Prachi Sohoni, Abdul Ghaffar, V. Matsagar, K. N. Jha
Abstract Formwork system is a significant constituent and a basic requirement for high-rise cast-in-place reinforced concrete buildings. Usually, the builders are confronted with the decision to choose the safe, optimum number of levels of shores/reshores for a predetermined safety factor and given grade of concrete, giving due consideration to the cost of formwork system. In this study, MATLAB program is developed to calculate the load distribution between the interconnected slabs and levels of shore/reshore of a slab formwork based on a simplified method. This program is further modified by incorporating genetic algorithm for the optimization of cost of construction for high-rise building. The cost of level of shores and reshores per floor is defined as a function of cycle time which directly reflects the increase in the cost of construction. Various combinations of shore and reshore levels with several grades of concrete for various safety factors are checked to minimize the cost of construction. The optimization equation is solved using genetic algorithm considering appropriate constraints to practically ensure feasible solutions. The case of one level of shores and numerous levels of reshores is better than one level of reshores and numerous levels of shores. The result of certain combination of shore and reshore levels is not the same when the level numbers are reversed. A comparative study is carried out to check the optimum cost for various safety factors. The program is useful for the designers to decide the levels of shores and reshores with minimized cost without compromising the safety of construction.
{"title":"Optimization of shoring/reshoring levels in high-rise building construction","authors":"Prachi Sohoni, Abdul Ghaffar, V. Matsagar, K. N. Jha","doi":"10.2478/otmcj-2018-0009","DOIUrl":"https://doi.org/10.2478/otmcj-2018-0009","url":null,"abstract":"Abstract Formwork system is a significant constituent and a basic requirement for high-rise cast-in-place reinforced concrete buildings. Usually, the builders are confronted with the decision to choose the safe, optimum number of levels of shores/reshores for a predetermined safety factor and given grade of concrete, giving due consideration to the cost of formwork system. In this study, MATLAB program is developed to calculate the load distribution between the interconnected slabs and levels of shore/reshore of a slab formwork based on a simplified method. This program is further modified by incorporating genetic algorithm for the optimization of cost of construction for high-rise building. The cost of level of shores and reshores per floor is defined as a function of cycle time which directly reflects the increase in the cost of construction. Various combinations of shore and reshore levels with several grades of concrete for various safety factors are checked to minimize the cost of construction. The optimization equation is solved using genetic algorithm considering appropriate constraints to practically ensure feasible solutions. The case of one level of shores and numerous levels of reshores is better than one level of reshores and numerous levels of shores. The result of certain combination of shore and reshore levels is not the same when the level numbers are reversed. A comparative study is carried out to check the optimum cost for various safety factors. The program is useful for the designers to decide the levels of shores and reshores with minimized cost without compromising the safety of construction.","PeriodicalId":42309,"journal":{"name":"Organization Technology and Management in Construction","volume":"10 1","pages":"1803 - 1826"},"PeriodicalIF":2.1,"publicationDate":"2018-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43380740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The construction industry plays a significant role in the infrastructure development of many countries. Construction projects suffer from a lot of setbacks despite sophistication and advancement in technology and professionalism. This study, therefore, assessed the factors that triggered the emergence of rework and the benefits derived from eliminating such triggers in the Nigerian construction industry. The study adopted a quantitative survey approach in which a structured questionnaire was adopted as the research instrument. Factor analysis using principal component analysis was adopted to determine the factors that triggered the rework and the pattern of relationship that existed amongst the factors; relative importance index (RII) was used to assess the benefits of eliminating rework triggers. The study concluded that the factors that triggered the emergence of rework were omission and planning issues, change issues, funding and communication issues, and poor workers and resource control. Repeat patronage, higher productivity, and reduced delivery time reduced the rework and waste and improved the employee job satisfaction and morale; they were the benefits derived from eliminating rework triggers. It was recommended that there is a need for clarity, effectiveness, and timeliness of instruction and information dissemination amongst project participants and the participation of contractors, subcontractors, and other stakeholders at the design stages to avoid omissions and construction changes.
{"title":"Analysis of rework risk triggers in the Nigerian construction industry","authors":"E. Eze, J. E. Idiake, B. O. Ganiyu","doi":"10.2478/otmcj-2018-0008","DOIUrl":"https://doi.org/10.2478/otmcj-2018-0008","url":null,"abstract":"Abstract The construction industry plays a significant role in the infrastructure development of many countries. Construction projects suffer from a lot of setbacks despite sophistication and advancement in technology and professionalism. This study, therefore, assessed the factors that triggered the emergence of rework and the benefits derived from eliminating such triggers in the Nigerian construction industry. The study adopted a quantitative survey approach in which a structured questionnaire was adopted as the research instrument. Factor analysis using principal component analysis was adopted to determine the factors that triggered the rework and the pattern of relationship that existed amongst the factors; relative importance index (RII) was used to assess the benefits of eliminating rework triggers. The study concluded that the factors that triggered the emergence of rework were omission and planning issues, change issues, funding and communication issues, and poor workers and resource control. Repeat patronage, higher productivity, and reduced delivery time reduced the rework and waste and improved the employee job satisfaction and morale; they were the benefits derived from eliminating rework triggers. It was recommended that there is a need for clarity, effectiveness, and timeliness of instruction and information dissemination amongst project participants and the participation of contractors, subcontractors, and other stakeholders at the design stages to avoid omissions and construction changes.","PeriodicalId":42309,"journal":{"name":"Organization Technology and Management in Construction","volume":"10 1","pages":"1778 - 1793"},"PeriodicalIF":2.1,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49539623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Transferring all or some parts of the engineering activities or supply of goods to third persons or companies is one of the adopted methods that transfer a significant part of the likely risks to the concerned side. Outsourcing activities are followed by many benefits, such as reducing overhead and operational costs, increasing efficiency, reducing risk, and so on; however, if this is not done carefully, not only is no benefit gained, but also new risks are imposed on the organization. Considering that waste of time and cost diversions of projects stem from the selection of inappropriate contractors, risk assessment is important in outsourcing. Using a risk-oriented approach based on software toward outsourcing, the present study aims to identify and rate the factors affecting the selection of contractors and to finally provide a method to evaluate and select the proper way for the selection of contractors. This method is not just based on the lowest price, but it also includes several factors that influence the selection of contractors, which is achieved by applying the Expert Choice software. At first, the most important risk factors in the selection of contractors were identified according to the conducted research. Then, the factors that had the greatest risk potential for achieving the project goals were chosen from among them. The opinions of experts were obtained in the next phase to determine the importance of various factors in the process of contractor selection, which was achieved by the distribution of a questionnaire. Subsequently, the most important factors chosen by the experts were specified, and their relationship with the contractor’s risk management was found.
{"title":"Identification and evaluation of criteria for selecting contractors using a risk management approach","authors":"E. Mousakhani, Shirzad Ranjbar, Taha Ashoori","doi":"10.2478/otmcj-2018-0004","DOIUrl":"https://doi.org/10.2478/otmcj-2018-0004","url":null,"abstract":"Abstract Transferring all or some parts of the engineering activities or supply of goods to third persons or companies is one of the adopted methods that transfer a significant part of the likely risks to the concerned side. Outsourcing activities are followed by many benefits, such as reducing overhead and operational costs, increasing efficiency, reducing risk, and so on; however, if this is not done carefully, not only is no benefit gained, but also new risks are imposed on the organization. Considering that waste of time and cost diversions of projects stem from the selection of inappropriate contractors, risk assessment is important in outsourcing. Using a risk-oriented approach based on software toward outsourcing, the present study aims to identify and rate the factors affecting the selection of contractors and to finally provide a method to evaluate and select the proper way for the selection of contractors. This method is not just based on the lowest price, but it also includes several factors that influence the selection of contractors, which is achieved by applying the Expert Choice software. At first, the most important risk factors in the selection of contractors were identified according to the conducted research. Then, the factors that had the greatest risk potential for achieving the project goals were chosen from among them. The opinions of experts were obtained in the next phase to determine the importance of various factors in the process of contractor selection, which was achieved by the distribution of a questionnaire. Subsequently, the most important factors chosen by the experts were specified, and their relationship with the contractor’s risk management was found.","PeriodicalId":42309,"journal":{"name":"Organization Technology and Management in Construction","volume":"10 1","pages":"1747 - 1760"},"PeriodicalIF":2.1,"publicationDate":"2018-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2478/otmcj-2018-0004","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42068660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Hertogh, J. Bakker, M. J. van der Vlist, A. S. Barneveld
Abstract In the forthcoming decades, many objects in transport infrastructure networks will come to the end of their technical, economical or functional lifespan. The replacement and renovation will require substantial budgets and a timely start to secure the current functionalities. These challenges are a main concern for asset managers. However, the replacement programmes also have the opportunity not only to maintain the currently needed functionalities and quality but also for the timely adaptation of infrastructure networks to changing demands, because these will determine the value of these networks in the future. This will give added value not only to asset managers, but also to users (e.g. increased functionality), enterprises (e.g. new business opportunities), stakeholders (e.g. increase of liveability) and society as a whole (e.g. increased sustainability). Each replacement and renovation is an opportunity to make infrastructure networks more fit for future economic and environmental needs. This means a shift in thinking for asset managers to a broader view. This paper proposes strategies for asset managers to cope with the challenges and opportunities. The traditional approach focuses on the delivery, but the key for the replacement and renovation programme is to focus on the whole life cycle through life cycle management (LCM). From the LCM-approach, four perspectives are presented to strategic decision-making on replacements and renovations: (1) broadening towards a network approach as an opportunity for redesign, (2) developing innovations for increasing requirements and budget restrictions, (3) realizing adaptive networks to cope with future challenges and (4) combining functionalities to increase added value. Ultimately the goal is to maximize value for society.
{"title":"Life cycle management in upgrade and renewal of civil infrastructures","authors":"M. Hertogh, J. Bakker, M. J. van der Vlist, A. S. Barneveld","doi":"10.2478/otmcj-2018-0005","DOIUrl":"https://doi.org/10.2478/otmcj-2018-0005","url":null,"abstract":"Abstract In the forthcoming decades, many objects in transport infrastructure networks will come to the end of their technical, economical or functional lifespan. The replacement and renovation will require substantial budgets and a timely start to secure the current functionalities. These challenges are a main concern for asset managers. However, the replacement programmes also have the opportunity not only to maintain the currently needed functionalities and quality but also for the timely adaptation of infrastructure networks to changing demands, because these will determine the value of these networks in the future. This will give added value not only to asset managers, but also to users (e.g. increased functionality), enterprises (e.g. new business opportunities), stakeholders (e.g. increase of liveability) and society as a whole (e.g. increased sustainability). Each replacement and renovation is an opportunity to make infrastructure networks more fit for future economic and environmental needs. This means a shift in thinking for asset managers to a broader view. This paper proposes strategies for asset managers to cope with the challenges and opportunities. The traditional approach focuses on the delivery, but the key for the replacement and renovation programme is to focus on the whole life cycle through life cycle management (LCM). From the LCM-approach, four perspectives are presented to strategic decision-making on replacements and renovations: (1) broadening towards a network approach as an opportunity for redesign, (2) developing innovations for increasing requirements and budget restrictions, (3) realizing adaptive networks to cope with future challenges and (4) combining functionalities to increase added value. Ultimately the goal is to maximize value for society.","PeriodicalId":42309,"journal":{"name":"Organization Technology and Management in Construction","volume":"10 1","pages":"1735 - 1746"},"PeriodicalIF":2.1,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45068941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Voluntary employee turnover can cause organizations to lose profits and competitiveness. Unexpected employee turnover may also result in project delay and reduction in project quality. It is important to control employee turnover rate and maintain good employees within an organization. This paper investigates the major causes of voluntary employee turnover in engineering industries. Australia, Mainland China, and Taiwan were selected for the investigation. Questionnaires were administered, and structured interviews were conducted. Power spectrum was used for the analysis. It was found that “Good physical working environment”, “Receiving advanced training”, and “Short travel distance between home and work” are the major job-related ideal factors for the Australian, Mainland China, and Taiwan respondents, respectively. However, “Far distance between work and home” and “Dislike the colleague relationships” are found as the major factors for leaving jobs for the Australian/Taiwan and Mainland China respondents, respectively. Recommendations to improve and to control employee turnover rate are also discussed.
{"title":"Power spectral and bispectral study of factors affecting employee turnover","authors":"V. Tam, K. Le","doi":"10.2478/otmcj-2018-0006","DOIUrl":"https://doi.org/10.2478/otmcj-2018-0006","url":null,"abstract":"Abstract Voluntary employee turnover can cause organizations to lose profits and competitiveness. Unexpected employee turnover may also result in project delay and reduction in project quality. It is important to control employee turnover rate and maintain good employees within an organization. This paper investigates the major causes of voluntary employee turnover in engineering industries. Australia, Mainland China, and Taiwan were selected for the investigation. Questionnaires were administered, and structured interviews were conducted. Power spectrum was used for the analysis. It was found that “Good physical working environment”, “Receiving advanced training”, and “Short travel distance between home and work” are the major job-related ideal factors for the Australian, Mainland China, and Taiwan respondents, respectively. However, “Far distance between work and home” and “Dislike the colleague relationships” are found as the major factors for leaving jobs for the Australian/Taiwan and Mainland China respondents, respectively. Recommendations to improve and to control employee turnover rate are also discussed.","PeriodicalId":42309,"journal":{"name":"Organization Technology and Management in Construction","volume":"10 1","pages":"1727 - 1734"},"PeriodicalIF":2.1,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2478/otmcj-2018-0006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"69243198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Sustainable development has become a goal for all countries seeking a balance between social, environmental and economic needs. The principal vision of a sustainable built future is about developing creative designs that utilize energy and materials effectively. However, this vision should consider historic buildings that were built centuries ago. Although many of these buildings are standing in a stable state, they are obsolete and their values are not fully utilized. Towards revitalizing and generating sustainable values of these buildings, adaptive reuse is adopted as a process of modifying, adapting and reusing obsolete buildings with their existing structures to extend their life cycle whilst performing a new function. This is currently practiced worldwide, specifically when a building has a unique architectural character and is in a stable condition. The adaptive reuse of a historic building should have minimal impact on the heritage significance of the building and its setting. This paper aims to investigate the effectiveness of adaptive reuse as an innovative approach for generating sustainable values of historic buildings in developing countries. To achieve this aim, a research strategy is designed to accomplish four objectives: first, literature related to sustainable development, sustainable values, adaptive reuse and developing countries is reviewed; second, two case studies are presented and analysed to investigate the role of adaptive reuse towards increasing the sustainable value of heritage buildings; third, a strategy with its action plan is developed for facilitating adaptive reuse of historic buildings in developing countries and finally, research conclusions are outlined and recommendations useful to professionals concerned with adaptive reuse of historic buildings are proposed.
{"title":"Adaptive reuse: an innovative approach for generating sustainable values for historic buildings in developing countries","authors":"A. Othman, Heba Elsaay","doi":"10.2478/otmcj-2018-0002","DOIUrl":"https://doi.org/10.2478/otmcj-2018-0002","url":null,"abstract":"Abstract Sustainable development has become a goal for all countries seeking a balance between social, environmental and economic needs. The principal vision of a sustainable built future is about developing creative designs that utilize energy and materials effectively. However, this vision should consider historic buildings that were built centuries ago. Although many of these buildings are standing in a stable state, they are obsolete and their values are not fully utilized. Towards revitalizing and generating sustainable values of these buildings, adaptive reuse is adopted as a process of modifying, adapting and reusing obsolete buildings with their existing structures to extend their life cycle whilst performing a new function. This is currently practiced worldwide, specifically when a building has a unique architectural character and is in a stable condition. The adaptive reuse of a historic building should have minimal impact on the heritage significance of the building and its setting. This paper aims to investigate the effectiveness of adaptive reuse as an innovative approach for generating sustainable values of historic buildings in developing countries. To achieve this aim, a research strategy is designed to accomplish four objectives: first, literature related to sustainable development, sustainable values, adaptive reuse and developing countries is reviewed; second, two case studies are presented and analysed to investigate the role of adaptive reuse towards increasing the sustainable value of heritage buildings; third, a strategy with its action plan is developed for facilitating adaptive reuse of historic buildings in developing countries and finally, research conclusions are outlined and recommendations useful to professionals concerned with adaptive reuse of historic buildings are proposed.","PeriodicalId":42309,"journal":{"name":"Organization Technology and Management in Construction","volume":"10 1","pages":"1704 - 1718"},"PeriodicalIF":2.1,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47988010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Labour-only procurement system is gaining fast popularity among construction clients who want to make savings by procuring materials themselves, leaving the contractor to provide only the labour needed. This study, therefore, appraised this procurement system by assessing its cost performance, its suitability, construction participant’s willingness to use it for subsequent projects and its merits and demerits. Using a survey design approach through the use of questionnaire and a pro forma, data were gathered from a total of 98 construction professionals and contractors who have been involved in the use of this procurement system. Analyses of data were done using percentage, mean item score, Mann–Whitney U test and paired samples t-test. The study revealed that this procurement system is best for procuring residential buildings and minor alteration works. Construction participants who have used this system before are willing to still use it for subsequent works, as it delivers projects within budget and discourages short-changing of specifications and standard by contractors. However, the need for the time commitment and reduction in contractor’s profit are its major disadvantages. For its cost performance, an overall cost saving of about 2% was discovered for the assessed 32 projects. The findings of this study will be beneficial to various interest groups such as clients and estate developers in selecting the right procurement option to use.
{"title":"Appraising the use of labour-only procurement system for building construction in Nigeria","authors":"O. Akinkunmi, D. Aghimien, O. Awodele","doi":"10.2478/otmcj-2018-0003","DOIUrl":"https://doi.org/10.2478/otmcj-2018-0003","url":null,"abstract":"Abstract Labour-only procurement system is gaining fast popularity among construction clients who want to make savings by procuring materials themselves, leaving the contractor to provide only the labour needed. This study, therefore, appraised this procurement system by assessing its cost performance, its suitability, construction participant’s willingness to use it for subsequent projects and its merits and demerits. Using a survey design approach through the use of questionnaire and a pro forma, data were gathered from a total of 98 construction professionals and contractors who have been involved in the use of this procurement system. Analyses of data were done using percentage, mean item score, Mann–Whitney U test and paired samples t-test. The study revealed that this procurement system is best for procuring residential buildings and minor alteration works. Construction participants who have used this system before are willing to still use it for subsequent works, as it delivers projects within budget and discourages short-changing of specifications and standard by contractors. However, the need for the time commitment and reduction in contractor’s profit are its major disadvantages. For its cost performance, an overall cost saving of about 2% was discovered for the assessed 32 projects. The findings of this study will be beneficial to various interest groups such as clients and estate developers in selecting the right procurement option to use.","PeriodicalId":42309,"journal":{"name":"Organization Technology and Management in Construction","volume":"10 1","pages":"1719 - 1726"},"PeriodicalIF":2.1,"publicationDate":"2018-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41963741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The dynamic construction site layout planning (DCSLP) problem refers to the efficient placement and relocation of temporary construction facilities within a dynamically changing construction site environment considering the characteristics of facilities and work interrelationships, the shape and topography of the construction site, and the time-varying project needs. A multi-objective dynamic optimization model is developed for this problem that considers construction and relocation costs of facilities, transportation costs of resources moving from one facility to another or to workplaces, as well as safety and environmental considerations resulting from facilities’ operations and interconnections. The latter considerations are taken into account in the form of preferences or constraints regarding the proximity or remoteness of particular facilities to other facilities or work areas. The analysis of multiple project phases and the dynamic facility relocation from phase to phase highly increases the problem size, which, even in its static form, falls within the NP (for Nondeterministic Polynomial time)- hard class of combinatorial optimization problems. For this reason, a genetic algorithm has been implemented for the solution due to its capability to robustly search within a large solution space. Several case studies and operational scenarios have been implemented through the Palisade’s Evolver software for model testing and evaluation. The results indicate satisfactory model response to time-varying input data in terms of solution quality and computation time. The model can provide decision support to site managers, allowing them to examine alternative scenarios and fine-tune optimal solutions according to their experience by introducing desirable preferences or constraints in the decision process.
{"title":"Genetic algorithm optimization for dynamic construction site layout planning","authors":"M. Panagiotis, P. Athanasios","doi":"10.1515/OTMCJ-2016-0026","DOIUrl":"https://doi.org/10.1515/OTMCJ-2016-0026","url":null,"abstract":"The dynamic construction site layout planning (DCSLP) problem refers to the efficient placement and relocation of temporary construction facilities within a dynamically changing construction site environment considering the characteristics of facilities and work interrelationships, the shape and topography of the construction site, and the time-varying project needs. A multi-objective dynamic optimization model is developed for this problem that considers construction and relocation costs of facilities, transportation costs of resources moving from one facility to another or to workplaces, as well as safety and environmental considerations resulting from facilities’ operations and interconnections. The latter considerations are taken into account in the form of preferences or constraints regarding the proximity or remoteness of particular facilities to other facilities or work areas. The analysis of multiple project phases and the dynamic facility relocation from phase to phase highly increases the problem size, which, even in its static form, falls within the NP (for Nondeterministic Polynomial time)- hard class of combinatorial optimization problems. For this reason, a genetic algorithm has been implemented for the solution due to its capability to robustly search within a large solution space. Several case studies and operational scenarios have been implemented through the Palisade’s Evolver software for model testing and evaluation. The results indicate satisfactory model response to time-varying input data in terms of solution quality and computation time. The model can provide decision support to site managers, allowing them to examine alternative scenarios and fine-tune optimal solutions according to their experience by introducing desirable preferences or constraints in the decision process.","PeriodicalId":42309,"journal":{"name":"Organization Technology and Management in Construction","volume":"10 1","pages":"1655-1664"},"PeriodicalIF":2.1,"publicationDate":"2018-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/OTMCJ-2016-0026","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67253623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The construction industry did not just evolve on its own. It is a product of the conscious efforts of several individuals called construction workers. In Nigeria, it is a large employer of the population, skilled, unskilled, and professional. However, the Nigerian construction industry, similar to other industries, is currently in a phase of economic reform. This is largely attributed to the present economic situation. The current recession condition of the Nigerian economy has an adverse effect on the income of the citizenry. This implies that other sources of income alongside the basic firsthand means of income generation have to be sourced. This dilemma is more prominent among women. Considering the construction industry, professional female construction workers have been observed to join the league of those involved in ancillary income generation occupations. It is worth noting, however, that there are few professional female construction workers in the first place. This paper addresses whether this drift is a diversification or deviation of Nigerian professional female construction workers to vocational occupations, by a rigorous review of related literature. The result shows that this new trend among professional female construction workers is a welcome one if it is diversification because this will improve the productiveness of the individual involved and, in the long run, better the economy. On the other hand, this work finds that if these vocational occupations make professional female construction workers leave their construction field totally or almost totally, then there is a threat to female population in the construction industry. However, diversification is encouraged.
{"title":"Nigerian Professional Female Construction Workers in Vocational Occupations: Diversification or Deviation?","authors":"T. B. Odubiyi","doi":"10.2478/otmcj-2018-0001","DOIUrl":"https://doi.org/10.2478/otmcj-2018-0001","url":null,"abstract":"Abstract The construction industry did not just evolve on its own. It is a product of the conscious efforts of several individuals called construction workers. In Nigeria, it is a large employer of the population, skilled, unskilled, and professional. However, the Nigerian construction industry, similar to other industries, is currently in a phase of economic reform. This is largely attributed to the present economic situation. The current recession condition of the Nigerian economy has an adverse effect on the income of the citizenry. This implies that other sources of income alongside the basic firsthand means of income generation have to be sourced. This dilemma is more prominent among women. Considering the construction industry, professional female construction workers have been observed to join the league of those involved in ancillary income generation occupations. It is worth noting, however, that there are few professional female construction workers in the first place. This paper addresses whether this drift is a diversification or deviation of Nigerian professional female construction workers to vocational occupations, by a rigorous review of related literature. The result shows that this new trend among professional female construction workers is a welcome one if it is diversification because this will improve the productiveness of the individual involved and, in the long run, better the economy. On the other hand, this work finds that if these vocational occupations make professional female construction workers leave their construction field totally or almost totally, then there is a threat to female population in the construction industry. However, diversification is encouraged.","PeriodicalId":42309,"journal":{"name":"Organization Technology and Management in Construction","volume":"10 1","pages":"1696 - 1703"},"PeriodicalIF":2.1,"publicationDate":"2018-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48069856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract In general, every project should have indicators that monitor compliance with established goals. In construction projects, there are a large number of indicators proposed by many researchers; however, an analysis of the state of the art shows a frequent confusion between Result, Process and Leading Indicators. This paper, which is an extended version of the paper submitted by the same authors at the Creative Construction Conference 2017 and published in Procedia Engineering (DOI: 10.1016/j.proeng.2017.07.230), presents a proposal of these three types of indicators for the design, supply and assembly phases of housing projects. Thus, all project stakeholders can have a control panel that will monitor if an indicator exceeds the limits, thereby allowing taking corrective actions in a timely and effective manner.
{"title":"Control panel and indicators for production control in building projects","authors":"P. Orihuela, Santiago Pacheco, J. Orihuela","doi":"10.1515/otmcj-2016-0027","DOIUrl":"https://doi.org/10.1515/otmcj-2016-0027","url":null,"abstract":"Abstract In general, every project should have indicators that monitor compliance with established goals. In construction projects, there are a large number of indicators proposed by many researchers; however, an analysis of the state of the art shows a frequent confusion between Result, Process and Leading Indicators. This paper, which is an extended version of the paper submitted by the same authors at the Creative Construction Conference 2017 and published in Procedia Engineering (DOI: 10.1016/j.proeng.2017.07.230), presents a proposal of these three types of indicators for the design, supply and assembly phases of housing projects. Thus, all project stakeholders can have a control panel that will monitor if an indicator exceeds the limits, thereby allowing taking corrective actions in a timely and effective manner.","PeriodicalId":42309,"journal":{"name":"Organization Technology and Management in Construction","volume":"10 1","pages":"1665 - 1673"},"PeriodicalIF":2.1,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48743353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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