This paper provides a comprehensive comparison between two groups of nondeterministic scheduling ... more This paper provides a comprehensive comparison between two groups of nondeterministic scheduling methods : 1) probabilistic and 2) fuzzy set based methods. A numerical example is used to demonstrate the differences between the two groups of methods. The comparison is conducted considering three aspects : 1) theoretical assumptions, 2) data acquisition and computational effort , and 3) scheduling information. The results indicate that the fuzzy network method can overcome some of the limitations associated with PERT and Monte Carlo simulation. The fuzzy network method is capable of providing realistic and useful information to the project team.
There is need to enhance our understanding of the behavior of various infrastructure networks and... more There is need to enhance our understanding of the behavior of various infrastructure networks and their components when subjected to different sets of conditions. This study uses artificial neural networks, to investigate the importance and influence of certain attributes of sewer pipes, upon their structural performance. Data on six parameters related to sewer pipeline including: pipe length, diameter, depth/cover, pipe material, bedding condition, pipe age and closed circuit television based pipe condition rating, were obtained from the municipality of Pierrefonds Quebec. Back propagation and Probabilistic neural network models were developed and validated. These models were used to rank the parameters, in the order of their influence on pipe condition. Sensitivity analysis was carried out to simulate the structural condition of pipe at a range of values of each of the above parameter. Results of sensitivity analysis describe the nature and extent of the influence of each paramete...
2013 Joint IFSA World Congress and NAFIPS Annual Meeting (IFSA/NAFIPS), 2013
Uncertainty is an inherent characteristic of construction projects. Neglecting uncertainties asso... more Uncertainty is an inherent characteristic of construction projects. Neglecting uncertainties associated with different input parameters in the planning stage could well lead to misleading and unrealistic project schedules. This research presents an algorithm for optimized scheduling of repetitive construction projects under uncertainty. The research utilizes fuzzy set theory to model uncertainties associated with different input parameters. It employs a dynamic programming algorithm that is especially tailored to accept input for different variables, perform all necessary computations and successfully deliver output, all in terms of fuzzy numbers. The algorithm has the ability to identify the optimum crew formation that would yield project least cost or project shortest duration according to the user preferences. A case study is drawn from literature and analyzed to demonstrate the algorithm's capabilities and to allow comparison of results to those generated using previous techniques.
The use of barcode technology has proven its effectiveness in a number of industries such as reta... more The use of barcode technology has proven its effectiveness in a number of industries such as retail and manufacturing. This is due to its ability to assist in organizing, storing, retrieving and making use of huge amount of data in an efficient manner. Although, this technology has been explored by many researchers, it has not been yet fully embraced by the construction industry. This paper highlights the potential use of barcode technology in the construction industry. It focuses mainly on presenting an automated system for tracking and control of engineering deliverables such as drawings, reports and specifications. The system utilizes barcode technology and database management systems (DBMS) for performing its task. The paper briefly describes the various types of barcode labels, scanners and decoders and focuses primarily on presenting a barcode system that is designed to facilitate coding of information pertaining to a wide variety of documents produced in the construction environment. It utilizes 92 alphanumeric characters that is coded in accordance to Code 39 system and stores information related to up to 10,000 documents. The paper also presents a schematic diagram for a database system designed to retrieve a wide variety of information in a multi-project environment. A plan for validating the developed system is also presented.
This paper describes a model designed to facilitate the decision-making process for corridor reha... more This paper describes a model designed to facilitate the decision-making process for corridor rehabilitation of municipal assets. The proposed model comprises four main modules encompassing identification of corridor segments, risk assessment of individual asset networks, and integrated risk assessment to identify critical corridor segments and set priorities for intervention plans. In general, risk assessment requires integration of the criticality of the asset condition and the consequences of failure values to prioritize intervention plans. Each asset network was evaluated with respect to 13 economic, social, and environmental factors using a weighted scoring system. The criticality index of each asset was developed by combining the consequence of failure index with the condition rating index. The integrated risk index for network segments was calculated by integrating the three criticality indices of the individual assets. A case study, from one of the 19 boroughs within the metropolitan area of the City of Montreal in Canada, was used to illustrate the developed modules and their respective functions. The results indicated a strong positive relationship between the integrated risk index and the criticality indices of the three networks. It also shows that the model successfully represents the integrated criticality index for the combined water, sewer, and road segments using their criticality indices as the coefficient of determination R2 was 0.9656. The implementation of the proposed model on the case study enabled condition rating of integrated segments into five main levels of criticality. The developed model is expected to assist municipal engineers and decision makers to prioritize inspections, rehabilitation, and replacement decisions and optimize budget allocation and resource usage.
City managers and elected officials in many municipalities are frequently faced with the challeng... more City managers and elected officials in many municipalities are frequently faced with the challenge to cater for public expectations on one hand and to comply with technical/engineering requirements on the other. This paper presents a four phased level of service driven reliability based methodology for allocation of budget to water mains. This methodology comprises of: (1) development of an Analytical Hierarchy model of LoS; (2) a sub-network criticality model to account for certain quantitative and qualitative characteristics of a given sub-network (3) a sub-network reliability assessment model and 4) a budget allocation model. Combination of the above contradicting requirements, i.e. level of service and network reliability, is expected to assist decision makers in quantifying the required condition improvement to meet service goals and to make more informed decisions on interventions and relayed priorities. To show the robustness of the developed models, a hypothetical case study is developed and analyzed.
This paper provides a comprehensive comparison between two groups of nondeterministic scheduling ... more This paper provides a comprehensive comparison between two groups of nondeterministic scheduling methods : 1) probabilistic and 2) fuzzy set based methods. A numerical example is used to demonstrate the differences between the two groups of methods. The comparison is conducted considering three aspects : 1) theoretical assumptions, 2) data acquisition and computational effort , and 3) scheduling information. The results indicate that the fuzzy network method can overcome some of the limitations associated with PERT and Monte Carlo simulation. The fuzzy network method is capable of providing realistic and useful information to the project team.
There is need to enhance our understanding of the behavior of various infrastructure networks and... more There is need to enhance our understanding of the behavior of various infrastructure networks and their components when subjected to different sets of conditions. This study uses artificial neural networks, to investigate the importance and influence of certain attributes of sewer pipes, upon their structural performance. Data on six parameters related to sewer pipeline including: pipe length, diameter, depth/cover, pipe material, bedding condition, pipe age and closed circuit television based pipe condition rating, were obtained from the municipality of Pierrefonds Quebec. Back propagation and Probabilistic neural network models were developed and validated. These models were used to rank the parameters, in the order of their influence on pipe condition. Sensitivity analysis was carried out to simulate the structural condition of pipe at a range of values of each of the above parameter. Results of sensitivity analysis describe the nature and extent of the influence of each paramete...
2013 Joint IFSA World Congress and NAFIPS Annual Meeting (IFSA/NAFIPS), 2013
Uncertainty is an inherent characteristic of construction projects. Neglecting uncertainties asso... more Uncertainty is an inherent characteristic of construction projects. Neglecting uncertainties associated with different input parameters in the planning stage could well lead to misleading and unrealistic project schedules. This research presents an algorithm for optimized scheduling of repetitive construction projects under uncertainty. The research utilizes fuzzy set theory to model uncertainties associated with different input parameters. It employs a dynamic programming algorithm that is especially tailored to accept input for different variables, perform all necessary computations and successfully deliver output, all in terms of fuzzy numbers. The algorithm has the ability to identify the optimum crew formation that would yield project least cost or project shortest duration according to the user preferences. A case study is drawn from literature and analyzed to demonstrate the algorithm's capabilities and to allow comparison of results to those generated using previous techniques.
The use of barcode technology has proven its effectiveness in a number of industries such as reta... more The use of barcode technology has proven its effectiveness in a number of industries such as retail and manufacturing. This is due to its ability to assist in organizing, storing, retrieving and making use of huge amount of data in an efficient manner. Although, this technology has been explored by many researchers, it has not been yet fully embraced by the construction industry. This paper highlights the potential use of barcode technology in the construction industry. It focuses mainly on presenting an automated system for tracking and control of engineering deliverables such as drawings, reports and specifications. The system utilizes barcode technology and database management systems (DBMS) for performing its task. The paper briefly describes the various types of barcode labels, scanners and decoders and focuses primarily on presenting a barcode system that is designed to facilitate coding of information pertaining to a wide variety of documents produced in the construction environment. It utilizes 92 alphanumeric characters that is coded in accordance to Code 39 system and stores information related to up to 10,000 documents. The paper also presents a schematic diagram for a database system designed to retrieve a wide variety of information in a multi-project environment. A plan for validating the developed system is also presented.
This paper describes a model designed to facilitate the decision-making process for corridor reha... more This paper describes a model designed to facilitate the decision-making process for corridor rehabilitation of municipal assets. The proposed model comprises four main modules encompassing identification of corridor segments, risk assessment of individual asset networks, and integrated risk assessment to identify critical corridor segments and set priorities for intervention plans. In general, risk assessment requires integration of the criticality of the asset condition and the consequences of failure values to prioritize intervention plans. Each asset network was evaluated with respect to 13 economic, social, and environmental factors using a weighted scoring system. The criticality index of each asset was developed by combining the consequence of failure index with the condition rating index. The integrated risk index for network segments was calculated by integrating the three criticality indices of the individual assets. A case study, from one of the 19 boroughs within the metropolitan area of the City of Montreal in Canada, was used to illustrate the developed modules and their respective functions. The results indicated a strong positive relationship between the integrated risk index and the criticality indices of the three networks. It also shows that the model successfully represents the integrated criticality index for the combined water, sewer, and road segments using their criticality indices as the coefficient of determination R2 was 0.9656. The implementation of the proposed model on the case study enabled condition rating of integrated segments into five main levels of criticality. The developed model is expected to assist municipal engineers and decision makers to prioritize inspections, rehabilitation, and replacement decisions and optimize budget allocation and resource usage.
City managers and elected officials in many municipalities are frequently faced with the challeng... more City managers and elected officials in many municipalities are frequently faced with the challenge to cater for public expectations on one hand and to comply with technical/engineering requirements on the other. This paper presents a four phased level of service driven reliability based methodology for allocation of budget to water mains. This methodology comprises of: (1) development of an Analytical Hierarchy model of LoS; (2) a sub-network criticality model to account for certain quantitative and qualitative characteristics of a given sub-network (3) a sub-network reliability assessment model and 4) a budget allocation model. Combination of the above contradicting requirements, i.e. level of service and network reliability, is expected to assist decision makers in quantifying the required condition improvement to meet service goals and to make more informed decisions on interventions and relayed priorities. To show the robustness of the developed models, a hypothetical case study is developed and analyzed.
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Papers by Osama Moselhi