Integrated maintenance scheduling inventory policy adjustment considering back order disruptions using joint optimization approach

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Samane Babaeimorad ◽  
Parviz Fattahi ◽  
Hamed Fazlollahtabar
Keyword(s):  
Numerical Algorithm ◽  
Production System ◽  
Order Type ◽  
Joint Optimization ◽  
Optimization Approach ◽  
Maximum Throughput ◽  
Content Type ◽  
Holding Cost ◽  
The Cost ◽  
Back Order

PurposeThe purpose of this paper is to present an integrated strategy for inventory control and preventive maintenance planning for a single-machine production system with increasing failure rates.Design/methodology/approachThere are three scenarios for solving presented model. The strategy is such that the production component is placed under maintenance as soon as it reaches the m level or in the event of a malfunction earlier than m. Maintenance completion time is not predictable. As a result of periodic maintenance, a buffer stock h is held and the production component starts to produce from period A with the maximum throughput to satisfy demand and handle the shortage. A numerical algorithm to find the optimal policy is developed. The algorithm is implemented using MATLAB software.FindingsThe authors discovered that joint optimization mainly reduces production system costs. Cs is holding cost of a product unit during a unit of time. The authors consider two values for Cs, consist of, Cs = 1 and Cs = 2. By comparing the two cases, it is concluded that by reducing the cost from Cs = 2 to Cs = 1, the optimal scenario does not differ. The amount of decision variables decreases.Originality/valueThis paper is the provision of a model in which the shortage of back order type is considered, which greatly increases the complexity of the problem compared to similar issues. The methods for solving such problems are provided by the numerical algorithm, and the use of buffers as a way to compensate for the shortage in the event of a complete shutdown of the production line which is a very effective and efficient way to deal with customer loss.

Robust optimization approach to production system with failure in rework and breakdown under uncertainty: evolutionary methods

2015 ◽  
Vol 35 (1) ◽  
pp. 81-93 ◽  
Author(s):  
Masoud Rabbani ◽  
Neda Manavizadeh ◽  
Niloofar Sadat Hosseini Aghozi
Keyword(s):  
Mathematical Model ◽  
Robust Optimization ◽  
Production Planning ◽  
Production System ◽  
Demand Uncertainty ◽  
Optimization Techniques ◽  
Planning Problem ◽  
Optimization Approach ◽  
Content Type ◽  
Evolutionary Methods

Purpose – This paper aims to consider a multi-site production planning problem with failure in rework and breakdown subject to demand uncertainty. Design/methodology/approach – In this new mathematical model, at first, a feasible range for production time is found, and then the model is rewritten considering the demand uncertainty and robust optimization techniques. Here, three evolutionary methods are presented: robust particle swarm optimization, robust genetic algorithm (RGA) and robust simulated annealing with the ability of handling uncertainties. Firstly, the proposed mathematical model is validated by solving a problem in the LINGO environment. Afterwards, to compare and find the efficiency of the proposed evolutionary methods, some large-size test problems are solved. Findings – The results show that the proposed models can prepare a promising approach to fulfill an efficient production planning in multi-site production planning. Results obtained by comparing the three proposed algorithms demonstrate that the presented RGA has better and more efficient solutions. Originality/value – Considering the robust optimization approach to production system with failure in rework and breakdown under uncertainty.

A unique mathematical optimization approach for examination of failure effects on electric power transmission grids by combined environmental and economic indicators

2017 ◽  
Vol 14 (3) ◽  
pp. 237-248
Author(s):  
Ali Azadeh ◽  
Maryam Sattarian ◽  
Azadeh Arjmand
Keyword(s):  
Power System ◽  
Electric Power ◽  
Power Flow ◽  
Power Transmission ◽  
Environmental Issues ◽  
Influential Factors ◽  
Optimization Approach ◽  
Content Type ◽  
Total Cost ◽  
The Cost

Purpose To achieve the optimum performance of electric transmission power system performance, the possibility of generators’ failure and the consequences are amongst the most important and real assumptions which should be taken into consideration. This paper aims to recognize the most influential factors on generators’ failures that can have a deep effect on the total cost and environmental issues. The integrated proposed approach is useful for investigating the generators’ failure effects on the performance of electric power transmission grids from the economic and environmental perspectives. In other words, the cost and pollution minimization policies are considered to decrease the unfavorable generators’ failure effects on electric power flow. Design/methodology/approach The data used in this study are gathered from a real case in USA in first step, the influential generator points that their failure has a significant effect on the objective function, have been recognized. Then, different failure scenarios are defined, and the optimum values in each of these scenarios through the GAMS modeling software are found. Consequently, by using a two-level factorial design approach, the critical generators across the power grid are determined. Findings The results show that by using such information, it is possible to detect the significant nodes in the power system grid and have a better maintenance plan. In addition, by means of this analysis and changing the capacity of main generators, it is possible to significantly reduce the operation costs. By comparing the indexes in case of the generator’s location, it seems that some of them are critical because of their capacity and position in the network (as their failure causes infeasibility in the model). Also, some of these deficiencies caused considerable index changes and critical consequences. Practical implications The integrated proposed approach is useful for investigating the generators’ failure effects on the performance of electric power transmission grids from the economic and environmental perspectives. In other words, the cost and pollution minimization policies are considered to decrease the unfavorable generators’ failure effects on electric power flow. Social implications This paper endeavors to recognize the most influential factors on generators’ failures that can have a deep effect on the total cost and environmental issues. Originality/value The integrated proposed approach is useful for investigating the generators’ failure effects on the performance of electric power transmission grids from the economic and environmental perspectives. In other words, the cost and pollution minimization policies are considered to decrease the unfavorable generators’ failure effects on electric power flow.

An inventory model for fish marketing under uncertain lockdown situation and normal backordering situation

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kuppulakshmi V ◽  
Sugapriya C ◽  
Nagarajan Deivanayagam Pillai
Keyword(s):  
Supply Chain ◽  
Mean Value ◽  
Inventory Level ◽  
Fish Products ◽  
Content Type ◽  
Total Cost ◽  
Holding Cost ◽  
The Cost ◽  
Change In Mean ◽  
Fish Marketing

PurposeThis research formulated to obtain the optimum ordered quantity and optimum inventory range of fish products under the conditions: (1) fully back ordered (lockdown) and (2) partial back ordered (normal geographical market). In both the cases, due to the deterioration nature and in quarantine situation some vendors are not able to satisfy the customers (retailers). So in this model, the cost of penalty is introduced in quarantine time to obtain the optimal total cost.Design/methodology/approachTo find the total cost, holding cost, shortage cost and deterioration cost have to be considered. There are so many disadvantages in holding the deteriorating food products. Due to the demand and deterioration, the holding cost of the fish products is determined. The supply chain of fish marketing process to find the optimum total cost and optimum back ordered quantity in the two situations, namely, (1) normal backordering and (2) Quarantine period is explained.FindingsThe conclusion of this research is exhibited for the uncertain lockdown situation and the normal geographical markets. But in both the cases, the demand function is dependent on the backorder quantity. The expected total cost of the retailers of fish products increased at the least possible range with the increase in the shortage parameter, cost of penalty and variance. But the change in mean value leads to decreasing in the back ordered quantity, inventory level and the annual total cost of the retailers. This analysis contributes to the service of supply chain from wholesaler to retailer in high level.Research limitations/implicationsFish products are very essential for nourishment and economic spread in India. This study has spotlight the efficient method for reducing the total cost of the retailers of fish marketing. The cost of deterioration of fish is high because of its perishable nature. Due to lockdown situation, the holding cost of the fish products depends upon the backordered quantity of geographical market of fish.Practical implicationsThis research formulated to obtain the optimum ordered quantity and optimum inventory range of fish products under the conditions: (1) fully back ordered (lockdown) and (2) partial back ordered (normal geographical market).Social implicationsDue to lockdown situation, the holding cost of the fish products depends upon the backordered quantity of geographical market of fish. This research formulated to obtain the optimum ordered quantity and optimum inventory range of fish products.Originality/valueThis research formulated to obtain the optimum ordered quantity and optimum inventory range of fish products under the conditions: (1) fully back ordered (lockdown) and (2) partial back ordered (normal geographical market). In both the cases, due to the deterioration nature and in quarantine situation some vendors are not able to satisfy the customers (retailers). So in this model, the cost of penalty is introduced in quarantine time to obtain the optimal total cost. A few number of sensitivity analysis are carried out for deterioration rate, shortage parameter and cost of penalty to indicate the existence of total cost in the least possible range.

The cost-effectiveness of insulin analogs and regular insulin for diabetes control: a case study in Iran

2020 ◽  
Vol 33 (4/5) ◽  
pp. 323-331
Author(s):  
Mohsen pakdaman ◽  
Raheleh akbari ◽  
Hamid reza Dehghan ◽  
Asra Asgharzadeh ◽  
Mahdieh Namayandeh
Keyword(s):  
Cost Effectiveness ◽  
Cost Effective ◽  
Regular Insulin ◽  
Diabetes Control ◽  
Diabetic Patients ◽  
Insulin Analogs ◽  
Content Type ◽  
Patients With Diabetes ◽  
The Government ◽  
The Cost

PurposeFor years, traditional techniques have been used for diabetes treatment. There are two major types of insulin: insulin analogs and regular insulin. Insulin analogs are similar to regular insulin and lead to changes in pharmacokinetic and pharmacodynamic properties. The purpose of the present research was to determine the cost-effectiveness of insulin analogs versus regular insulin for diabetes control in Yazd Diabetes Center in 2017.Design/methodology/approachIn this descriptive–analytical research, the cost-effectiveness index was used to compare insulin analogs and regular insulin (pen/vial) for treatment of diabetes. Data were analyzed in the TreeAge Software and a decision tree was constructed. A 10% discount rate was used for ICER sensitivity analysis. Cost-effectiveness was examined from a provider's perspective.FindingsQALY was calculated to be 0.2 for diabetic patients using insulin analogs and 0.05 for those using regular insulin. The average cost was $3.228 for analog users and $1.826 for regular insulin users. An ICER of $0.093506/QALY was obtained. The present findings suggest that insulin analogs are more cost-effective than regular insulin.Originality/valueThis study was conducted using a cost-effectiveness analysis to evaluate insulin analogs versus regular insulin in controlling diabetes. The results of study are helpful to the government to allocate more resources to apply the cost-effective method of the treatment and to protect patients with diabetes from the high cost of treatment.

Evaluating the cost and benefits of earthquake protection of buildings

2018 ◽  
Vol 11 (2) ◽  
pp. 263-278 ◽  
Author(s):  
Benedetto Manganelli ◽  
Marco Vona ◽  
Pierfrancesco De Paola
Keyword(s):  
Real Estate ◽  
Seismic Risk ◽  
Risk Mitigation ◽  
Tax Incentives ◽  
Seismic Retrofitting ◽  
Content Type ◽  
Seismic Risk Mitigation ◽  
The Cost ◽  
Earthquake Protection ◽  
Real Estate Assets

Purpose The purpose of this study is the evaluation of the cost and benefits of earthquake protection of buildings to verify whether the legislative push, through tax incentives, will produce results and lead to a redevelopment of private real estate assets. Design/methodology/approach Through contingent valuation, this research aims to measure the propensity of homeowners to invest in the seismic security of their properties. The sample of homeowners was selected in a southern Italy city, which was characterized by a medium-high seismic hazard. The willingness to pay, once made independent from the family income, was compared with the actual cost of a seismic retrofitting technique to assess its cost-effectiveness. Findings The analysis developed on an example case shows that the economic sustainability of the intervention is only verified when considering the current tax incentives for this type of intervention. Practical implications Choosing to introduce a system to compulsory insurance against seismic risk could certainly be a strong incentive for the implementation of retrofitting interventions on private real estate assets. In this direction, investigations like this can be fundamental to establish the fair risk premium. Originality/value The need for effective seismic risk mitigation policies is also based on the growing awareness of the, often fatal, effects of seismic events, emphasized by the recent medium and high intensity events that hit Italy. The issue of the security of residential buildings is therefore a very topical issue in view of their high seismic vulnerability and the vast number of buildings requiring major seismic retrofitting. Therefore, the propensity of owners to intervene in improving the seismic performance of their properties can be crucial in seismic risk mitigation.

The impact of labor freedom on geographic cost of living differentials

2017 ◽  
Vol 6 (3) ◽  
pp. 385-395
Author(s):  
Richard Cebula ◽  
James E. Payne ◽  
Donnie Horner ◽  
Robert Boylan
Keyword(s):  
Labor Market ◽  
State Level ◽  
The State ◽  
Annual Data ◽  
Significant Finding ◽  
Cost Of Living ◽  
Content Type ◽  
The Usa ◽  
The Cost ◽  
The Impact

Purpose The purpose of this paper is to examine the impact of labor market freedom on state-level cost of living differentials in the USA using cross-sectional data for 2016 after allowing for the impacts of economic and quality of life factors. Design/methodology/approach The study uses two-stage least squares estimation controlling for factors contributing to cost of living differences across states. Findings The results reveal that an increase in labor market freedom reduces the overall cost of living. Research limitations/implications The study can be extended using panel data and alternative measures of labor market freedom. Practical implications In general, the finding that less intrusive government and greater labor freedom are associated with a reduced cost of living should not be surprising. This is because less government intrusion and greater labor freedom both inherently allow markets to be more efficient in the rationalization of and interplay with forces of supply and demand. Social implications The findings of this and future related studies could prove very useful to policy makers and entrepreneurs, as well as small business owners and public corporations of all sizes – particularly those considering either location in, relocation to, or expansion into other markets within the USA. Furthermore, the potential benefits of the National Right-to-Work Law currently under consideration in Congress could add cost of living reductions to the debate. Originality/value The authors extend the literature on cost of living differentials by investigating whether higher amounts of state-level labor market freedom act to reduce the states’ cost of living using the most recent annual data available (2016). That labor freedom has a systemic efficiency impact on the state-level cost of living is a significant finding. In our opinion, it is likely that labor market freedom is increasing the efficiency of labor market transactions in the production and distribution of goods and services, and acts to reduce the cost of living in states. In addition, unlike previous related studies, the authors investigate the impact of not only overall labor market freedom on the state-level cost of living, but also how the three sub-indices of labor market freedom, as identified and measured by Stansel et al. (2014, 2015), impact the cost of living state by state.

A new index to measure cost of living for expatriates in cities

2018 ◽  
Vol 28 (3) ◽  
pp. 295-317
Author(s):  
Khee Giap Tan ◽  
Nguyen Trieu Duong Luu ◽  
Le Phuong Anh Nguyen
Keyword(s):  
New York ◽  
Hong Kong ◽  
Quality Data ◽  
Cost Of Living ◽  
Content Type ◽  
Goods And Services ◽  
Commercial Research ◽  
The Cost ◽  
Cost Of Living Index ◽  
The City

Purpose Cost of living is an important consideration for the decision-making of expatriates and investment decisions of businesses. As competition between cities for talent and capital becomes global instead of national, the need for timely and internationally comparable information on global cities’ cost of living increases. While commercial research houses frequently publish cost of living surveys, these reports can be lacking in terms of scientific rigour. In this context, this paper aims to contribute to the literature by formulating a comprehensive and rigorous methodology to compare the cost of living for expatriates in 103 world’s major cities. Design/methodology/approach A cost of living index for expatriates composed of the ten consumption categories is constructed. The results from the study covers a study period from 2005 to 2014 in 103 cities. More than 280 individual prices of 165 goods and services have been compiled for each city in the calculation of the cost of living index for expatriates. New York has been chosen as the base city for the study, with other cities being benchmarked against it. A larger cost of living index for expatriates implies that the city is more expensive for expatriates to live in and vice versa. Findings While the authors generate the cost of living rankings for expatriates for 103 cities worldwide, in this paper, the authors focus on five key cities, namely, London, Hong Kong, Singapore, Tokyo and Zurich, as they are global financial centres. In 2013, the latest year for which data are available, Zurich was the most expensive for expatriates among the five cities, followed by Singapore, Tokyo, London and Hong Kong. These results pertain to the cost of living for expatriates, and cities compare very differently in terms of cost of living for ordinary residents, as ordinary residents follow different consumption patterns from expatriates. Originality/value Cost of living in the destination city is a major consideration for professionals who look to relocate, and organisations factor such calculations in their decisions to post employees overseas and design commensurate compensation packages. This paper develops a comprehensive and rigorous methodology for measuring and comparing cost of living for expatriates around the world. The value-addition lies in the fact that the authors are able to differentiate between expatriates and ordinary residents, which has not been done in the existing literature. They use higher quality data and generate an index that is not sensitive to the choice of base city.

scholarly journals Evaluation of StrepBSelectChromogenic Medium and the Fast-Track Diagnostics Group B Streptococcus (GBS) Real-Time PCR Assay Compared to Routine Culture for Detection of GBS during Antepartum Screening

2017 ◽  
Vol 55 (7) ◽  
pp. 2137-2142 ◽  
Author(s):  
Deirdre L. Church ◽  
Heather Baxter ◽  
Tracie Lloyd ◽  
Oscar Larios ◽  
Daniel B. Gregson
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Fast Track ◽  
Group B Streptococcus ◽  
Culture Method ◽  
Predictive Values ◽  
Content Type ◽  
Standard Culture ◽  
Group B ◽  
The Cost

ABSTRACTLife-threatening infection in neonates due to group BStreptococcus(GBS) is preventable by screening of near-term pregnant women and treatment at delivery. A total of 295 vaginal-rectal swabs were collected from women attending antepartum clinics in Calgary, Alberta, Canada. GBS colonization was detected by the standard culture method (Strep B Carrot Broth subcultured to blood agar with a neomycin disk) and compared to recovery with Strep Group B Broth (Dalynn Biologicals) subcultured to StrepBSelectchromogenic medium (CM; Bio-Rad Laboratories) and the Fast-Track Diagnostics GBS real-time PCR (quantitative PCR [qPCR]) assay (Phoenix Airmid Biomedical Corp.) performed with broth-enriched samples and the Abbottm2000sp/m2000rt system. A total of 62/295 (21%) women were colonized with GBS; 58 (19.7%) cases were detected by standard culture, while CM and qPCR each found 61 (20.7%) cases. The qPCR and CM were similar in performance, with sensitivities, specificities, and positive and negative predictive values of 98.4 and 98.4%, 99.6 and 99.6%, 98.4 and 98.4%, and 99.6 and 99.6%, respectively, compared to routine culture. Both qPCR and CM would allow more rapid reporting of routine GBS screening results than standard culture. Although the cost per test was similar for standard culture and CM, the routine use of qPCR would cost approximately four times as much as culture-based detection. Laboratories worldwide should consider implementing one of the newer methods for primary GBS testing, depending on the cost limitations of different health care jurisdictions.

Cost effectiveness in palliative care setting

2018 ◽  
Vol 21 (2) ◽  
pp. 62-71
Author(s):  
Henry O’Lawrence ◽  
Rohan Chowlkar
Keyword(s):  
Quality Of Life ◽  
Palliative Care ◽  
End Of Life ◽  
Hospice Care ◽  
Home Health ◽  
Data Set ◽  
Content Type ◽  
Care Services ◽  
The Cost

Purpose The purpose of this paper is to determine the cost effectiveness of palliative care on patients in a home health and hospice setting. Secondary data set was utilized to test the hypotheses of this study. Home health care and hospice care services have the potential to avert hospital admissions in patients requiring palliative care, which significantly affects medicare spending. With the aging population, it has become evident that demand of palliative care will increase four-fold. It was determined that current spending on end-of-life care is radically emptying medicare funds and fiscally weakening numerous families who have patients under palliative care during life-threatening illnesses. The study found that a majority of people registering for palliative and hospice care settings are above the age group of 55 years old. Design/methodology/approach Different variables like length of stay, mode of payment and disease diagnosis were used to filter the available data set. Secondary data were utilized to test the hypothesis of this study. There are very few studies on hospice and palliative care services and no study focuses on the cost associated with this care. Since a very large number of the USA, population is turning 65 and over, it is very important to analyze the cost of care for palliative and hospice care. For the purpose of this analysis, data were utilized from the National Home and Hospice Care Survey (NHHCS), which has been conducted periodically by the Centers for Disease Control and Prevention’s National Center for Health Statistics. Descriptive statistics, χ2 tests and t-tests were used to test for statistical significance at the p<0.05 level. Findings The Statistical Package for Social Sciences (SPSS) was utilized for this result. H1 predicted that patients in the age group of 65 years and up have the highest utilization of home and hospice care. This study examined various demographic variables in hospice and home health care which may help to evaluate the cost of care and the modes of payments. This section of the result presents the descriptive analysis of dependent, independent and covariate variables that provide the overall national estimates on differences in use of home and hospice care in various age groups and sex. Research limitations/implications The data set used was from the 2007 NHHCS survey, no data have been collected thereafter, and therefore, gap in data analysis may give inaccurate findings. To compensate for this gap in the data set, recent studies were reviewed which analyzed cost in palliative care in the USA. There has been a lack of evidence to prove the cost savings and improved quality of life in palliative/hospice care. There is a need for new research on the various cost factors affecting palliative care services as well as considering the quality of life. Although, it is evident that palliative care treatment is less expensive as compared to the regular care, since it eliminates the direct hospitalization cost, but there is inadequate research to prove that it improves the quality of life. A detailed research is required considering the additional cost incurred in palliative/hospice care services and a cost-benefit analysis of the same. Practical implications While various studies reporting information applicable to the expenses and effect of family caregiving toward the end-of-life were distinguished, none of the previous research discussed this issue as their central focus. Most studies addressed more extensive financial effect of palliative and end-of-life care, including expenses borne by the patients themselves, the medicinal services framework and safety net providers or beneficent/willful suppliers. This shows a significant hole in the current writing. Social implications With the aging population, it has become evident that demand of palliative/hospice care will increase four-fold. The NHHCS have stopped keeping track of the palliative care requirements after 2007, which has a negative impact on the growing needs. Cost analysis can only be performed by analyzing existing data. This review has recognized a huge niche in the evidence base with respect to the cost cares of giving care and supporting a relative inside a palliative/hospice care setting. Originality/value The study exhibited that cost diminishments in aggressive medications can take care of the expenses of palliative/hospice care services. The issue of evaluating result in such a physically measurable way is complicated by the impalpable nature of large portions of the individual components of outcome. Although physical and mental well-being can be evaluated to a certain degree, it is significantly more difficult to gauge in a quantifiable way, the social and profound measurements of care that help fundamentally to general quality of care.

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