Sompong Sirisoponsilp | Chulalongkorn University (original) (raw)
Papers by Sompong Sirisoponsilp
American Journal of Engineering and Applied Sciences, Apr 1, 2010
Problem statement: Commodity Flow Survey (CFS) was launched to collect comprehensive freight flow... more Problem statement: Commodity Flow Survey (CFS) was launched to collect comprehensive freight flow data throughout the kingdom of Thailand. The survey's database is the most complete collection of commodity flow data in Thailand. The need to reveal interregional freight characteristics using available data from the CFS led to the objectives of this research. Approach: An origin destination matrix based on province was calibrated using a flexible Box-Cox function form. It used maximum likelihood and the backward method for calibration and Root Mean Square Error (RMSE) and Mean Relative Error (MRE) to verify the model's performance. Independent variables were classified into three groups: origin variable, destination variable and geographic variable. The origin variable represented the behavior of the trip as generated at the place of origin. Some consumption occurred at the origin. The employment and the average plant size variables were selected for potential productivity while personal income per capita and total populations were included to explain consumption behavior at the origin. Personal income per capita and total populations were selected for destination variables which act as proxy for final demand at the destination. The third category, distance, was the most conventional friction variable for geographical variables. Results: The calibrated model revealed that origin income, origin average plant size and origin population performed poorly. Therefore these variables were eliminated. The best developed model included four strongly significant variables at a 5% level: origin employment, destination population, destination income per capita and distance. Conclusion: The results showed that the selected variables and the Box-Cox functional form were successful in explaining behavior of interregional freight transportation in Thailand. The developed model was the first interregional freight transportation model to be calibrated against Thailand commodity flow survey data.
This research carries out attitude toward truck driver profession surveys with the objective to d... more This research carries out attitude toward truck driver profession surveys with the objective to determine the factors influencing the shortage of truck drivers in Industry-level and Firm-level. The study divides survey samples into two groups. The first group represents the draftees (Industry-level) who represent the potential pool of future truck drivers. A sample of 150 men is solicited to express their attitude towards the truck driver profession. The second group of sample consists of 93 truck drivers (Firm-level) who are asked to share their intention to stay in the profession and in the current job. The questionnaire adopted in the survey breaks up the attitude toward truck driver profession into a number of dimensions, each consisting of several attitude items. The survey data are first analyzed to compute a number of descriptive statistics of the survey responses. The multiple regression analysis is finally employed to determine the cause-and-effect relationship that will shed the light on the key factors influencing the intention to enter, to stay in the profession and in the current job. Key findings of the analyses are: 1. The draftees are found to be highly concerned about the career path opportunities in deciding whether or not to seek a career in trucking driving. 2. The intention to stay in the career of existing truck drivers is highly influenced by the career path opportunities and job security, job characteristics, relationship with colleagues, the degree of pride in the career. 3. The intention to stay in the current workplace is highly affected by job characteristics, relationship with customers, the degree of pride in the work, and the reputation of the workplace.
A state-of-the-art study has been conducted to investigate the strategies used by state highway a... more A state-of-the-art study has been conducted to investigate the strategies used by state highway agencies to restrict trucks from certain lanes on urban freeways, and the impacts of such restrictions on traffic operation and safety. The study was based on a review of literature pertaining to truck lane restrictions and a survey of state highway agencies about their experience with such restrictions. The information obtained from both sources was used to assess the objectives and effectiveness of the restrictions, current restriction methods, enforcement practices, and procedures for evaluating the restrictions. It was found that although truck lane restrictions have been imposed in a number of states for many years, the effects on traffic operation and safety are still not well known and their cost effectiveness is still in doubt until some comprehensive studies are made. The study also provides suggestions to improve the evaluation of operational and safety impacts of current lane r...
A state-of-the-art study has been conducted to investigate the strategies used by state highway a... more A state-of-the-art study has been conducted to investigate the strategies used by state highway agencies to restrict trucks from certain lanes on urban freeways, and the impacts of such restrictions on traffic operation and safety. The study was based on a review of literature pertaining to truck lane restrictions and a survey of state highway agencies about their experience with such restrictions. The information obtained from both sources was used to assess the objectives and effectiveness of the restrictions, current restriction methods, enforcement practices, and procedures for evaluating the restrictions. It was found that although truck lane restrictions have been imposed in a number of states for many years, the effects on traffic operation and safety are still not well known and their cost effectiveness is still in doubt until some comprehensive studies are made. The study also provides suggestions to improve the evaluation of operational and safety impacts of current lane r...
The study develops a methodology for forecasting future truck volumes. The proposed methodology p... more The study develops a methodology for forecasting future truck volumes. The proposed methodology projects truck traffic on a link-by-link basis and does not account for the interrelation among links. The study determines the relations between truck volumes and selected explanatory variables observed at certain locations and then develops a forecasting process which applies the estimated relationship between truck traffic and selected explanatory variables to forecast future truck traffic. Recommendations are also provided for improving and updating the proposed forecasting methodology.
continuous support throughout the thesis since starting creating an idea, raise the proposal, imp... more continuous support throughout the thesis since starting creating an idea, raise the proposal, implement the data and finalized the result. He always promptly listened and gave me advice. He is expert in inventory management and has many experience background knowledge in different kind of products in inventory management. He guided me to have a right way thinking concept reasonably and how to approach a research problem. I also thank my minor advisor and being committee at the same time, assistant professor Dr.Paveena Chaowalitwong who gave me advice for the solution in case mathematical model is inadequate. She advised me a clearer picture in the fact of inventory problem. She is also the expert lecturer in inventory management. Another special thank is to Dr.Thantat Mokkamakkul who is the chairman of thesis committee. Without this approval and support, my thesis might not be able to complete successfully. Besides my advisors and committees, I would like to thank my my family: my mother for being my inspiration in Master Degree Study, my brother in giving me a comment and provided some guidance, my husband who always being my side and helped me to find out mathematical models. I hope that my thesis would be useful for anyone who is interested in inventory management. Last but not least, my thesis might not be successful if I haven't got a support and encouragement from my classmates; Jeab,
Mass Customization has been perceived as a concept playing a crucial role in the delivery managem... more Mass Customization has been perceived as a concept playing a crucial role in the delivery management of textile products according to fashion trends. At present, the production purposes, which aim at serving customers’ needs, have completely changed due to the variety of demands, while the number of lot size orders is dramatically decreasing, causing a need to reduce delivery leadtime. Besides, there are also other demands, having changed. As opposite to the production systems in textile industries, the emphasis is still on Mass Production, which is considered as inflexible in terms of manufacturing process and technology management. This article, therefore, aims at proposing a tool that helps assess the implementation level of Mass Customization employed in textile industries, depending on three major factors: 1) Customer’s need, 2) Manufacturer’s readiness, and 3) Supplier’s readiness. Each factor affecting the readiness of Mass Customization Implementation was obtained from exploratory research, using focus group and in-depth interview. The implementation of Mass Customization is divided into three levels, from levels one to three. The significance of this assessment can be used to consider how Mass Customization is effectively employed in particular textile industries.
International Journal of Physical Distribution & Materials Management, 1988
An integrated model for distribution network design is proposed which explicitly represents the r... more An integrated model for distribution network design is proposed which explicitly represents the required level of customer service.
This paper presents a framework, aiming to develop the mass customization for textile and apparel... more This paper presents a framework, aiming to develop the mass customization for textile and apparel industries in Thailand. The developed model as presented is the relationship of the connection pertaining to customers' needs at industrial levels, most of which are Original Design Manufacturer (OEM), a type of textile and apparel business. The outstanding of OEM is the presentation of newly created designs to customers with a variety of products. Importantly, in order to gain such effective production management, an appropriate administrative system with high flexibility, efficient production (Small Lot Size), and punctual delivery is crucially required. In relation to the framework for mass customization development, it concerns three main related involvements: customers, OEM industries, and suppliers, all of which will be assessed so as to be promptly employed in such firms manufacturing products in accordance with the productive systems of mass customization model.The conceptual from mass customization systems will facilitate the management in terms of the production designing in factories, aiming at clustering which is complex to the creation of platform from common parts, leading to the development of a variety of goods by the process of product family.
Maritime Policy & Management, 2002
ABSTRACT This paper examines the potential of developing coastal ports and channels along the Sou... more ABSTRACT This paper examines the potential of developing coastal ports and channels along the Southern coast on the Gulf of Thailand. There were 18 channels included in the study area, ranging from Ban Don Channel to Pattani Channel. The study approach was based on the analysis of the data on cargo movement to and from the study area by coastal shipping and truck, in terms of quantity and types of cargo. The study found that there are three potential areas to be developed for coastal shipping in Thailand (along the southern part on the Gulf of Thailand), namely Songkhla (Songkhla channel), Surat Thani (Ban Don and/or Ta Thong) and Nakhon Sri Thammarat (Sichon and/or Pak Phanang). This paper, however, suggests that further study on the technical part for support of the precise channels to be developed is needed.
Abstract: Problem statement: Pricing is one of the fundamental management decisions required by a... more Abstract: Problem statement: Pricing is one of the fundamental management decisions required by a truckload carrier. Traditional pricing based on an average all relevant costs including fixed and variable costs is not capable of providing adequate margins that prevent losses during operation uncertainties inherent in truckload operation including demand variability and variation in service times. Approach: This study utilizes Conditional Value at Risk (CVaR) as a measure of risk with significant advantage over Value at Risk (VaR), to full truckload pricing when conditions are unpredictable. It criterion focuses on the tail of the loss distribution and provides a measure of the expected loss exceeding Value-at-Risk. Therefore, it was applied to control the maximum loss or the minimum gain within a specified tolerance level to enable more flexible full truckload pricing. A simulation model is developed to capture the stochastic patterns inherent in the operation of full truckload netw...
Abstract: Problem statement: Commodity Flow Survey (CFS) was launched to collect comprehensive fr... more Abstract: Problem statement: Commodity Flow Survey (CFS) was launched to collect comprehensive freight flow data throughout the kingdom of Thailand. The survey’s database is the most complete collection of commodity flow data in Thailand. The need to reveal interregional freight characteristics using available data from the CFS led to the objectives of this research. Approach: An origin destination matrix based on province was calibrated using a flexible Box-Cox function form. It used maximum likelihood and the backward method for calibration and Root Mean Square Error (RMSE) and Mean Relative Error (MRE) to verify the model’s performance. Independent variables were classified into three groups: origin variable, destination variable and geographic variable. The origin variable represented the behavior of the trip as generated at the place of origin. Some consumption occurred at the origin. The employment and the average plant size variables were selected for potential productivity w...
The research attempts to explore the relative importance of service attributes as perceived by sh... more The research attempts to explore the relative importance of service attributes as perceived by shippers in selecting motor carriers. The study focuses on the delivery of automotive parts and consumer goods and involves three stages of survey. The first stage survey is conducted to develop an initial list of important service features. In the second stage survey, shippers are asked to indicate the degree of perceived importance and satisfaction associated with each service feature in the list. The observed scores are analyzed to identify a small number of service features that need carriers' immediate attention. The third stage survey applies the conjoint analysis to derive relative importance of these critical attributes by investigating shippers' stated choices in a number of binary choice settings. The findings via both direct questioning and conjoint analysis techniques agree that "reliability of on-time delivery" is perceived as the most important decision dete...
WMS Journal of Management, 2014
This research carries out attitude toward truck driver profession surveys with the objective to d... more This research carries out attitude toward truck driver profession surveys with the objective to determine the factors influencing the shortage of truck drivers in Industry-level and Firm-level. The study divides survey samples into two groups. The first group represents the draftees (Industry-level) who represent the potential pool of future truck drivers. A sample of 150 men is solicited to express their attitude towards the truck driver profession. The second group of sample consists of 93 truck drivers (Firm-level) who are asked to share their intention to stay in the profession and in the current job. The questionnaire adopted in the survey breaks up the attitude toward truck driver profession into a number of dimensions, each consisting of several attitude items. The survey data are first analyzed to compute a number of descriptive statistics of the survey responses. The multiple regression analysis is finally employed to determine the cause-and-effect relationship that will sh...
ABSTRACT Thesis (Ph. D.)--University of Maryland at College Park, 1989. Includes bibliographical ... more ABSTRACT Thesis (Ph. D.)--University of Maryland at College Park, 1989. Includes bibliographical references. Microfiche. s
American Journal of Engineering and Applied Sciences, Apr 1, 2010
Problem statement: Commodity Flow Survey (CFS) was launched to collect comprehensive freight flow... more Problem statement: Commodity Flow Survey (CFS) was launched to collect comprehensive freight flow data throughout the kingdom of Thailand. The survey's database is the most complete collection of commodity flow data in Thailand. The need to reveal interregional freight characteristics using available data from the CFS led to the objectives of this research. Approach: An origin destination matrix based on province was calibrated using a flexible Box-Cox function form. It used maximum likelihood and the backward method for calibration and Root Mean Square Error (RMSE) and Mean Relative Error (MRE) to verify the model's performance. Independent variables were classified into three groups: origin variable, destination variable and geographic variable. The origin variable represented the behavior of the trip as generated at the place of origin. Some consumption occurred at the origin. The employment and the average plant size variables were selected for potential productivity while personal income per capita and total populations were included to explain consumption behavior at the origin. Personal income per capita and total populations were selected for destination variables which act as proxy for final demand at the destination. The third category, distance, was the most conventional friction variable for geographical variables. Results: The calibrated model revealed that origin income, origin average plant size and origin population performed poorly. Therefore these variables were eliminated. The best developed model included four strongly significant variables at a 5% level: origin employment, destination population, destination income per capita and distance. Conclusion: The results showed that the selected variables and the Box-Cox functional form were successful in explaining behavior of interregional freight transportation in Thailand. The developed model was the first interregional freight transportation model to be calibrated against Thailand commodity flow survey data.
This research carries out attitude toward truck driver profession surveys with the objective to d... more This research carries out attitude toward truck driver profession surveys with the objective to determine the factors influencing the shortage of truck drivers in Industry-level and Firm-level. The study divides survey samples into two groups. The first group represents the draftees (Industry-level) who represent the potential pool of future truck drivers. A sample of 150 men is solicited to express their attitude towards the truck driver profession. The second group of sample consists of 93 truck drivers (Firm-level) who are asked to share their intention to stay in the profession and in the current job. The questionnaire adopted in the survey breaks up the attitude toward truck driver profession into a number of dimensions, each consisting of several attitude items. The survey data are first analyzed to compute a number of descriptive statistics of the survey responses. The multiple regression analysis is finally employed to determine the cause-and-effect relationship that will shed the light on the key factors influencing the intention to enter, to stay in the profession and in the current job. Key findings of the analyses are: 1. The draftees are found to be highly concerned about the career path opportunities in deciding whether or not to seek a career in trucking driving. 2. The intention to stay in the career of existing truck drivers is highly influenced by the career path opportunities and job security, job characteristics, relationship with colleagues, the degree of pride in the career. 3. The intention to stay in the current workplace is highly affected by job characteristics, relationship with customers, the degree of pride in the work, and the reputation of the workplace.
A state-of-the-art study has been conducted to investigate the strategies used by state highway a... more A state-of-the-art study has been conducted to investigate the strategies used by state highway agencies to restrict trucks from certain lanes on urban freeways, and the impacts of such restrictions on traffic operation and safety. The study was based on a review of literature pertaining to truck lane restrictions and a survey of state highway agencies about their experience with such restrictions. The information obtained from both sources was used to assess the objectives and effectiveness of the restrictions, current restriction methods, enforcement practices, and procedures for evaluating the restrictions. It was found that although truck lane restrictions have been imposed in a number of states for many years, the effects on traffic operation and safety are still not well known and their cost effectiveness is still in doubt until some comprehensive studies are made. The study also provides suggestions to improve the evaluation of operational and safety impacts of current lane r...
A state-of-the-art study has been conducted to investigate the strategies used by state highway a... more A state-of-the-art study has been conducted to investigate the strategies used by state highway agencies to restrict trucks from certain lanes on urban freeways, and the impacts of such restrictions on traffic operation and safety. The study was based on a review of literature pertaining to truck lane restrictions and a survey of state highway agencies about their experience with such restrictions. The information obtained from both sources was used to assess the objectives and effectiveness of the restrictions, current restriction methods, enforcement practices, and procedures for evaluating the restrictions. It was found that although truck lane restrictions have been imposed in a number of states for many years, the effects on traffic operation and safety are still not well known and their cost effectiveness is still in doubt until some comprehensive studies are made. The study also provides suggestions to improve the evaluation of operational and safety impacts of current lane r...
The study develops a methodology for forecasting future truck volumes. The proposed methodology p... more The study develops a methodology for forecasting future truck volumes. The proposed methodology projects truck traffic on a link-by-link basis and does not account for the interrelation among links. The study determines the relations between truck volumes and selected explanatory variables observed at certain locations and then develops a forecasting process which applies the estimated relationship between truck traffic and selected explanatory variables to forecast future truck traffic. Recommendations are also provided for improving and updating the proposed forecasting methodology.
continuous support throughout the thesis since starting creating an idea, raise the proposal, imp... more continuous support throughout the thesis since starting creating an idea, raise the proposal, implement the data and finalized the result. He always promptly listened and gave me advice. He is expert in inventory management and has many experience background knowledge in different kind of products in inventory management. He guided me to have a right way thinking concept reasonably and how to approach a research problem. I also thank my minor advisor and being committee at the same time, assistant professor Dr.Paveena Chaowalitwong who gave me advice for the solution in case mathematical model is inadequate. She advised me a clearer picture in the fact of inventory problem. She is also the expert lecturer in inventory management. Another special thank is to Dr.Thantat Mokkamakkul who is the chairman of thesis committee. Without this approval and support, my thesis might not be able to complete successfully. Besides my advisors and committees, I would like to thank my my family: my mother for being my inspiration in Master Degree Study, my brother in giving me a comment and provided some guidance, my husband who always being my side and helped me to find out mathematical models. I hope that my thesis would be useful for anyone who is interested in inventory management. Last but not least, my thesis might not be successful if I haven't got a support and encouragement from my classmates; Jeab,
Mass Customization has been perceived as a concept playing a crucial role in the delivery managem... more Mass Customization has been perceived as a concept playing a crucial role in the delivery management of textile products according to fashion trends. At present, the production purposes, which aim at serving customers’ needs, have completely changed due to the variety of demands, while the number of lot size orders is dramatically decreasing, causing a need to reduce delivery leadtime. Besides, there are also other demands, having changed. As opposite to the production systems in textile industries, the emphasis is still on Mass Production, which is considered as inflexible in terms of manufacturing process and technology management. This article, therefore, aims at proposing a tool that helps assess the implementation level of Mass Customization employed in textile industries, depending on three major factors: 1) Customer’s need, 2) Manufacturer’s readiness, and 3) Supplier’s readiness. Each factor affecting the readiness of Mass Customization Implementation was obtained from exploratory research, using focus group and in-depth interview. The implementation of Mass Customization is divided into three levels, from levels one to three. The significance of this assessment can be used to consider how Mass Customization is effectively employed in particular textile industries.
International Journal of Physical Distribution & Materials Management, 1988
An integrated model for distribution network design is proposed which explicitly represents the r... more An integrated model for distribution network design is proposed which explicitly represents the required level of customer service.
This paper presents a framework, aiming to develop the mass customization for textile and apparel... more This paper presents a framework, aiming to develop the mass customization for textile and apparel industries in Thailand. The developed model as presented is the relationship of the connection pertaining to customers' needs at industrial levels, most of which are Original Design Manufacturer (OEM), a type of textile and apparel business. The outstanding of OEM is the presentation of newly created designs to customers with a variety of products. Importantly, in order to gain such effective production management, an appropriate administrative system with high flexibility, efficient production (Small Lot Size), and punctual delivery is crucially required. In relation to the framework for mass customization development, it concerns three main related involvements: customers, OEM industries, and suppliers, all of which will be assessed so as to be promptly employed in such firms manufacturing products in accordance with the productive systems of mass customization model.The conceptual from mass customization systems will facilitate the management in terms of the production designing in factories, aiming at clustering which is complex to the creation of platform from common parts, leading to the development of a variety of goods by the process of product family.
Maritime Policy & Management, 2002
ABSTRACT This paper examines the potential of developing coastal ports and channels along the Sou... more ABSTRACT This paper examines the potential of developing coastal ports and channels along the Southern coast on the Gulf of Thailand. There were 18 channels included in the study area, ranging from Ban Don Channel to Pattani Channel. The study approach was based on the analysis of the data on cargo movement to and from the study area by coastal shipping and truck, in terms of quantity and types of cargo. The study found that there are three potential areas to be developed for coastal shipping in Thailand (along the southern part on the Gulf of Thailand), namely Songkhla (Songkhla channel), Surat Thani (Ban Don and/or Ta Thong) and Nakhon Sri Thammarat (Sichon and/or Pak Phanang). This paper, however, suggests that further study on the technical part for support of the precise channels to be developed is needed.
Abstract: Problem statement: Pricing is one of the fundamental management decisions required by a... more Abstract: Problem statement: Pricing is one of the fundamental management decisions required by a truckload carrier. Traditional pricing based on an average all relevant costs including fixed and variable costs is not capable of providing adequate margins that prevent losses during operation uncertainties inherent in truckload operation including demand variability and variation in service times. Approach: This study utilizes Conditional Value at Risk (CVaR) as a measure of risk with significant advantage over Value at Risk (VaR), to full truckload pricing when conditions are unpredictable. It criterion focuses on the tail of the loss distribution and provides a measure of the expected loss exceeding Value-at-Risk. Therefore, it was applied to control the maximum loss or the minimum gain within a specified tolerance level to enable more flexible full truckload pricing. A simulation model is developed to capture the stochastic patterns inherent in the operation of full truckload netw...
Abstract: Problem statement: Commodity Flow Survey (CFS) was launched to collect comprehensive fr... more Abstract: Problem statement: Commodity Flow Survey (CFS) was launched to collect comprehensive freight flow data throughout the kingdom of Thailand. The survey’s database is the most complete collection of commodity flow data in Thailand. The need to reveal interregional freight characteristics using available data from the CFS led to the objectives of this research. Approach: An origin destination matrix based on province was calibrated using a flexible Box-Cox function form. It used maximum likelihood and the backward method for calibration and Root Mean Square Error (RMSE) and Mean Relative Error (MRE) to verify the model’s performance. Independent variables were classified into three groups: origin variable, destination variable and geographic variable. The origin variable represented the behavior of the trip as generated at the place of origin. Some consumption occurred at the origin. The employment and the average plant size variables were selected for potential productivity w...
The research attempts to explore the relative importance of service attributes as perceived by sh... more The research attempts to explore the relative importance of service attributes as perceived by shippers in selecting motor carriers. The study focuses on the delivery of automotive parts and consumer goods and involves three stages of survey. The first stage survey is conducted to develop an initial list of important service features. In the second stage survey, shippers are asked to indicate the degree of perceived importance and satisfaction associated with each service feature in the list. The observed scores are analyzed to identify a small number of service features that need carriers' immediate attention. The third stage survey applies the conjoint analysis to derive relative importance of these critical attributes by investigating shippers' stated choices in a number of binary choice settings. The findings via both direct questioning and conjoint analysis techniques agree that "reliability of on-time delivery" is perceived as the most important decision dete...
WMS Journal of Management, 2014
This research carries out attitude toward truck driver profession surveys with the objective to d... more This research carries out attitude toward truck driver profession surveys with the objective to determine the factors influencing the shortage of truck drivers in Industry-level and Firm-level. The study divides survey samples into two groups. The first group represents the draftees (Industry-level) who represent the potential pool of future truck drivers. A sample of 150 men is solicited to express their attitude towards the truck driver profession. The second group of sample consists of 93 truck drivers (Firm-level) who are asked to share their intention to stay in the profession and in the current job. The questionnaire adopted in the survey breaks up the attitude toward truck driver profession into a number of dimensions, each consisting of several attitude items. The survey data are first analyzed to compute a number of descriptive statistics of the survey responses. The multiple regression analysis is finally employed to determine the cause-and-effect relationship that will sh...
ABSTRACT Thesis (Ph. D.)--University of Maryland at College Park, 1989. Includes bibliographical ... more ABSTRACT Thesis (Ph. D.)--University of Maryland at College Park, 1989. Includes bibliographical references. Microfiche. s