The impact of preventive maintenance practices on manufacturing performance: A proposed model for SMEs in Malaysia

Purpose The purpose of this paper is to present a decision model for second-hand products to determine the optimal upgrade level, warranty period and preventive maintenance (PM) effort level which maximize the total expected profit generated by the dealer considering any given past age of the product and the effect of the sales volume. Design/methodology/approach A mathematical model is developed to derive the optimal triplet: upgrade level, warranty period and PM effort level, which maximize the total expected profit generated by the dealer for any second-hand product with a given past age. Numerical experimentations have been conducted to investigate the effectiveness of the proposed model and to explore the interactions among the model variables. Findings Numerical experimentations including a sensitivity analysis have been conducted on the model key parameters. The obtained results show that performing PM actions during the warranty period helps the dealers to provide extended warranty for older second-hand products without spending a significant effort on upgrade actions and therefore increase the volume of sales. Also, the interaction between the PM level and the profit margin threshold is demonstrated. Finally, the effect of the sales volume function parameters (the price and warranty elasticity parameters) on the optimal solution is characterized. Research limitations/implications Given the complexity of the profit function to be maximized involving a considerable number of decision variables with different nature, the authors limited the study to the case where the past age of the second-hand product is known. Practical implications The proposed model aims to provide second-hand product dealers with a modeling framework that enables them to have a realistic estimation of the generated profit by integrating the marketing and engineering key parameters of the second-hand product. Originality/value Most of the existing literature dealing with the reliability improvement of second-hand products does not take into account the fact that a realistic estimation of the total profit generated by the dealer requires the consideration of the sales volume. The latter is closely related to the marketing parameters characterized by the warranty period length and the second-hand product selling price. The proposed model introduces the effect of the total sales volume on the total expected profit. The authors also introduce the concept of discrete upgrade levels for a better control of the restoration degree. The authors study the impact of warranty and price elasticity parameters on the optimal solution and the resultant interaction with the customer purchase decision and consequently the sales volume.

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Analytical evaluation of TPM performance based on an economic criterion

Journal of Quality in Maintenance Engineering ◽

10.1108/jqme-08-2019-0085 ◽

2020 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Kenza Chaabane ◽

Jérémie Schutz ◽

Sofiene Dellagi ◽

Wajdi Trabelsi

Keyword(s):

Preventive Maintenance ◽

Sensitivity Study ◽

Analytical Models ◽

Total Productive Maintenance ◽

Economic Criterion ◽

Content Type ◽

Decision Variables ◽

Manufacturing Performance ◽

The Impact ◽

A Company

PurposeTotal productive maintenance (TPM) has been widely recognized as a strategic weapon for improving manufacturing performance. Evaluate efficiency of TPM implementation is considered as a key element in order to motivate staff and to give decision-makers more confidence.Design/methodology/approachThis study consists in developing a new method of evaluating TPM implementation, relying on analytical models and considering two preventive maintenance strategies: periodic and age-dependent.FindingsThe preventive maintenance period and TPM period defined as decision variables are obtained simultaneously by maximizing the expected profit under TPM implementation. A numerical example is presented and a sensitivity study is developed to validate the proposed models.Originality/valueThe aim of this research is to quantify, through analytic development, the impact of TPM implementation in a company by calculating and comparing the profit made with and without TPM.

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The impact of sustainable manufacturing practices on sustainability performance

International Journal of Operations & Production Management ◽

10.1108/ijopm-04-2015-0223 ◽

2017 ◽

Vol 37 (2) ◽

pp. 182-204 ◽

Cited By ~ 88

Author(s):

Salwa Hanim Abdul-Rashid ◽

Novita Sakundarini ◽

Raja Ariffin Raja Ghazilla ◽

Ramayah Thurasamy

Keyword(s):

Sustainable Manufacturing ◽

Manufacturing Industries ◽

Manufacturing Companies ◽

Content Type ◽

Sustainability Performance ◽

Proposed Model ◽

Manufacturing Performance ◽

Relationship Of ◽

Sustainability Assessments ◽

The Impact

Purpose Sustainable manufacturing practices are one of the significant environmental initiatives taken by manufacturing industries to preserve the environment and improve the quality of human life while performing manufacturing activities. The emergence of the value creation concept, economic value no longer counts as a single factor for measuring manufacturing performance. Within the sustainability context, the impact of manufacturing activities on the environmental and social aspects should be taken into account as the basis for assessing manufacturing performance, which is called sustainability performance. The purpose of this paper is to examine the relationship of sustainable manufacturing practices with sustainability performance, which considers the environmental, economic and social aspects. Design/methodology/approach A questionnaire survey is carried out among 443 ISO 14001 certified manufacturing companies in Malaysia. Structural equation modelling is used to evaluate the relationship of sustainable manufacturing practices with sustainability performance. Findings The findings of this study indicate that manufacturing process is the manufacturing stage that gives the most impact on the improvement of sustainability performance. Hence, it is concluded that manufacturing companies in Malaysia are highly focussed on the production bound when implementing sustainable manufacturing practices. Research limitations/implications Although this study indicates a good estimation of the proposed model, additional variables might be added to improve the prediction strength of the proposed model such as considering type of industries, economic scale or ownership. Adding the comparison of sustainable manufacturing practices between different countries also a valuable research to investigated. Practical implications The framework proposed here can also assist manufacturing industries to conduct sustainability assessments by providing elements of sustainability performance and can serve as a guideline to select appropriate sustainable manufacturing practices and to what level the practices need to be improved to leverage companies’ sustainability performance. Originality/value The framework proposed here can also assist manufacturing industries to conduct sustainability assessments by providing elements of sustainability performance and can serve as a guideline to select appropriate sustainable manufacturing practices and to what level the practices need to be improved to leverage companies’ sustainability performance.

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Test of Mediation and Moderation between Employee Empathy and Customers’ Advocacy

10.34091/ajss.13.1.09 ◽

2020 ◽

Author(s):

Sajjad Ahmad Afridi ◽

Asad Shahjehan ◽

Maqsood Haider ◽

Dr Uzma Munawar

Keyword(s):

Factor Analysis ◽

Customer Loyalty ◽

Service Sector ◽

Mediating Effect ◽

First Line ◽

Private Hospitals ◽

Proposed Model ◽

Confirmatory Factor ◽

The Impact ◽

Significant Moderator

This study examined the impact of employee empathy on customers’ advocacy directly and indirectly through customers’ loyalty. Moreover, the interacting effect of customers’ trust was verified between the association of customers’ loyalty and advocacy. The attributes of the proposed model were examined in the context of first line employee and patients’ interactions. A total of 220 responses were collected for analysis from the private hospitals of Peshawar. The model fitness was confirmed through confirmatory factor analysis and hypotheses were examined. Findings confirmed the positive and significant impact of employee empathy on customers’ advocacy. Further, the mediating effect was examined and found that loyalty partially mediates employee empathy and customers’ advocacy. Additionally, trust was found a significant moderator between the association of customer loyalty and advocacy. Furthermore, findings revealed that trust based loyalty significantly and positively mediates employee empathy and customers’ advocacy. Findings of the present study provide understanding for the service sector, particularly in healthcare, to enhance customers’ loyalty, advocacy, and trust through service employee’s empathic aptitude. Keywords: Employee empathy, Service Eco-system, Customers’ Loyalty, Customers’ Advocacy, Trust-Based Loyalty, Healthcare, S-D Logic

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The impact of duration observations on precision of results GNSS measurements

Geodesy and Cartography ◽

10.22389/0016-7126-2017-921-3-7-13 ◽

2017 ◽

Vol 921 (3) ◽

pp. 7-13 ◽

Cited By ~ 1

Author(s):

S.V. Grishko

Keyword(s):

Measurement Accuracy ◽

Functional Dependence ◽

Observation Time ◽

Satellite Networks ◽

Satellite Measurements ◽

Proposed Model ◽

Actual Error ◽

Gnss Measurements ◽

The Impact ◽

Qualitative Characteristics

This paper shows that the accuracy of relative satellite measurements depend not only on the length of the baseline, as it is regulated by the rating formula of accuracy of GNSS equipment, but also on the duration of observations. As a result of the strict adjustment much redundant satellite networks with different duration of observations obtained covariance matrix of baselines, the most realistic reflecting the actual error of satellite observations. Research of forms of communication of these errors from length of the baseline and duration of its measurement is executed. A significant influence of solar activity on accuracy of satellite measurements, in general, leads to unequal similar series of measurements made at different periods, for example, in the production of monitoring activities. The model of approximation of the functional dependence of accuracy of the baseline from its length and duration of observations having good qualitative characteristics is offered. Based on the proposed model, we analyzed the dynamics of changes in measurement accuracy with an increase in observation time.

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The impact of quarantine on Covid-19 infections

Epidemiologic Methods ◽

10.1515/em-2020-0038 ◽

2021 ◽

Vol 10 (s1) ◽

Author(s):

Pablo Marshall

Keyword(s):

Health System ◽

Infection Rate ◽

District Level ◽

Infection Model ◽

Social Distancing ◽

Proposed Model ◽

Lower Infection ◽

The Impact ◽

Lower Infection Rate ◽

Over Time

Abstract Objectives: Coronavirushas had profound effects on people’s lives and the economy of many countries, generating controversy between the need to establish quarantines and other social distancing measures to protect people’s health and the need to reactivate the economy. This study proposes and applies a modification of the SIR infection model to describe the evolution of coronavirus infections and to measure the effect of quarantine on the number of people infected. Methods: Two hypotheses, not necessarily mutually exclusive, are proposed for the impact of quarantines. According to the first hypothesis, quarantine reduces the infection rate, delaying new infections over time without modifying the total number of people infected at the end of the wave. The second hypothesis establishes that quarantine reduces the population infected in the wave. The two hypotheses are tested with data for a sample of 10 districts in Santiago, Chile. Results: The results of applying the methodology show that the proposed model describes well the evolution of infections at the district level. The data shows evidence in favor of the first hypothesis, quarantine reduces the infection rate; and not in favor of the second hypothesis, that quarantine reduces the population infected. Districts of higher socio-economic levels have a lower infection rate, and quarantine is more effective. Conclusions: Quarantine, in most districts, does not reduce the total number of people infected in the wave; it only reduces the rate at which they are infected. The reduction in the infection rate avoids peaks that may collapse the health system.

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An adaptive social distancing SIR model for COVID-19 disease spreading and forecasting

Epidemiologic Methods ◽

10.1515/em-2020-0044 ◽

2021 ◽

Vol 10 (s1) ◽

Author(s):

Said Gounane ◽

Yassir Barkouch ◽

Abdelghafour Atlas ◽

Mostafa Bendahmane ◽

Fahd Karami ◽

...

Keyword(s):

Mathematical Theory ◽

Real Data ◽

Sir Model ◽

Epidemic Threshold ◽

Social Distancing ◽

Sir Epidemic ◽

Proposed Model ◽

Disease Spreading ◽

The Government ◽

The Impact

Abstract Recently, various mathematical models have been proposed to model COVID-19 outbreak. These models are an effective tool to study the mechanisms of coronavirus spreading and to predict the future course of COVID-19 disease. They are also used to evaluate strategies to control this pandemic. Generally, SIR compartmental models are appropriate for understanding and predicting the dynamics of infectious diseases like COVID-19. The classical SIR model is initially introduced by Kermack and McKendrick (cf. (Anderson, R. M. 1991. “Discussion: the Kermack–McKendrick Epidemic Threshold Theorem.” Bulletin of Mathematical Biology 53 (1): 3–32; Kermack, W. O., and A. G. McKendrick. 1927. “A Contribution to the Mathematical Theory of Epidemics.” Proceedings of the Royal Society 115 (772): 700–21)) to describe the evolution of the susceptible, infected and recovered compartment. Focused on the impact of public policies designed to contain this pandemic, we develop a new nonlinear SIR epidemic problem modeling the spreading of coronavirus under the effect of a social distancing induced by the government measures to stop coronavirus spreading. To find the parameters adopted for each country (for e.g. Germany, Spain, Italy, France, Algeria and Morocco) we fit the proposed model with respect to the actual real data. We also evaluate the government measures in each country with respect to the evolution of the pandemic. Our numerical simulations can be used to provide an effective tool for predicting the spread of the disease.

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A modified SEIR model to predict the behavior of the early stage in coronavirus and coronavirus-like outbreaks

Scientific Reports ◽

10.1038/s41598-021-95785-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Wilfredo Angulo ◽

José M. Ramírez ◽

Dany De Cecchis ◽

Juan Primera ◽

Henry Pacheco ◽

...

Keyword(s):

Molecular Structure ◽

Risk Perceptions ◽

Transmission Rate ◽

Early Stage ◽

Individual Risk ◽

Seir Model ◽

Proposed Model ◽

Probable Site ◽

Adjusted Model ◽

The Impact

AbstractCOVID-19 is a highly infectious disease that emerged in China at the end of 2019. The COVID-19 pandemic is the first known pandemic caused by a coronavirus, namely, the new and emerging SARS-CoV-2 coronavirus. In the present work, we present simulations of the initial outbreak of this new coronavirus using a modified transmission rate SEIR model that takes into account the impact of government actions and the perception of risk by individuals in reaction to the proportion of fatal cases. The parameters related to these effects were fitted to the number of infected cases in the 33 provinces of China. The data for Hubei Province, the probable site of origin of the current pandemic, were considered as a particular case for the simulation and showed that the theoretical model reproduces the behavior of the data, thus indicating the importance of combining government actions and individual risk perceptions when the proportion of fatal cases is greater than $$4\%$$ 4 % . The results show that the adjusted model reproduces the behavior of the data quite well for some provinces, suggesting that the spread of the disease differs when different actions are evaluated. The proposed model could help to predict outbreaks of viruses with a biological and molecular structure similar to that of SARS-CoV-2.

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Optimizing a Reverse Supply Chain Network for Electronic Waste under Risk and Uncertain Factors

Applied Sciences ◽

10.3390/app11041946 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1946

Author(s):

Linh Thi Truc Doan ◽

Yousef Amer ◽

Sang-Heon Lee ◽

Phan Nguyen Ky Phuc ◽

Tham Thi Tran

Keyword(s):

Supply Chain ◽

Electronic Waste ◽

Decision Makers ◽

Reverse Supply Chain ◽

Satisfactory Solution ◽

Level Of Satisfaction ◽

Proposed Model ◽

Objective Value ◽

The Right ◽

The Impact

Minimizing the impact of electronic waste (e-waste) on the environment through designing an effective reverse supply chain (RSC) is attracting the attention of both industry and academia. To obtain this goal, this study strives to develop an e-waste RSC model where the input parameters are fuzzy and risk factors are considered. The problem is then solved through crisp transformation and decision-makers are given the right to choose solutions based on their satisfaction. The result shows that the proposed model provides a practical and satisfactory solution to compromise between the level of satisfaction of constraints and the objective value. This solution includes strategic and operational decisions such as the optimal locations of facilities (i.e., disassembly, repairing, recycling facilities) and the flow quantities in the RSC.

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A Two-Population Mortality Model to Assess Longevity Basis Risk

Risks ◽

10.3390/risks9020044 ◽

2021 ◽

Vol 9 (2) ◽

pp. 44

Author(s):

Selin Özen ◽

Şule Şahin

Keyword(s):

Risk Reduction ◽

Significant Risk ◽

Reference Population ◽

Mortality Data ◽

Basis Risk ◽

Mortality Model ◽

Proposed Model ◽

Population Mortality ◽

Mortality Jumps ◽

The Impact

Index-based hedging solutions are used to transfer the longevity risk to the capital markets. However, mismatches between the liability of the hedger and the hedging instrument cause longevity basis risk. Therefore, an appropriate two-population model to measure and assess longevity basis risk is required. In this paper, we aim to construct a two-population mortality model to provide an effective hedge against the basis risk. The reference population is modelled by using the Lee–Carter model with the renewal process and exponential jumps, and the dynamics of the book population are specified. The analysis based on the U.K. mortality data indicate that the proposed model for the reference population and the common age effect model for the book population provide a better fit compared to the other models considered in the paper. Different two-population models are used to investigate the impact of sampling risk on the index-based hedge, as well as to analyse the risk reduction regarding hedge effectiveness. The results show that the proposed model provides a significant risk reduction when mortality jumps and sampling risk are taken into account.

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