Browsing by Author "Ranasinghe, M"

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Analytical approach for economic risk quantification of large engineering projects
(Taylor and Francis, 1992) Russell, AD; Ranasinghe, M
A consistent,four moment based approach for quantifying time and economic risks is presented. The goal is to produce a computationally efficient tool that can be used to explore economic feasibility and tradeoffs between cost and time performance versus risk as a function of various strategies for executing and sequencing major work packages. A three level hierarchy of parameters is used, starting with time, cost and revenue performance at the work package/revenue stream level to rate of return at the overall project level. Use of a four moment approach and Pearson distributions at all levels of the hierarchy permit the formulation of a consistent and readily automated approach to risk measurement. Treatment of correlations is included. A modified form of PNET is presented for quantifying time uncertainty. Use of limiting values (0, 1) of the PNET transitional correlation provide bounds for decision parameters.
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Analytical approach for economic risk quantification of large engineering projects: validation
(Taylor and Francis, 1992) Ranasinghe, M; Russell, AD
Validation and the computational efficiency of an analytical alternative to Monte Carlo simulation for quantifying risks in project performance measures such as time, cost, net present value and internal rate of return are explored in this paper. The analytical approach is based on the use of the Pearson family of distributions, a four moment characterization of uncertainty for input and output variables and a modified version of the PNET algorithm for modelling time uncertainty. The approach is applied to a generalized hierarchical description of a project's economic structure. Results show that the analytical approach can duplicate results of a full-scale Monte Carlo simulation with approximately 0.033 of the computational effort
item: Article-Abstract
BESTCOMP: expert system for Sri Lankan solid waste composting
Jayawardhana, LC; Manipura, A; De Alwis, AAP; Ranasinghe, M; Pilapitiya, S; Abeygunawardena, I
A user friendly expert system, BESTCOMP was developed for better management of solid waste composting by local authorities in Sri Lanka. BESTCOMP expert system mainly focussed on the behaviour of the physical, chemical and biological process in composting. The intention had been to provide distant users with scientific and techno-economic information using modern tools but at a much lower cost. This research has put very strong emphasis on allowing the user to browse around the knowledge that has being extracted from books, published research articles, reports, audio, video, Internet, case studies and the domain experts who involved in solid waste management activities, so the user can get an accurate and a real feel for the solid waste management subject.
item: Conference-Full-text
Better values and characteristics in relationally integrated value networks to enhance total asset management
(Ceylon Institute of Builders, 2014-06) De Silva, N; Ranadewa, KATO; Kumaraswamy, M; Ranasinghe, M; Sandanayake, YG; Fernando, NG; Karunasena, GI
Construction contract types span a wide spectrum ranging from traditional contracting to relational contracting modes. Although weak collaborative supply chain networks exist even in widely practiced traditional contract modes, the potentially beneficial strong relational forces remain untapped and/or fragmented, lacking well-defined common goals among stakeholders. Apart from addressing this shortfall in the built asset planning, design and construction (project management) phase, relational contracts (RC) can also be extended to total asset management (TAM) by aiming at the relational integration of all stakeholders throughout the built asset lifecycle, by engaging them in cross linked value networks’. Such integrated networks were called ‘relationally integrated value networks’ (RIVANS) when initially proposed for the project management phase. ‘RIVANS for TAM’ were next proposed to provide a holistic approach to bridge the project management phase and the asset management phase in the lifecycle of assets. The study reported in this paper, contributes to knowledge by identifying better values through adapting RIVANS as a holistic beneficial approach to the whole built environment. A questionnaire survey was conducted to identify common better values in RIVANS. These identified better values were then clustered to form similar groups using factor analysis to establish synergetic characteristics of RIVANS. Four characteristics were extracted to identify and target embedded synergies in RIVANS, for enhanced total asset management.
item: Conference-Extended-Abstract
BIOCOM-MSW: A composting system for Sri Lankan solid waste management
(2002) Manipura, A; Jayawardhana, LC; De Alwis, AAP; Pilapitiya, S; Ranasinghe, M; Pathinathar, S; Abeygunawardhana, I
Municipal solid waste has become a major problem in every country in terms of public health and environmental damage. As a developing country, Sri Lanka too faces the same challenge not only through public health and environmental damage, but also in finding an affordable yet effective technology, which is socially and economically acceptable. Municipal Solid Waste (MSW) is qualitatively heterogeneous. Therefore it is difficult to find a unique solution for proper treatment, i.e. the solution is always an integrated one, which consists of sorting, biological/thermal/chemical treatment, recycling and land filling." However quantification and characterization of solid waste in a given area are important factors prior to selecting the suitable technology. Therefore, it is required to find waste quantity, composition, density, moisture content, annual growth rate of waste generation and calorific value of waste etc. in a given area. In Sri Lanka, moisture content and organic fraction being reasonably high, and lack of high thermal value materials in the solid waste stream have lead to an overall low calorific value of MSW. The general practice for handling the MSW is low rate composting systems. Most have failed due to poor process management, lack of knowledge of proper operation (feedstock formulation, process control, end point indicators), poor product quality, long lead-time, weaker community participation and lack of public awareness. In all systems existing at present bad odour and leachate are unsolved issues. These systems have largely been controlled by default rather than by design. Thus, losing public confidence on composting is inevitable.
item: Conference-Abstract
The Colombo port city, its major issues and the road to successful implementation
Thoradeniya, DL; Ranasinghe, M
The Colombo Port City Project (CPCP) is regarded as one of the largest and most ambitious Sri Lankan development projects to date. At times classified as a Public-Private Partnership (PPP), the CPCP is a collaborative project between the Government of Sri Lanka and a foreign private entity. The project faced early setbacks and controversy due to several issues, including alleged mishandling of key processes. The aim of this paper is to make recommendations for the successful implementation of the CPCP through the development of a guideline inspired by previous studies on critical success factors for PPPs, supplemented by the results of an analysis of issues surrounding the CPCP. The methodology of the study relies on interviews with key informants, official documentation such as Environmental Impact Assessments, and the literature review. Review of the CPCP indicated that while current feasibility measures covered Economic and Environmental issues through means such as the Extended Cost Benefit Analysis etc., there appears to be inadequate analysis of Political, Social and Legal issues which played a major role in halting the CPCP. Findings highlight the importance of incorporating the analysis of Political, Social and Legal issues beyond what is currently practiced in feasibility studies. It also points towards the necessity of changing current practices, policies and processes relating to PPP or mega development projects in Sri Lanka.
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Contingency allocation and management for building projects
(Taylor and Francis, 1994) Ranasinghe, M
A theoretical approach is presented for contingency allocation and management in building projects using the quantification of uncertainty of project cost. The uncertainty of input items to a bill of quantities, namely, quantities of bill items, usage of resources and their prices are quantified as two moments. From these, two moments for project cost are evaluated. The cumulative distribution function for project cost approximated from its two moments is used to determine the contingency allocation based on a desired probability of success. The management process of this allocation is developed using an approach that establishes initial bench-marks by distributing the allocation to individual bill item costs. By using these initial bench-marks for further distribution, sophistication is introduced to the management process.
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Culture and foreign companies' choice of entry mode: the case of the Singapore building and construction industry
(Taylor and Francis, 2001) Fisher, TF; Ranasinghe, M
Recent studies have shown that culture has an effect on the choice of foreign investment venture structure. Cultural distance has been identified as a primary determinant in the selection of shared control over wholly foreign owned investment. The data from these studies indicate, however, that individual cultural characteristics of investor countries may be more important than the difference in culture. In this study, a sample of Singaporean building and construction firms is utilized to explore whether joint venture (JV) formations correspond more to the uncertainty avoidance dimension of the investor's culture than to cultural distance. The results show that an investor's cultural aversion to risk may be more influential in explaining the propensity for firms from certain countries to engage in JVs, rather than other cultural factors.
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Decision framework for fast-track construction: a deterministic analysis
(1991) Russell, AD; Ranasinghe, M
A deterministic analysis framework that permits the computation of an upper bound on the constant dollar expenditure that should be made to fast-track a project to achieve a specified duration is presented. It employs a baseline plan which corresponds to the traditional method of sequential design, construct, commission and operate, and the economic principle that one will continue to spend as long as the return on the incremental investment equals or exceeds the minimum attractive rate of return. The analysis is based on a generalized definition of fast-track construction, which includes ouerlapping of the construction and revenue phases and acceleration as well as overlapping of design and construction. An example is giuen to illustrate application of the framework.
item: SRC-Report
Development of an expert system for better management of solid waste composting by pradeshiya sabhas in Sri Lanka
Ranasinghe, M; De Alwis, A; Pilapitiya, S; Pathinather, S; Abeygunawardena, I; Jayawardhana, HMLC; Manipura, A
The increasing population and the ever-changing life style of the public have begun to add to the growing solid waste problem in Sri Lanka. As a solution, Local Authorities, NGOs, researchers and environmentalists have implemented several composting projects. Unfortunately, most of these projects are either abandoned or operating under poor conditions due to social, economic and technical problems encountered and none of options have solved the solid waste management problem itself. A key issue that is highlighted is the lack of qualified personnel (experts) to advise and assist Local Authorities to adopt the best solid waste management practices. Decision Support Systems and Expert Systems are favourable tools to overcome these problems. Therefore by capturing past mistakes, weak points and considering past experience, a user friendly Expert System called BESTCOMP was developed for better management of solid waste composting by Pradeshiya Sabhas in Sri Lanka. This research mainly focused on the behaviour of the physical, chemical and biological process in composting. The model is geared towards decision making as well as providing required expertise to solid waste composting hierarchy.
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Development of an expert system for better management of solid waste composting by pradeshiya sabhas in Sri Lanka
Jayawardhana, HMLC; Ranasinghe, M; De Alwis, A; Pilapitiya, S; Abeygunawardena, I
The increasing population and the ever-changing life style of the public have begun to add to the growing solid waste problem in Sri Lanka. As a solution to the growing solid waste management problem in Sri Lanka, Local Authorities, NGOs, researchers and environmentalists have implemented several compo sting projects. As waste characteristics of municipal solid waste in Sri Lanka show a very high proportion of organic matter (60-85%), high moisture content (60- 75%) and low calorific value (l000-1200kcal/kg). Most of these projects are currently abandoned or operating under poor conditions due to social, economic and technical problems encountered and none of options have solved the solid waste management problem itself. A key issue that is highlighted is the lack of qualified personnel (experts) to advise and assist Local Authorities to adopt the best solid waste management practices. Decision Support Systems and Expert Systems are favourable tool to overcome these problems. Therefore by capturing past mistakes, weak points and considering past experience, a user friendly Expert System called BESTCOMP was developed for better management of solid waste composting by Pradeshiya Sabhas in Sri Lanka. This research mainly focused on the behaviour of the physical, chemical and biological process in compo sting. The model is geared towards decision making as well as providing required expertise to solid waste composting hierarchy. BESTCOMP consists of many decision models such as compost process and control, pictorial database, site selection, technology selection, waste analysis reports, expertise information, Government laws and regulation on solid waste management, information desk for researchers and training tool, such that the user can identify problems faster, examine various alternatives and make prudent choices. It performs all the functions of a decision support system. The developed system will guide the Local Authorities of Sri Lanka to find the most suitable composting solution to solve solid waste management problem with the available resources in their area and aid their decision making process on solid waste composting. It also helps in determining resource deficiencies when the user utilizes the data provided in an instructive manner.
item: Conference-Abstract
Distribution of responsibilities and applicability of risk assessments in construction safety
Asanka, WA; Ranasinghe, M
Safety and Health enhancements are tendencies of today‟s construction industry. Accident mitigation measures and legislations are publishing by authorities, enhancing the public awareness. Safety management systems (SMS)are inserting to construction management schemes and it is mandatory in most countries (Singapore, Australia, etc.). Assessing activity based risk or Risk Assessments (RA) is one of the sub elements under SMS. RA is a systematically arranged set of action statements to explain the safest work procedure prior to actual site work. RA‟s are serving effectively in construction sites identifying and mitigating the inherent risks. However, effective practicing of RAs are challengeable due to human behaviour, irresponsibility, negligence or ignorance, result in accidents. Therefore, personal interpretations and appreciation of RAs are timely requirement. This study examined the detailed RAs of “work at height” activities in varying situations. Work at high elevations cause “Fall from height” accidents and it is the leading fatality type in most countries. A questionnaire was launched to investigate the construction professional‟s appreciation, consideration, and ability to implement action statements on work places in Singapore. The findings were extrapolated towards Srilankan industry to trace the way for better safety performance. The objectives of the current research is to (1) quantify risk associated with the current work practices and compare it with the performance-risk due to past accident statistics (2) establish responsibility weightings for the construction team (3) investigate applicability of existing work practices (4) prepare probabilistic data set for the future studies to mitigate accidents. Even though, highly regularised safety and health protocols are enforced in Singapore, construction team‟s ignorance on RA is 13% ~16%, and willingness to take overall site responsibility of supervisor, the key for many SMSs is significantly low as 8%, and further studies are proposing. Anticipated probabilistic accident severities (fatal, major, minor and near misses) due to ignoring these statements are high as 26% ~41%, which also alarms industry to count as additional risk.
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Economic analysis of water infrastructure : have we got it right?
(2016-07-05) Thoradeniya, B; Ranasinghe, M; Wijesekera, NTS
The paper describes shortcomings of the general economic analysis procedure adopted in water infrastructure development projects in Sri Lanka. As a case study an application of the ‘Educated Trade-off’ framework in the Ma Oya river basin is used to illustrate the shortcomings of general economic analysis procedure. This framework facilitates the systematic identification of resource uses and the possible range of environmental and social impacts by the water infrastructure project, through the involvement (consultation and participation) of key stakeholders. The study revealed two types of shortcomings that result in erroneous economic indicators: first, the lack of a competent process to establish the baseline situation leading to non-inclusion of some important social and environmental impacts, both positive and negative, by the project and, second, deviations from reasonable practices either due to negligence or on purposes that give decision makers optimistic data which could result in questionable decisions.
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Economic risk analysis of housing and civil engineering projects
Ranasinghe, M; De Mel, J
“Far better an approximate answer'to the right question which is often vague, than an exact answer to the wrong question, which can always be made precise. John W. Tukey, Annals of Mathematical Statistics, vol. 33, 1962, p.13. 1.1 Background The World Bank in its report on Project Performance stated that about 20% of the development projects completed between 1974 and 1986 determined to be unsatisfactory (see Fig. 1). The “satisfactory” projects between 1974 - 1984 were based on the were • achievement of at least a 10% economic rate of return; • other significant benefits if the economic rate of return was lower; evaluator’s qualitative judgement about the performance if no economic rate of return was calculated. The classifications for 1985 and 1986 were based on achievement of one of the following • wholly satisfactory : project achieves or exceeds all its major objectives, achieves substantial results in almost all respects; • satisfactory : project achieves most of its objectives and has satisfactory results with no major shortcomings; • marginally satisfactory : project reveals major shortcomings in meeting objectives .and/or achievements but is still considered worthwhile.
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Financing of toll highways in Sri Lanka ; reality check
Gunathilaka, KDS; Ranasinghe, M
Highway infrastructure and good road network play important roles in the economic development of a country and their condition affects the economic returns. Traffic congestion is a critical problem due to poor road network and improving the road network properly is essential. Most developing countries like Sri Lanka face difficulties in improving the road infrastructure because of unstable economic conditions and lack of investment funds. As a result few highways of Class A are available in the road network of Sri Lanka and no expressways have been completed so far. The concept of toll highway was initiated during last decade and it was perceived to be a better solution for solving funding problems for expressway constructions in developing countries. It allows private entities to participate, as there are several strategies for financing infrastructure projects on this basis. However, the nation's first toll highway, the Colombo-Katunayake Expressway (CECE) is held up at the construction stage and it lends to the argument that the toll highway concept is not viable for Sri Lanka. This research studies the concept of toll highway together with various issues relating to financing such highways in Sri Lanka in order to check their reality. The analysis is based on a questionnaire survey conducted among 104 respondents of various stakeholder groups. The willingness of vehicle owners and drivers to pay tolls, the impact of time and fuel saving on toll highways in economic terms, the current condition of infrastructure project financing, willingness of investors and bankers to finance toll highways and the reasons for collapse of such projects in Sri Lanka are the key issues analyzed under this research. Traffic congestion is the major problem in today's highway sector. Toll highways came into existence with Private Sector Participation (PSP) for highway investments and it is a good solution for traffic problem as well as overcoming funding problems to expressway constructions. Results of this research show that vehicle owners and drivers do not resist paying tolls for the usage of expressways. In addition, it has been observed that investors and bankers are neutral on financing toll highways in Sri Lanka. They like to finance projects provided that a long-term consistent policy and strong guarantee of the government are available. The findings of this research conclude that toll highways are economically beneficial to Sri Lanka.
item: Conference-Abstract
Grass-root stakeholder involvement for identifying causes for natural disasters in riverine environments: Ma Oya case study
Thoradeniya, B; Ranasinghe, M; Wijesekera, NTS
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Host country requirements for infrastructure project
Tilak, SDL; Ranasinghe, M
The significance of host country requirements in funding projects in terms of emphasising the country needs in foreign investments, have a notable insufficiency during project appraisal stage. In this research, the importance and benefits of host country requirements for funded infrastructure projects is discussed in the context of present situation of most developing countries. This research develops a model, called the Host Country Index (HCI) to incorporate host country requirements effectively in to the infrastructure project. HCr model cross checks the macro planning requirements of host country, against different sectors towards integrated infrastructure development. Based on the feasibility studies of major highway projects in Sri Lanka, a HCr model was developed by this research for analysis of host country requirements in future highway projects. HCr model for highway projects is based on probabilistic framework and develops a project ranking system with different project classifications. These defined project classification and relevant limits for results of application of this model can be used as a tool for measuring the intensity of satisfaction of host country requirements in prospective funding projects. It would give clear advice to the project appraiser in comparing and ranking infrastructure projects. The developed HCI model for highway projects was validated by applying data from two major highway projects in Sri Lanka. The results give clear insights and quick advice from the HeI model on project appraisal by comparing each project with other competing proposals or comparing individual project with standard benchmarks.
item: Conference-Full-text
Impact of aesthetic appearance to facilitate corporate business objectives in organisations
(Ceylon Institute of Builders, 2014-06) Chathuranga, DAK; De Silva, N; Dahanayake, KWDKC; Ranasinghe, M; Sandanayake, YG; Karunasena, GI; Fernando, NG
Aesthetic appearance is a judgment of value based on the appearance of an object. Shapes, proportions, rhythms, scale, degree of complexity, colours, and illumination are the subject matter of formal aesthetics. Aesthetics appearance is an important field in psychology as aesthetics influences the human mind and can lead to psychological reactions, both positive and negative. Creating an aesthetically distinctive identity of development will become an integrated part of the community because user’s state of mind and feeling affected by the emotional elements in design. However, this area has not been addressed in detail. Thus, this research focused to identify and analyse parameters of aesthetic appearance of buildings and their impact towards corporate business objectives of commercial organisations. The research used case study approach and two commercial buildings were selected as cases. Data were collected using semi structured interviews. Data analysis was done using content analysis. Five parameters were established to analyse the aesthetic appearance. Findings revealed that all forms and elements of aesthetic appearance are full of potentially symbolic meanings and have considerable impact on corporate business objectives. Though, there are considerable aesthetic applications as mentioned above, still there are substantial deficiencies in current practices of adaptation of aesthetical appearance for building design in Sri Lankan context.
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Impact of correlation and induced correlation on the estimation of project cost of buildings
(Taylor and Francis, 2000) Ranasinghe, M
Treatment of correlation between variables is necessary for deriving any theoretical distribution of the project cost of buildings. This paper highlights some often ignored theoretical requirements necessary for a rigorous treatment of correlations. The condition for a positive definite correlation matrix is described, along with an analytical procedure and a computer program developed to verify the positive definite condition when correlation coefficients between input variables are estimated using historical data. The analytical procedure and the developed computer program can be used in any application that obtains correlation information from historical data or as subjective judgements to be used in a functional relationship. A new concept called induced correlation is suggested to define and to treat correlation between derived variables that arise from the common (shared) primary variables in their functional forms. A published numerical example is used to highlight the stages where correlation between variables can have an impact on the estimation of moments (estimated expected value and estimated standard deviation) for the project cost of buildings, and to demonstrate the improvement in the estimation of the standard deviation of project cost as a result of treating correlations in risk analysis.
item: Conference-Abstract
Inadequacies of analysis of pre-construction activities on cost overruns in construction projects
Shehara, PLAI; Ranasinghe, M
Cost overrun is considered as one of the critical issues in the construction sector projects in many of the developing countries. It has been identified that preconstruction factors affect mainly on time and cost overruns in construction projects. The focus here is on mainly four preconstruction factors which are selected from review of literature. They are conducting geotechnical site investigations, identification of availability of sufficient knowledge to do the project, identification of availability of skilled labour, identification of required material, machinery and equipment. This research study attempts on identifying the severity of the adequacy of these four pre-construction factors on cost overruns and to develop a relationship between cost overrun variation with the adequacy level of analysis of those pre-construction factors. A thorough review of literature was done to identify the four pre-construction factors and then a questionnaire survey was conducted to obtain the responses from industry experts regarding construction cost overruns related with the adequacy levels of analysis of four factors for a selected project. The survey data obtained were analysed by determining Relative Importance Index, Regression Analysis and Sensitivity Analysis techniques. The results obtained from the analysis techniques are interpreted under this research study based on the limitations.