Model for economic replacement time of mining production rigs including redundant rig costs

2015 ◽  
Vol 21 (2) ◽  
pp. 207-226 ◽  
Author(s):  
Hussan Saed Al-Chalabi ◽  
Jan Lundberg ◽  
Majid Al-Gburi ◽  
Alireza Ahmadi ◽  
Behzad Ghodrati
Keyword(s):  
Regression Analysis ◽  
Mining Industry ◽  
Content Type ◽  
Total Cost ◽  
Effect Regression ◽  
Negative Effect ◽  
Optimisation Model ◽  
Artificial Neural Network Ann ◽  
Drilling Rigs ◽  
Replacement Time

Purpose – The purpose of this paper is to present a practical model to determine the economic replacement time (ERT) of production machines. The objective is to minimise the total cost of capital equipment, where total cost includes acquisition, operating, maintenance costs and costs related to the machine’s downtime. The costs related to the machine’s downtime are represented by the costs of using a redundant machine. Design/methodology/approach – In total, four years of cost data are collected. Data are analysed, practical optimisation model is developed and regression analysis is done to estimate the drilling rigs ERT. The artificial neural network (ANN) technique is used to identify the effect of factors influencing the ERT of the drilling rigs. Findings – The results show that the redundant rig cost has the largest impact on ERT, followed by acquisition, maintenance and operating costs. The study also finds that increasing redundant costs per hour have a negative effect on ERT, while decreases in other costs have a positive effect. Regression analysis shows a linear relationship between the cost factors and ERT. Practical implications – The proposed approach can be used by the decision maker in determining the ERT of production machines which used in mining industry. Originality/value – The research proposed in this paper provides and develops an optimisation model for ERT of mining machines. This research also identifies and explains the factors that have the largest impact on the production machine’s ERT. This model for estimating the ERT has never been studied on mining drilling rigs.

scholarly journals Optimising truck arrival management and number of service gates at container terminals

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chu Cong Minh ◽  
Nguyen Van Noi
Keyword(s):  
Time Slot ◽  
The United States ◽  
Container Terminals ◽  
Queuing Model ◽  
Content Type ◽  
Total Cost ◽  
Container Ports ◽  
Appointment System ◽  
Optimisation Model ◽  
Truck Appointment System

PurposeTruck appointment systems have been applied in critical container ports in the United States due to their potential to improve handling operations. This paper aims to develop a truck appointment system to optimise the total cost experiencing at the entrance of container terminals by managing truck arrivals and the number of service gates satisfying a given level of service.Design/methodology/approachThe approximation of Mt/G/nt queuing model is applied and integrated into a cost optimisation model to identify (1) the number of arrival trucks allowed at each time slot and (2) the number of service gates operating at each time slot that ensure the average waiting time is less than a designated time threshold. The optimisation model is solved by the Genetic Algorithm and tested with a case study. Its effectiveness is identified by comparing the model's outcomes with observed data and other recent studies.FindingsThe results indicate that the developed truck appointment system can provide more than threefold and twofold reductions of the total cost experiencing at the terminal entrance compared to the actual data and results from previous research, respectively.Originality/valueThe proposed approach provides applicably coordinated truck plans and operating service gates efficiently to decrease congestion, emission and expenses.

A novel optimisation model in the collaborative supply chain with production time capacity consideration

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Muhammad Ridwan Andi Purnomo ◽  
Adhe Rizky Anugerah ◽  
Salvia Fatma Aulia ◽  
Abdullah ‘Azzam
Keyword(s):  
Supply Chain ◽  
Low Cost ◽  
Transportation Cost ◽  
Production Costs ◽  
Furniture Industry ◽  
Production Time ◽  
Content Type ◽  
Total Cost ◽  
Penalty Cost ◽  
Optimisation Model

Purpose This study aims to propose an optimal procurement model of the collaborative supply chain in the furniture industry. The final output is the total cost minimisation to produce a furniture product that covers material cost, processing cost, transportation cost and holding cost. Therefore, if companies can give the best value to customers at a low cost, then competitive advantages can be achieved. Design/methodology/approach A genetic algorithm (GA) as a metaheuristic approach was used to solve problems in this research. The optimisation was initiated by developing a mathematical model to formulate the objective function. Findings Based on the case study, the proposed GA model was able to reduce the total cost of production. The cost was reduced by 73.09% compared to the existing system. Besides, the production time of the proposed model is within the capacity of both companies; hence, no penalty cost is imposed. Practical implications The proposed GA model has been implemented and tested to minimise production costs in the Indonesian furniture industry. Originality/value To the best of author knowledge, there is no research has proposed an optimisation model that incorporates production cost, transportation cost and production time capacity together in the collaborative supply chain. This research is the first to collaborate these factors using GA in the furniture industry.

Association between outpatient orthopedic surgery costs and healthcare facility characteristics

2018 ◽  
Vol 31 (3) ◽  
pp. 265-272 ◽  
Author(s):  
Yuichi Watanabe ◽  
Yoshinori Nakata
Keyword(s):  
Regression Analysis ◽  
Orthopedic Surgery ◽  
Multivariate Regression ◽  
Healthcare Facility ◽  
Ordinary Least Squares ◽  
Patient Specific ◽  
Content Type ◽  
Healthcare Facilities ◽  
Total Cost ◽  
Surgical Costs

Purpose The purpose of this paper is to examine the association between outpatient orthopedic surgery costs and Japan’s healthcare facilities using a large-scale Japanese medical claims database. Design/methodology/approach The authors obtained reimbursement claims data for 8,588 patients who underwent orthopedic surgery between April 1 and September 30, 2014 at 3,347 Japanese healthcare facilities. Regression analysis, using ordinary least squares, examined the association between outpatient orthopedic surgery costs and healthcare facility characteristics. By using surgical fees as proxy for the surgical costs, the authors defined three dependent variables: surgical cost for each outpatient orthopedic surgery; pre- and post-operative cost one month before and after a surgical operation; and total cost for each patient. The authors also defined five independent variables, which capture healthcare facility characteristics and patient-specific factors: bed count; whether healthcare facilities are reimbursed in a diagnosis procedure combination system; patient’s age; sex; and anatomical surgical sites. Findings The authors analyzed 6,456 outpatient orthopedic surgical cases performed at 3,085 healthcare facilities. There were significant differences in the surgical costs for outpatient orthopedic surgery among different healthcare facilities by total beds (p=0.000). Multivariate regression analysis shows that surgical costs for outpatient orthopedic surgery are positively and significantly associated with healthcare facilities classified by total beds after adjusting for patient-specific characteristics (p<0.05). Originality/value This is the first research to examine the association between costs for outpatient orthopedic surgery and healthcare facility characteristics in Japan. This study via the multivariate regression method showed that outpatient orthopedic surgery is likely to cost higher as healthcare facility size increased. The average incremental costs for each outpatient orthopedic surgery per 100 beds were calculated at $48.5 for surgery, $40.7 for pre- and post-operative care, and $89.2 total cost.

The workplace as a factor of job satisfaction and productivity

2015 ◽  
Vol 13 (4) ◽  
pp. 332-349 ◽  
Author(s):  
Konstantinos Fassoulis ◽  
Nikolaos Alexopoulos
Keyword(s):  
Job Satisfaction ◽  
Regression Analysis ◽  
Descriptive Analysis ◽  
Public Institution ◽  
Employee Productivity ◽  
Administrative Staff ◽  
Office Work ◽  
Content Type ◽  
Negative Effect ◽  
The Impact

Purpose – The purpose of this study is to examine degree of job satisfaction of the University of Athen’s (UOA) administrative staff, specifically regarding the workplace and its impact on their productivity. Design/methodology/approach – Questionnaires were distributed to 160 administrative personnel of the UOA. The study entails descriptive analysis, independent samples t-tests, ANOVA, Pearson correlations (two-tailed) and regression analysis of the data collected. Findings – The results indicate that the UOA’s administrative staff is dissatisfied with most aspects of their workplace, which is characterized by an inability to encourage and support new forms of office work. This scenario was also found to have a negative effect on productivity. In addition, regression analysis showed that satisfaction with the workplace is a significant predictor of employee productivity. Research limitations/implications – A limitation of this study is that the sample was not from the UOA administrative staff that works in more recently constructed office buildings away from the Athens city center. Further investigation would also be needed to identify possible differences in satisfaction with the workspace and its impact on productivity, based on demographic characteristics, such as the level of education and years of employment. Practical implications – The research results may be useful to public institution administrations like that of the UOA, as it highlights changes in the workplace which can have significant impact on employee job satisfaction and productivity, and consequently, the efficiency and effectiveness of the services provided. Originality/value – This study examines aspects of the workspace of a public organization regarding their individual attributes. Given that the existing Greek literature in this field does not contain a discussion on the impact of the workplace on job satisfaction and productivity as far as the public sector is concerned, this paper may contribute to a smoother and more efficient provision of services from its organizations/institutions.

scholarly journals Life cycle cost analysis of the ventilation system in Stockholm’s road tunnels

2018 ◽  
Vol 24 (3) ◽  
pp. 358-375 ◽  
Author(s):  
Hussan Saed Al-Chalabi
Keyword(s):  
Life Cycle Cost ◽  
Decision Model ◽  
Ventilation System ◽  
Operating Cost ◽  
Life Cycle Cost Analysis ◽  
Content Type ◽  
Proposed Model ◽  
Road Tunnels ◽  
Optimisation Model ◽  
Replacement Time

Purpose The purpose of this paper is to develop a practical economic replacement decision model to identify the economic lifetime of the ventilation system used by Trafikverket in its Stockholm tunnels. Design/methodology/approach The proposed data-driven optimisation model considers operating and maintenance costs, purchase price and system resale value for a ventilation system consisting of 121 fans. The study identified data quality problems in Trafikverket’s MAXIMO database. Findings It is found that the absolute economic replacement time (ERT) of the ventilation system is 108 months but for a range of 100–120 months, the total cost remains almost constant. Sensitivity and regression analysis showed that the operating cost has the largest impact on the ERT. Originality/value The results are promising; the company has the possibility of significantly reducing the LCC of the ventilation system by optimising its lifetime. In addition, the proposed model can be used for other systems with repairable components, making it applicable, useful and implementable within Trafikverket more generally.

PENGARUH GAYA KEPEMIMPINAN, MOTIVASI KERJA DAN KOMPETENSI TERHADAP KINERJA PEGAWAI PADA DINAS PEMBERDAYAAN MASYARAKAT DAN DESA PROVINSI SUMATERA BARAT

2020 ◽  
Author(s):  
Mafral
Keyword(s):  
Regression Analysis ◽  
Leadership Style ◽  
Work Motivation ◽  
Employee Performance ◽  
High Reliability ◽  
Test Results ◽  
Eligibility Criteria ◽  
Validity Test ◽  
Negative Effect ◽  
Independent Variable

The independent independent variables in this study as many as 89 respondents are determined by using saturated samples. To know the influence of independent variable to dependent variable partially, used t test. While to know the effect of independent variable to dependent variable simultaneously, used F test. The assumption used in the validity test is if R-count&gt; R-table item is declared valid. The R-arithmetic shown in the table above, from each item indicates that R-arithmetic&gt; R- table so the item is declared valid. Based on the validity test of the instrument of Leadership Style, Work Motivation, and Competence on Employee Performance, all items are declared valid and reliability test results indicate that the instrument has high reliability. This means that the eligibility criteria of the Instrument of Leadership Style, Work Motivation, Competency and Employee Performance have met the criteria of good instrument requirements, that is valid and reliable. The result of regression analysis of Leadership Style obtained by tcount = 20,91 while ttable value = 1,988 tcount&gt; ttable proved variable of Leadership Style influence to Employee Performance. Work Motivation regression analysis obtained tcount = 17.62 while the value ttable = 1.988 tcount&gt; ttabel proven Motivational Work variables influence on Employee Performance. Regression analysis Competence obtained value tcount = - 06.85 while ttable =1.988 so thitung&gt; ttable and proven variable Competence have a negative effect on Employee Performance.

The path of support-to-sales: mediating role of seller collaborative information exchange in social commerce

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Li Chen ◽  
Fengxia Zhu ◽  
Murali Mantrala
Keyword(s):  
Information Exchange ◽  
Instrumental Support ◽  
Trade Volume ◽  
Social Commerce ◽  
Content Type ◽  
Mediating Role ◽  
The Social ◽  
Source Data ◽  
Negative Effect

Purpose This paper aims to systematically investigate the direct and indirect effects of four types of support – peer instrumental support, peer emotional support, platform business support and platform communication support – on seller trade volume in social commerce. It also aims to uncover the path of support-to-sales of the seller from a platform perspective and provides a more complete picture of the social commerce phenomenon. Design/methodology/approach This paper uses multi-source data including primary survey data and secondary data on trade volume to test the hypotheses. PROCESS mediation model is used to analyze the multi-source data set. Findings This study finds that the positive effects of peer instrumental support, platform business support and platform communication support on seller trade volume are fully mediated by seller collaborative information exchange. Also, peer emotional support has a significant negative effect on seller trade volume and collaborative information exchange can serve as a buffer to mitigate the negative effect. Research limitations/implications The authors provide new insights into what types of support are or are not conducive to improving transaction volume of individual sellers and highlight the mediating role of seller information exchange in this value generation process in social commerce. These findings advance current knowledge of how seller interactions increase value in social commerce. The chosen research setting may limit the generalizability of the findings of this study. Practical implications This paper offers valuable implications for social commerce platforms on how to better serve their sellers to achieve high growth. Specifically, the findings suggest that platforms should encourage instrumental support and information exchange among peer sellers. In addition, platforms should expand seller support from a single-focus on sellers’ business to a dual-focus on both sellers’ business and socialization in social commerce. Originality/value This paper fulfills an identified need to study how sellers can better derive value from the social interactions and how social commerce platforms can effectively influence transactions, support sales and serve as a selling platform.

Effect of education on migration decisions in Ghana: a rural-urban perspective

2016 ◽  
Vol 43 (2) ◽  
pp. 336-356 ◽  
Author(s):  
Franklin Amuakwa-Mensah ◽  
Louis Boakye-Yiadom ◽  
William Baah-Boateng
Keyword(s):  
Educational Attainment ◽  
Rural Areas ◽  
Migration Decision ◽  
Skilled Workers ◽  
Mixed Effect ◽  
Content Type ◽  
Rural And Urban ◽  
Migration Decisions ◽  
Negative Effect ◽  
The Impact

Purpose – The purpose of this paper is to investigate the effect of education on migration decisions focusing on rural and urban in-migrants by comparing the 2005/2006 and 2012/2013 rounds of the Ghana Living Standards Survey (GLSS5 and GLSS6). After correcting for selectivity bias, the authors observed that anticipated welfare gain and socio-economic variables such as sector of employment, sex, experience, age, educational level and marital status significantly affect an individual’s migration decision. Design/methodology/approach – The authors made use of Sjaastad’s (1962) human capital framework as a basis for examining the impact of education on migration. The migration decision equation was based on the Heckman two stage procedure. Findings – While educational attainment is observed to have a positive effect on migration decision in the period 2005/2006, the authors find a negative effect of educational attainment on migration decision in the period 2012/2013. The effect of educational attainment on migration decision in 2005/2006 for urban in-migrant is higher than the effect for rural in-migrant, with its significance varying for the different stages of educational attainment. In absolute terms, whereas the effect of secondary educational attainment on migration decisions for urban in-migrant is higher than that of rural in-migrant, the reverse holds for higher educational attainment during the period 2012/2013. Social implications – Based on the mixed effect of education on migration decision as evident from the study, policies to enhance the educational system in Ghana should be complemented with job creations in the entire country. Moreover, special attention should be given to the rural sector in such a way that the jobs to be created in the sector do not require skilled workers. With quality education and job creation, the welfare of individuals living in urban and rural areas will be enhanced. Originality/value – In spite of the importance of education in migration decisions, there is scanty literature on the rural-urban dimension. To the best of the author’s knowledge there is no literature in the Ghanaian context which examines the rural and urban perspective of the impact of education on migration with a much recent data. Further, the author consider how the determinants of migration decision have changed over time focusing on rural and urban perspectives.

Prediction of Surface Roughness in Magneto Rheological Abrasive Flow Finishing Process by Artificial Neural Networks and Regression Analysis

2015 ◽  
Vol 766-767 ◽  
pp. 1076-1084
Author(s):  
S. Kathiresan ◽  
K. Hariharan ◽  
B. Mohan
Keyword(s):  
Neural Network ◽  
Surface Roughness ◽  
Regression Analysis ◽  
Back Propagation ◽  
Hydraulic Pressure ◽  
Artificial Neural ◽  
Artificial Neural Network Ann ◽  
Magneto Rheological ◽  
Hidden Neurons ◽  
Abrasive Flow Finishing

In this study, to predict the surface roughness of stainless steel-304 in Magneto rheological Abrasive flow finishing (MRAFF) process, an artificial neural network (ANN) and regression models have been developed. In this models, the parameters such as hydraulic pressure, current to the electromagnet and number of cycles were taken as variables of the model.Taguchi’s technique has been used for designing the experiments in order to observe the different values of surface roughness . A neural network with feed forward with the help of back propagation was made up of 27 input neurons, 7 hidden neurons and one output neuron. The 6 sets of experiments were randomly selected from orthogonal array for training and residuals were used to analyze the performance. To check the validity of regression model and to determine the significant parameter affecting the surface roughness, Analysis of variance (ANOVA) andF-test were made. The numerical analysis depict that the current to the electromagnet was an paramount parameter on surface roughness.Key words: MRAFF, ANN, Regression analysis

Gender diversity and innovation in mining – a corpus-based discourse analysis

2017 ◽  
Vol 9 (4) ◽  
pp. 359-376 ◽  
Author(s):  
Ylva Fältholm ◽  
Cathrine Norberg
Keyword(s):  
Discourse Analysis ◽  
Gender Diversity ◽  
Mining Industry ◽  
Diversity Management ◽  
Business Case ◽  
Female Representation ◽  
Policy Makers ◽  
Content Type ◽  
Gender Patterns ◽  
Practical Implications

Purpose The purpose of this study is to gain increased knowledge about gender diversity and innovation in mining by analyzing how women are discursively represented in relation to these two concepts, and in doing so establish how diversity management is received and communicated in the industry. Design/methodology/approach The study is based on analysis of texts including references to gender diversity and innovation in mining found on the web. The tool used to retrieve the data has been WebCorpLive, a tool designed for linguistic analysis of web material. Findings Although increased female representation is communicated as a key component in the diversity management discourse, based on the idea that diversity increases innovation and creativity, closer analysis of texts on diversity and innovation in mining shows that what women are expected to contribute with has little explicit connection with innovation. Research limitations/implications The study contributes with increased knowledge about diversity management by providing an example of how it is received in a traditionally male-dominated industry. Practical implications The findings indicate that for diversity management to have a real effect in mining, it needs to be based on gender equality and social justice motives, rather than on a business case rationale – the principal motive today. To enable this change, stereotypical gender patterns, as shown in this study, need to be made visible and problematized among policy makers, practitioners and actors on all levels of the industry. Originality value The study contributes with new knowledge about gender in the mining industry previously not attended to by using a method which so far has been sparsely used in discourse analysis, although pointed out as promising.

Sign in / Sign up

Export Citation Format

Share Document