The purpose of this paper is to illustrate an uncertain programming model for scheduling of preventive maintenance (PM) actions. The PM scheduling, in which PM actions are…
Abstract
Purpose
The purpose of this paper is to illustrate an uncertain programming model for scheduling of preventive maintenance (PM) actions. The PM scheduling, in which PM actions are performed under fixed intervals, is solved by grey systems theory.
Design/methodology/approach
The paper applied the grey evaluation method based on triangular whitenization weight functions which includes two classes: endpoint evaluation method and center-point evaluation method.
Findings
Two methods give the same results based on endpoint and center-point triangular whitenization weight functions. For validation, the results were compared by Cassady’s method.
Originality/value
The scheduling of PM is crucial in reliability and maintenance engineering. Hundreds of parts compose complex machines that require replacement and/or repairing. It is helpful to reduce the outage loss on frequent repair/replacement parts and avoid lack of maintenance of the equipment by controlling the equipment maintenance frequency.
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Hamed Maleki and Mohammad Taghi Taghavi Fard
The time required for a certain task to be performed normally reduces on its frequent completion, as more units are produced over time, it is expected to have an increase in the…
Abstract
Purpose
The time required for a certain task to be performed normally reduces on its frequent completion, as more units are produced over time, it is expected to have an increase in the total worker’s output performance. Learning curve (LC) is a mathematical representation to estimate the time of tasks which occurs repeatedly. The parameter prediction is considered a major disadvantage from which LC suffers. The purpose of this paper is to investigate grey systems theory as a method for the standard time.
Design/methodology/approach
The proposed method starts with data which are obtained by traditional time study and then, models LC for an assembling activity of Electrogen Company. The paper studies the grey evaluation method based on triangular whitenization weight functions which includes two classes: endpoint triangular whitenization functions and center-point triangular whitenization functions. The grey system results are compared with those of the LC.
Findings
The results show that the standard time given by grey systems theory is closer than the standard time given by LC to standard time with 100 per cent performance level.
Originality/value
Scheduling problems are complex and uncertain, and it is very rare for such systems to be exactly determined in all their complexity. According to grey systems theory, the job processing time can be considered as the object that extension is definite but intension is uncertain. Consequently, grey systems theory with its focus on the uncertainty problems of small samples and incomplete information is proposed in the paper.
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Seyed Hadi Arabi, Mohammad Hasan Maleki and Hamed Ansari
The purpose of this study is to identify the drivers and future scenarios of Iran’s Social Security Organization.
Abstract
Purpose
The purpose of this study is to identify the drivers and future scenarios of Iran’s Social Security Organization.
Design/methodology/approach
The research is applied in terms of orientation and mixed in terms of methodology. In this research, the methods of theme analysis, root definitions, fuzzy Delphi and Cocoso were used. The theoretical population is the managers and senior experts of the social security organization, and the sampling method was done in a judgmental way. The tools of data collection were interviews and questionnaires. The interview tool was used to extract the main and subdrivers of the research and develop the scenarios.
Findings
Through theme analysis, 35 subdrivers were extracted in the form of economic, sociocultural, financial and investment, policy, marketing, environmental and legal themes. Due to the large number of subdrivers, these factors were screened with fuzzy Delphi. Eleven drivers had defuzzied coefficient higher than 0.7 and were selected for final prioritization. The final drivers were prioritized with the CoCoSo technique, and the two drivers of social security holdings governance and state of government revenues had the highest priority. Based on these two drivers, four scenarios of prosperity, resilient social security, unstable development and collapse have been developed.
Originality/value
Some of the suggestions of the research are: using the capacity of FinTechs and financial startups to invest the government revenues of the organization, using digital technologies such as business intelligence for more efficient decisions and developing corporate governance in the organization.
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Sahar Tadayonirad, Hany Seidgar, Hamed Fazlollahtabar and Rasoul Shafaei
In real manufacturing systems, schedules are often disrupted with uncertainty factors such as random machine breakdown, random process time, random job arrivals or job…
Abstract
Purpose
In real manufacturing systems, schedules are often disrupted with uncertainty factors such as random machine breakdown, random process time, random job arrivals or job cancellations. This paper aims to investigate robust scheduling for a two-stage assembly flow shop scheduling with random machine breakdowns and considers two objectives makespan and robustness simultaneously.
Design/methodology/approach
Owing to its structural and algorithmic complexity, the authors proposed imperialist competitive algorithm (ICA), genetic algorithm (GA) and hybridized with simulation techniques for handling these complexities. For better efficiency of the proposed algorithms, the authors used artificial neural network (ANN) to predict the parameters of the proposed algorithms in uncertain condition. Also Taguchi method is applied for analyzing the effect of the parameters of the problem on each other and quality of solutions.
Findings
Finally, experimental study and analysis of variance (ANOVA) is done to investigate the effect of different proposed measures on the performance of the obtained results. ANOVA's results indicate the job and weight of makespan factors have a significant impact on the robustness of the proposed meta-heuristics algorithms. Also, it is obvious that the most effective parameter on the robustness for GA and ICA is job.
Originality/value
Robustness is calculated by the expected value of the relative difference between the deterministic and actual makespan.
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Amin Houari, Madani Kouider, Alper Polat, Salah Amroune, Barhm Abdullah Mohamad, Ahmed Chellil and Raul Campilho
The purpose of this research is to evaluate the effectiveness of different repair patch materials in reducing the stresses at the crack tip of a 2024-T3 aluminum plate. This…
Abstract
Purpose
The purpose of this research is to evaluate the effectiveness of different repair patch materials in reducing the stresses at the crack tip of a 2024-T3 aluminum plate. This involves a numerical analysis using the finite element method (FEM) to estimate the reduction in the J-integral value, with the goal of identifying how various parameters related to the patch materials, adhesive properties and loading conditions influence the structural integrity of the repaired plate.
Design/methodology/approach
The methodology of this research involves conducting a numerical analysis using the FEM to estimate the reduction in the J-integral value at the crack tip of a 2024-T3 aluminum plate. Three types of patches – metal, composite and functionally graded material (FGM) – were examined under tensile loading conditions, and Adekit-A140 adhesive was used to bond these repair patches to the aluminum plate.
Findings
The analysis considered various parameters, including crack length, the nature of fibers in the composite material, the gradation exponent for FGM patches and the nature of the face in contact with the adhesive for the FGM patch. Additionally, stress analysis was conducted, examining the J-integral values for the plate, shear stress in the adhesive layer and peel stress in the composite patch. The findings highlight that modifying the nature of the repair patch used can significantly enhance the structural integrity of the repaired plate.
Originality/value
The study analyzed J-integral values, shear stress in the adhesive and peel stress in the composite patch. Various parameters, including crack length, fiber type, gradation exponent and adhesive contact face nature, were considered. Results demonstrate that the J-integral value can be significantly reduced by altering the repair patch type, highlighting the effectiveness of customized patch materials in enhancing structural integrity.
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Fatih Selimefendigil and Hakan F. Oztop
This study aims to examine the effects of cross-flow and multiple jet impingement on conductive panel cooling performance when subjected to uniform magnetic field effects. The…
Abstract
Purpose
This study aims to examine the effects of cross-flow and multiple jet impingement on conductive panel cooling performance when subjected to uniform magnetic field effects. The cooling system has double rotating cylinders.
Design/methodology/approach
Cross-flow ratios (CFR) ranging from 0.1 to 1, magnetic field strength (Ha) ranging from 0 to 50 and cylinder rotation speed (Rew) ranging from −5,000 to 5,000 are the relevant parameters that are included in the numerical analysis. Finite element method is used as solution technique. Radial basis networks are used for the prediction of average Nusselt number (Nu), average surface temperature of the panel and temperature uniformity effects when varying the impacts of cross-flow, magnetic field and rotations of the double cylinder in the cooling channel.
Findings
The effect of CFR on cooling efficiency and temperature uniformity is favorable. By raising the CFR to the highest value under the magnetic field, the average Nu can rise by up to 18.6%, while the temperature drop and temperature difference are obtained as 1.87°C and 3.72°C. Without cylinders, magnetic field improves the cooling performance, while average Nu increases to 4.5% and 8.8% at CR = 0.1 and CR = 1, respectively. When the magnetic field is the strongest with cylinders in channel at CFR = 1, temperature difference (ΔT) is obtained as 2.5 °C. The rotational impacts on thermal performance are more significant when the cross-flow effects are weak (CFR = 0.1) compared to when they are substantial (CFR = 1). Cases without a cylinder have the worst performance for both weak and severe cross-flow effects, whereas using two rotating cylinders increases cooling performance and temperature uniformity for the conductive panel. The average surface temperature lowers by 1.2°C at CFR = 0.1 and 0.5°C at CFR = 1 when the worst and best situations are compared.
Originality/value
The outcomes are relevant in the design and optimization-based studies for electric cooling, photo-voltaic cooling and battery thermal management.
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Hamed Gheibdoust and Mehdi Jabbari Zideh
Nowadays, the electricity supply chain is significant for most societies, so it is necessary to use new technologies such as blockchain in the electricity industry. This study…
Abstract
Purpose
Nowadays, the electricity supply chain is significant for most societies, so it is necessary to use new technologies such as blockchain in the electricity industry. This study aims to identify and prioritize the factors influencing the adoption of blockchain technology in the electricity supply chain of the US.
Design/methodology/approach
In this study, after reviewing the research literature, the influential factors of blockchain adoption in the electricity industry are identified and the consensus of the experts is reached. Experts have a thorough understanding of blockchain technology and the US electricity industry. Data is collected using a Step-Wise Weight Assessment Ratio Analysis (SWARA) questionnaire from November 2022 to July 2023. Using the SWARA questionnaire, experts compared 16 influential subcriteria of blockchain adoption. Then, using the Fuzzy SWARA method, the following influential subcriteria of blockchain adaptation in the US electricity industry are evaluated and prioritized.
Findings
The results show that the most significant subcriterion among the 16 influential subcriteria for the adoption of blockchain technology in the electricity supply chain is reducing cost, whereas the collaborating with supply chain partners subcriterion is recognized as the least important subcriterion.
Originality/value
The present study helps managers improve their knowledge to apply blockchain technology and also have the best performance for applying blockchain technology in the electricity supply chain.
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Amir Asgharian, Reza Yadipour, Gholamreza Kiani and Hamed Baghban
The purpose of this study is to design a plasmonic structure that can be used simultaneously as a heater and a refractive index sensor applicable for heating and sensing cycles of…
Abstract
Purpose
The purpose of this study is to design a plasmonic structure that can be used simultaneously as a heater and a refractive index sensor applicable for heating and sensing cycles of lab-on-chip (LOC).
Design/methodology/approach
The authors report on the full optical method applicable in the heating and sensing cycles of LOC based on the plasmonic nanostructure. The novelty of this proposed structure is due to the fact that a structure simultaneously acts as a heater and a sensor.
Findings
In terms of the performance of the proposed structure as an analyte detection sensor, in addition to the real-time measurement, there is no need to labeling the sample. In terms of the performance of the proposed structure as a plasmonic heater, the uniformity and speed of the heating and cooling cycles have been greatly improved. Also, there is no need for experts and laboratory conditions; therefore, our proposed method can meet the conditions of point of care testing.
Originality/value
The authors confirm that this work is original and has not been published elsewhere nor it is currently under consideration for publication elsewhere.
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Ibrahim Inyass Adamu, Taofeek Tunde Okanlawon, Luqman Oyekunle Oyewobi, Abdullateef Adewale Shittu and Richard Ajayi Jimoh
This paper evaluates the benefits of harnessing artificial intelligence (AI) tools for safety compliance on construction projects in Nigeria.
Abstract
Purpose
This paper evaluates the benefits of harnessing artificial intelligence (AI) tools for safety compliance on construction projects in Nigeria.
Design/methodology/approach
This study employed a specialised approach by combining qualitative and quantitative approach. The study carried out a brief systematic literature review (SLR) to identify the variables of the study. These variables were prepared in a questionnaire which was distributed among professionals within the Nigerian construction sector using purposive sampling. A total of 140 questionnaires were retrieved. The collected data were analysed using Relative Importance Index (RII), Ginni’s Mean (GM) and exploratory factor analysis (EFA).
Findings
The analysis revealed that all the identified benefits hold considerable importance, with an average RII of 0.86, with real-time monitoring as the most prominent advantage. However, using the GM which was 0.861, the study identified “mitigation of hazards on worksites” as the stationary benefit of AI in safety compliance.
Research limitations/implications
The study was conducted exclusively within Nigeria’s Federal Capital Territory, using a cross-sectional survey approach.
Practical implications
The results will be valuable for professionals and practitioners in the Nigerian construction sector, as they will acquire insights into the potential advantages of utilising AI tools for monitoring of safety compliance on construction projects.
Originality/value
The study adopted a robust approach by identifying the stationary benefit using the GM in combination with RII and EFA.
Details
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Rajni Bala, Sandeep Singh and Kulwant Kumar Sharma
Environment-friendly behaviour is essential for a sustainable development. The study is an attempt to fill the research gap by analysing the mediating role of environmental…
Abstract
Purpose
Environment-friendly behaviour is essential for a sustainable development. The study is an attempt to fill the research gap by analysing the mediating role of environmental sensitivity (ES) and environmental attitude (EA) on the relationship between environmental knowledge (EK) and environmental behavioural intention (EBI). It aims to investigate the direct as well as indirect relationship between EK, ES, EA and EBI.
Design/methodology/approach
The data were collected from 466 university students representing northern region of India. The use of purposive sampling technique helped to reach the maximum number of respondents. The hypothesis was tested by applying partial least square structural equation modelling (PLS-SEM).
Findings
It was found that the relationship between EK and EBI was sequentially mediated by ES and EA. The study provides a model which would be instrumental in protecting the environment. It describes how the behaviour intentions of youth come into existence from EK.
Practical implications
The study is quite useful for making training schedules regarding environment protection specifically for the students. The study has various implications for the society as well. As the young students are a significant part of the society, the social communities can use this model to understand the various needs of the youth. It is likely to provide additional EK to the youth. The tested model explains how EK converts into EBI. The government and non-government agencies can use the model for chalking out environment protection strategy at the local as well as national level.
Originality/value
It is believed that this is the first study of its kind which highlights the causal links between EK, ES, EA and EBI. No doubt, certain studies were conducted by ascertaining the relationship between two or three of these variables, but none provided an insight into the direct and indirect relationship between these variables.