Doctor of Philosophy (Ph.D.)

Permanent URI for this collectionhttp://192.248.9.226/handle/123/13773

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    item: Thesis-Abstract
    A comprehensive evaluation process for transport projects
    (2021) Weerawardana WJ; Kumarage AS; Sivakumar T
    demand imposing immense pressure on many governments primarily due to scarcity of the public resources required to implement them. This particular context demands the governments and other related agencies to allocate public resources efficiently when investing in transport projects. Thus, the evaluation of transport projects becomes an important feature as it indicates how efficiently resources can be or were allocated to a given project. Nonetheless, the literature does not reveal a collectively agreed-upon process for evaluating transport projects despite its rationalization being accepted from the mid 19th century. The processes predominantly using to evaluate transport projects range from the single-criteria cost-benefit analysis (CBA) to the multi-criteria analysis (MCA) methods and their different combinations. CBA is often criticized for its input- incompleteness raised due to inability to cope with non-monetizable impacts while MCA for its result-incompleteness raised due to those results not being able to demonstrate the implementation feasibility of projects and comparable absolutely. Thus, the most recent trend, combining CBA and MCA, is becoming more popular globally as it is capable of negating each other’s disadvantages to a certain extent. However, even these combined models have failed to sort result-incompleteness effectively, primarily due to using MCA methods as their platforms. In view of solving the said input and result-incompleteness issues in existing processes, this research aimed to develop a new evaluation process for transport projects capable of ensuring (i) inputcompleteness by taking both monetizable and non-monetizable impacts into account and (ii) result-completeness by producing results enabling to test the implementation feasibility of each evaluated project and their performance-based prioritization. This new evaluation process, termed as comprehensive evaluation process (CEP), was formulated by first establishing a Theoretical Comprehensive Evaluation Process (TCEP) using an inductive approach and then functionalizing it through an approach of deductive reasoning. The TCEP was developed on a MCA platform, ensuring input and resultcompleteness, and minimizing MCA method related issues such as subjectivity, arbitrariness, and double counting, and common issues of transparency, robustness, simplicity, and accountability. The functionalization improved the practicality issues associated with the TCEP in solving transport project evaluation problems and eventually established the Functionalized Comprehensive Evaluation Process (FCEP). Such formulated FCEP was incorporated with a methodological adjustment to test the implementation feasibility of each evaluated project and thereby established the CEP. The CEP ascertains both input and result-completeness in its practical application to solve transport project evaluation problems and hence achieves originally set features for the new evaluation process in the research aim. This new process was demonstrated by applying it to an evaluation problem targeted to improve public transportation on the Galle Corridor in Sri Lanka. The results of the same demonstration were compared with their originals estimated using the CBA to validate the CEP justifying deviations through rational reasoning.
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    item: Thesis-Full-text
    Identification and modelling of construction supply chain risk triggers
    Sugathadasa, PTRS; Kumarage, AS; Styger, L
    The primary research problem was to identify and study the nature of triggers of construction supply chain risks within the context of the Sri Lankan construction industry. All of the important supply chain risk owners of the construction supply chains such as construction contractors, materials suppliers, consultants, client and construction industry as a whole as well as risk triggers created by them were considered in the research and this level of research has not been conducted before. The construction supply chain risk triggers are identified and categorized under construction industry specified risks, stakeholder generated risks and materials supply related risks. Stakeholder generated risks are further categorized as client generated risks, consultant generated risks and contractor generated risks. This is the first time in the literature, which used a holistic categorization for construction supply chain risks. Construction industry specified risk triggers are all types of risks from the construction industry/country/global context which are broken into the sand problem, regulations, seasonal trends and labour problem. Stakeholder generated risks triggers are contractor generated risks, consultants generated risks, and client generated risks. Contractor generated risks triggers are planning risks, decision making risks, financial risks, communication risks and sub-contractor risks. Client generated risk triggers are risks on communicating the scope of work and risks on fund supply. Consultant generated risks triggers are risks on submitting accurate designs and estimates. Materials supply related risk triggers are materials supply related quality risks, materials supply related availability risks, materials supply related on time delivery risks, materials supply related price risks. This is the first time in the literature, which used risk triggers to classify construction supply chain risks. Further, the research presents an interaction model the Risk Relationship Diagram (RRD) explaining the risk triggers and their impacts in the construction supply chains considering all the supply chain partners. The RRD can be used as a tool to assess the impact of triggers created by each stakeholder on others or how the triggers created by other stakeholders will affect each stakeholder. The model is useful in academic and practitioner perspective to investigate risk triggers at various points of the supply chain and to assess the risks and mitigation methods. Equations are derived to explain the relationship between each of the risk owners and respective risk triggers. Using the respective equations, each respective risk owner generated risk in value of money or time for a past project/contractor/consultant/client/materials supplier can be calculated. Using the answer, the perceived risk for each of the respective risk trigger for future similar project/contractor/consultant/client/materials supplier can be calculated. Using this model, the total risk impact for a given construction project can be derived. It is identified that the human generated risks, infrastructure/resource limitation risks and unavoidable risks are deep rooted primary risk triggers of any of the construction supply chains. However, the results presented are based on the Sri Lankan context and when the findings are applied for different socio economic context, the methodology explained can be used to a good extent but the models should be verified with the new context-This study reveals the risk profile of the Sri Lankan construction industry also. Further, twenty five risk topics were identified for the Sri Lankan construction supply chains. This research reveals twelve methods of risk identification as a holistic approach of construction supply chain risk identification. The methods can be used with suitable modifications to identify risks in any other supply chain also. The Double Triangulation Methodology introduced in this research can be applied in other research as a viable research methodology. In the Double Triangulation Methodology, it is suggested that it is compulsory to validate the results using minimum two other different data sets/two other approaches (ex: both qualitative and quantitative approaches).