction, detailed engineering maturities were assessed in fourteen historical offshore EPC projects using the DECRIS model. DECRIS cutoff scores for successful project execution were defined at the key engineering milestones. A schedule and cost performance was forecasted and validated through comparison of DECRIS and other models using statistical confidence of a fuzzy set qualitative comparative analysis (fsQCA) and a regression analysis. As a mitigation method for engineering risks to EPC contractors, engineering resource enhancement is recommended for trade-off optimization of cost overrun using a Monte Carlo simulation. The main contribution of this research is that EPC contractors could continuously forecast construction costs and schedule performance utilizing the DECRIS model, and could review the adequacy of engineering resources, assessing the trade-off between said resources and cost/schedule risk mitigation.
8 citations
TL;DR: In this article, the authors proposed that reweeds are unavoidable during the design and construction phases of construction projects and significantly increase the time and cost required to complete projects and the cost of completing projects.
Abstract: Reworks are unavoidable during the design and construction phases of construction projects and significantly increase the time and cost required to complete projects. Several studies have b...
4 citations
TL;DR: In this paper , a comprehensive literature review was conducted, and 212 relevant articles were carefully selected to be reviewed in detail, and the rework indicators in each category were ranked based on how often they were mentioned in the literature and then were weighted using the rank sum method.
Abstract: Reworks are unavoidable during the design and construction phases of construction projects and significantly increase the time and cost required to complete projects. Several studies have been conducted to determine how to mitigate the major consequences of reworks by identifying the critical root causes of the design changes and/or modifications. Multiple researchers and practitioners have concluded that reworks are due to human-, organizational-, and /or project-based changes; however, the existing literature lacks in-depth information pertaining to these rework indicators. The authors of the present study aimed to investigate, identify, and prioritize the organizational-based rework indicators (ORIs), project-based rework indicators (PRIs), and human-based rework indicators (HRIs). A thorough list of strategies to prevent or mitigate the major consequences of PRIs, ORIs, and HRIs was also developed. A comprehensive literature review was conducted, and 212 relevant articles were carefully selected to be reviewed in detail. The rework indicators in each category were ranked based on how often they were mentioned in the literature and then were weighted using the rank sum method. The PRIs, ORIs, and HRIs were classified and weighted by their attributes, then were compared with one another. The results revealed that poor design, lack of communication, and inexperienced workers were the first-ranked rework indicators in the project, organization, and human categories, respectively. It was also concluded that the attributes of leadership and management, error and inefficiency, and skill and experience received the highest weights among the attributes belonging to the organization, project, and human categories, respectively. The findings of this study will help decision makers timely identify the main causes of construction reworks and enable them to allocate resources for preventing and/or mitigating their cost and frequency of occurrence.
4 citations
References
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Book•
18 Aug 2006TL;DR: This book discusses writing and Evaluating Mixed Methods Research, and the importance of knowing the structure of the writing so that it Relates to the Designs Evaluating a Mixed Methods Study Within Designs.
Abstract: List of Tables List of Figures Preface Purpose of This Book Audience for the Book Book Features Acknowledgments Chapter 1: Understanding Mixed Methods Research Purpose and Organization Clarifying Terms What Is Mixed Methods Research? The Importance of Mixed Methods Research Summary Activities Additional Resources to Examine Chapter 2: Examining Preliminary Considerations Consider Worldview Stances The Basics of Quantitative and Qualitative Research Research Problems Addressed by Mixed Methods Summary Activities Additional Resources to Examine Chapter 3: Locating and Reviewing Mixed Methods Studies Searching for and Reviewing Mixed Methods Studies A Mixed Methods Notation System and Visual Diagrams Four Examples of Mixed Methods Studies Summary Activities Additional Resources to Examine Chapter 4: Choosing a Mixed Methods Design Classifications of Mixed Methods Designs The Four Major Types of Mixed Methods Designs Selecting a Type of Mixed Methods Design Implementing the Design Decisions Writing a Paragraph to Identify a Study's Design Summary Activities Additional Resources to Examine Chapter 5: Introducing a Mixed Methods Study Writing a Mixed Methods Title Stating the Problem in the Introduction The Purpose Statement Research Questions and Hypotheses Summary Activities Additional Resources to Examine Chapter 6: Collecting Data in Mixed Methods Research Procedures in Qualitative and Quantitative Data Collection Data Collection in Mixed Methods Design Summary Activities Additional Resources to Examine Chapter 7: Analyzing Data in Mixed Methods Research Procedures in Quantitative and Qualitative Data Analysis Data Analysis With Mixed Methods Designs Summary Activities Additional Resources to Examine Chapter 8: Writing and Evaluating Mixed Methods Research General Guidelines for Writing Organize the Structure of the Writing So That It Relates to the Designs Evaluating a Mixed Methods Study Within Designs Summary Activities Additional Resources to Examine Chapter 9: Questions Often Raised About Mixed Methods Research Anticipate Mixed Methods Questions What Is Mixed Methods Research? Is Mixed Methods Research Accepted? Is Mixed Methods Research Realistic? Summary Activities Additional Resources to Examine Chapter 10: Future Directions for Mixed Methods Research Needed Developments in Mixed Methods Research Summary Activities Additional Resources to Examine Appendix A. A Triangulation Design Appendix B. An Embedded Design Appendix C. An Explanatory Design Appendix D. An Exploratory Design References Index About the Authors
23,221 citations
"An assessment of the causes, cost e..." refers methods in this paper
...The reason for collecting both quantitative and qualitative data is to elaborate on specific findings from the breakdown of the valuation and variation documents, such as similar causes of design errors and variation suggested from respondents’ groups (Creswell, 2005; Creswell & Plano-Clark, 2007)....
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Book•
12 Jul 2001
TL;DR: In this article, the authors present an introduction to the process of conducting research, including the steps in the procedure of identifying a research problem, defining a purpose and research questions or hypotheses, and analyzing and interpreting quantitative data.
Abstract: Part I: AN INTRODUCTION TO EDUCATIONAL RESEARCH. 1. The Process of Conducting Research. 2. Quantitative and Qualitative Approaches. Part II: THE STEPS IN THE PROCESS OF RESEARCH. 3. Identifying a Research Problem. 4. Reviewing the Literature. 5. Specifying a Purpose and Research Questions or Hypotheses. 6. Collecting Quantitative Data. 7. Analyzing and Interpreting Quantitative Data. 8. Collecting Qualitative Data. 9. Analyzing and Interpreting Qualitative Data. 10. Reporting and Evaluating Research. Part III: RESEARCH DESIGNS. 11. Experimental Designs. 12. Correlational Designs. 13. Survey Designs. 14. Grounded Theory Designs. 15. Ethnographic Designs. 16. Narrative Research Designs. 17. Mixed Methods Designs. 18. Action Research Designs. Appendix A: Answers to the Chapter Study Questions. Appendix B: Determine Size Using Sample Size Tables. Appendix C: Non-Normal Distribution. Appendix D: Strategies for Defending a Research Proposal. Glossary. References. Author Index. Subject Index.
13,492 citations
TL;DR: It is concluded that the choice of the techniques (Convenience Sampling and Purposive Sampling) depends on the nature and type of the research.
Abstract: This article studied and compared the two nonprobability sampling techniques namely, Convenience Sampling and Purposive Sampling. Convenience Sampling and Purposive Sampling are Nonprobability Sampling Techniques that a researcher uses to choose a sample of subjects/units from a population. Although, Nonprobability sampling has a lot of limitations due to the subjective nature in choosing the sample and thus it is not good representative of the population, but it is useful especially when randomization is impossible like when the population is very large. It can be useful when the researcher has limited resources, time and workforce. It can also be used when the research does not aim to generate results that will be used to create generalizations pertaining to the entire population. Therefore, there is a need to use nonprobability sampling techniques. The aim of this study is to compare among the two nonrandom sampling techniques in order to know whether one technique is better or useful than the other. Different articles were reviewed to compare between Convenience Sampling and Purposive Sampling and it is concluded that the choice of the techniques (Convenience Sampling and Purposive Sampling) depends on the nature and type of the research.
4,956 citations
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01 Jan 1978
TL;DR: In this paper, the authors present a project delivery system for CPM construction, which is based on the Project Delivery System (PDS) and a set of specifications and drawings.
Abstract: 1. The Project Delivery System. 2. Responsibility and Authority. 3. Resident Inspection Office Responsibilities. 4. Documentation: Records and Reports. 5. Specifications and Drawings. 6. Using the Specifications in Contract Administration. 7. Construction Laws and Labor Relations. 8. Construction Safety. 9. Meetings and Negotiations. 10. Risk Allocation and Liability Sharing. 11. Preconstruction Operations. 12. Planning for Construction. 13. Fundamentals of CPM Construction Scheduling. 14. Construction Operations. 15. Value Engineering. 16. Measurement and Payment. 17. Construction Materials and Workmanship. 18. Changes and Extra Work. 19. Claims and Disputes. 20. Project Closeout. 21. Bibliography. 22. Index. 23. Forms Index.
181 citations
"An assessment of the causes, cost e..." refers background in this paper
...Fisk (1997) stated that the two basic types of variation are direct and constructive changes....
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