M.K. Loganathan and O.P. Gandhi
Reliability assessment does require an effective structural modelling approach for systems, in general and manufacturing systems are no exception. This paper aims to develop it…
Abstract
Purpose
Reliability assessment does require an effective structural modelling approach for systems, in general and manufacturing systems are no exception. This paper aims to develop it for large manufacturing systems using graph models, a systems approach.
Design/methodology/approach
Structural graph models for reliability at various hierarchical levels are developed by considering a CNC cam shaft grinding machine. The system reliability expression is obtained by converting the reliability graphs into equivalent matrices, which helps to evaluate and analyse system.
Findings
Using the obtained reliability expressions at various hierarchical levels of the system, it is possible not only to evaluate its reliability from structure point of view but also to identify weak structural elements from reliability point of view.
Research limitations/implications
The approach can be extended to include the influence of other parameters, such as human, component and environment, etc., on the system reliability.
Practical implications
The approach helps to design and develop manufacturing systems from reliability consideration by assessing their possible alternatives among these.
Originality/value
The suggested methodology is useful for reliability evaluation of large and complex manufacturing systems.
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A method for qualitative estimation of reliability of large and complex mechanical and hydraulic systems is presented. It is especially useful for comparison and optimum selection…
Abstract
A method for qualitative estimation of reliability of large and complex mechanical and hydraulic systems is presented. It is especially useful for comparison and optimum selection of the structure at the conceptual stage of design when no other information about the salient features or parameters of the system is known. The method permits the identification and analysis of critical paths, loops and subsystems causing failure under different causes and modes. The method is based on graph theory and the graph variants proposed as reliability measures are also modified to yield realistic and useful results. The concept of system graph introduced in the article for dealing with large systems appears to be the most appropriate for analysis, comparison, selection and reliability estimates at the beginning of the system′s design.
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Ajith Tom James, O.P. Gandhi and S.G. Deshmukh
The purpose of this paper is to develop an ontological model of failure knowledge of automobile systems that will enhance the knowledge management of automobile system failures…
Abstract
Purpose
The purpose of this paper is to develop an ontological model of failure knowledge of automobile systems that will enhance the knowledge management of automobile system failures, which will help for design and maintenance of automobiles. Failure knowledge of automobile systems and components gained through maintenance and repair can mitigate future failures, if integrated in the design. This is an outcome of this paper.
Design/methodology/approach
A failure coding scheme is developed for assimilating various entities of automobile failure knowledge and an ontological model is developed for its systematic structuring and representation. The developed failure code is a combination of alphanumeric and numeric code that incorporates ingredients of the failure knowledge, which will help database management, with reduced data entry time and storage space.
Findings
The maintenance of automobiles not only brings back the systems into operating conditions but also convey a lot of information regarding the failures. This is a useful input to the designers in development of reliable and maintainable automobile systems. A knowledge base can be created for automobile systems/components failures from their maintenance and service experience.
Research limitations/implications
Developed ontological model of automobile failure knowledge gained through maintenance experience can be shared across automobile manufacturers and service providers. This would help in design improvements, with ease and efficient undertaking of maintenance activities. This paper proposes the conceptual ontology structure, which is populated with three cases of automobile maintenance.
Originality/value
This research work is a first attempt to develop an ontological model for automobile failures from their maintenance and service experience. The novelty of the work is in its explicit consideration of all knowledge related to failures and maintenance of automobile systems, with their coding and structuring.
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The purpose of this paper is to evaluate and analyze lube oil performance. The plant experience shows that the oil, even after completion of a number of hours of recommended…
Abstract
Purpose
The purpose of this paper is to evaluate and analyze lube oil performance. The plant experience shows that the oil, even after completion of a number of hours of recommended operation, has some residual life. It is desirable to maximize its use to conserve this scarce resource but avoid failures. At present, continuation or change of the oil is decided, based on the manufacturer's recommendation and experience in the plant. The suggested oil change period is conservative and results in non‐efficient usage of oil. This practice needs refinement to include all possible properties/attributes of oil and use of appropriate procedure to assess its realistic performance.
Design/methodology/approach
Parameter profile approach (PPA) is applied to evaluate and analyze the lubricating oil performance parameters.
Findings
Physical and chemical properties related to degradation of the lube oil are considered as lubricating oil performance parameters. The value of these performance parameters from time to time, obtained by analyzing samples drawn from the system, are analyzed through PPA. In this approach, mean, median, performance parameter index and time performance index are defined and evaluated at different time intervals. The suggested procedure is illustrated by means of an example.
Originality/value
The suggested procedure will be helpful for the maintenance personnel in planned oil replacement, and in identifying the weak oil properties in respect of the identified lube oil performance parameters.
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Nor Zaimah Che-Ghani, Nik Elyna Myeda and Azlan Shah Ali
To achieve efficient operation and maintenance (O&M) management, this study seeks to identify critical success factors (CSFs) affecting service delivery factors of O&M services at…
Abstract
Purpose
To achieve efficient operation and maintenance (O&M) management, this study seeks to identify critical success factors (CSFs) affecting service delivery factors of O&M services at stratified residential buildings. The purpose of this study is to yield measurable data for developing an effective O&M framework to enhancing its performance. In future research, this study will further investigate the relationship between the CSF and service performance factors.
Design/methodology/approach
This study adopts a combination of qualitative and quantitative techniques that yields conclusive study findings while improving the research’s validity and dependability. Two series of instruments were conducted in an effort to refine the efficient O&M framework variables. Instruments used in addressing the research gap were a questionnaire survey and focus group discussion (FGD). Analysis of data was completed via the Statistical Package for the Social Sciences (SPSS) programme for quantitative data and thematic analysis for qualitative data.
Findings
This study concludes that the CSFs directly affect the performance of O&M. Questionnaire survey and FGD findings have refined the CSF into three main categories, namely, building characteristics, O&M management and community participation. FGD experts further suggested that service performance factors can be measured against SERVQUAL service qualities such as reliability, tangible, responsiveness, assurance and empathy.
Research limitations/implications
Future research may consider the inclusion of financial elements in the O&M service delivery.
Originality/value
This study presents a fresh insight into the CSFs that construct an efficient O&M framework through rigorous steps of data collection and analysis. This study proposes impactful guidance for policymakers, practitioners and residents on the significance of all parties’ involvement to support the management of residential buildings, where the current practice of O&M constantly faces complex issues. This study derives novice strategies that should correspond to the growing issues and challenges in managing residential buildings. The deeper insight into the role of O&M represents a direction for the future development of facilities management progress and stratified residential building sectors.
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Deepak Tiwari, Ahmad Faizan Sherwani, Mohammad Asjad and Akhilesh Arora
The purpose of this paper is to investigate the effect of four controllable parameters (fuel mixture, evaporation bubble point temperature, expander inlet temperature and…
Abstract
Purpose
The purpose of this paper is to investigate the effect of four controllable parameters (fuel mixture, evaporation bubble point temperature, expander inlet temperature and condensation dew point temperature) of a solar-driven organic Rankine cycle (ORC) on the first-law efficiency, the exergetic efficiency, the exergy destruction and the volume flow ratio (expander outlet/expander inlet).
Design/methodology/approach
Nine experiments as per Taguchi’s standard L9 orthogonal array were performed on the solar-driven ORC. Subsequently, multi-response optimization was performed using grey relational and principal component analyses.
Findings
The results revealed that the grey relational analysis along with the principal component analysis is a simple as well as effective method for solving the multi-response optimization problem and it provides the optimal combination of the solar-driven ORC parameters. Further, the analysis of variance was also employed to identify the most significant parameter based on the percentage of contribution of each cyclic parameter. Confirmation tests were performed to check the validity of the results which revealed good agreement between predicted and experimental values of the response variables at optimum combination of the input parameters. The optimal combination of process parameters is the set with A3 (the best fuel mixture in the context of optimal performance is 0.9 percent butane and 0.1 percent pentane by weight), B2 (evaporation bubble point temperature=358 K), C1 (condensation dew point temperature=300 K) and D3 (expander inlet temperature=370 K).
Research limitations/implications
In this research, the Taguchi-based grey relational analysis coupled with the principal components analysis has been successfully carried out, whereas for any optimized solution, it is required to have a real-time scenario that may be taken into consideration by the application of different soft computing techniques like genetic algorithm, simulated annealing, etc. The results generated are purely based on theoretical modeling, and, for further research, experimental analyses are required to consolidate the generated results.
Originality/value
This piece of research work will be helpful to users of solar energy, academicians, researchers and other concerned persons, in understanding the importance, severity and benefits obtained by the application, implementation and optimization of the cyclic parameters of the solar-driven ORC.
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B. Sharma and O.P. Gandhi
Most of the mechanical systems consist of common tribo components such as gear, bearing, seal, pump, etc. During operation, the failure of such a component may lead to failure of…
Abstract
Purpose
Most of the mechanical systems consist of common tribo components such as gear, bearing, seal, pump, etc. During operation, the failure of such a component may lead to failure of the system or any other components depending on the system structure or its connections. The transformation of functional quantities or parameters within and various components make these vulnerable to failures and breakdowns. The main purpose of this paper is to evaluate the reliability of a tribo‐pair during operation based on the operational parameters which takes into account the deviation in functional objective and considers the component structure explicitly.
Design/methodology/approach
Failure representation using digraph models have mainly been limited to chemical systems and processes but have been applied to a limited extent to mechanical systems. Researchers have considered the operating parameters such as pressure, temperature; feed rate, flow, etc. as the input/output operational parameter for failure cause identification of tribo mechanical system. However, these are not true in case of components like gear, bearing, etc. Therefore, this methodology has been refined in this paper, and is extended to a tribo‐pair by considering its functions along with operating parameters for reliability assessment. The tribo‐pair considered for the development of model is a gear pair, which is a common and important example of mechanical components.
Findings
Understanding of the failure modes helps the designer in identifying the root cause of failure and the operational parameters whose increase/decrease affects the functional objective. Consideration of the input and output parameters and their interrelations are used to develop input‐output model of a gear pair called gear pair model. This requires consideration of the input and output parameters, which are based on the gear pair functionality. These parameters have been identified. Four input parameters; five output parameters and one condition monitoring parameter are considered to model the gear pair. In addition to input and output parameters condition monitoring parameters are also considered to develop the gear pair model.
Originality/value
Reliability assessment of a tribo‐pair during operation will help the practicing engineers to take corrective action and minimize the occurrence of undesired failure symptom during operation. The decrease in possibility of undesired failure symptom will enhance the reliability of mechanical system.
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M. Asjad, M.S. Kulkarni and O.P. Gandhi
Original equipment manufacturers (OEMs) start providing support to their products, that helped them in beating the competition across the worldwide. The unavailability of spares…
Abstract
Purpose
Original equipment manufacturers (OEMs) start providing support to their products, that helped them in beating the competition across the worldwide. The unavailability of spares and crews may also prolong the downtime of equipment, thereby affecting the systems’ performance. The spares and crews have as much effect on the systems’ performance as the design characteristics (i.e. reliability and maintainability). Thus, the OEMs required to extent the support to their products through maintenance, spares, crews, etc., so as to gain the customer satisfaction.
Design/methodology/approach
The mathematical model for spares, crews and support quality has been presented in this research work. The problem has been identified from the literature perspective for mechanical systems.
Findings
The model has been implemented on a real-life problem, in which the OEMs provide support to their make installed at compressed natural gas workstation in National Capital Region, India.
Originality/value
The research proposed in this work will be helpful to manufacturer, customer, academician, researcher, industrialist and any concerned person, to get the exhaustive benefits from the system.
Details
Keywords
The plant experience shows that the oil even after completion of a number of hours of recommended operation has some residual life. It is desirable to maximize its use to conserve…
Abstract
Purpose
The plant experience shows that the oil even after completion of a number of hours of recommended operation has some residual life. It is desirable to maximize its use to conserve this scarce resource but avoid failures. At present, continuation or change of the oil is decided, based on the manufacturer's recommendation and experience in the plant. The suggested oil change period is conservative and results in non‐efficient usage of oil. This practice needs refinement to include all possible properties/attributes of oil and use of appropriate procedure to assess its realistic performance degradation and determine the remaining useful life (RUL) of lube oil.
Design/methodology/approach
Analytic hierarchy process (AHP), a multi criteria decision‐making method, in conjunction with vector projection approach is applied to assess the remaining useful life of lube oil.
Findings
Physical and chemical properties related to degradation of the lube oil are considered as lubricant attributes and their weights for given application is assigned, using AHP. The value of these attributes from time to time, obtained by testing samples drawn from the system, are analyzed through vector projection approach. In this approach, module, cosine of angle and projection are defined and evaluated at different time intervals. The projection is related to module and cosine of angle and is related to RUL of the lubricant. The suggested procedure is illustrated by means of an example.
Originality/value
The suggested procedure will be helpful for the maintenance personnel in planned oil replacement, with maximum usage of the lube oil but avoiding failures.
Details
Keywords
Mohammad Asjad, Makarand S Kulkarni and O P Gandhi
Original equipment manufacturers (OEMs) start providing support to products that helped them in sustaining their business worldwide. The customers are entering into contracts with…
Abstract
Purpose
Original equipment manufacturers (OEMs) start providing support to products that helped them in sustaining their business worldwide. The customers are entering into contracts with the OEM, to get the required level of performance but at minimum possible cost. It required the work distribution between OEM/service provider and the client, and may formalize through contract. The contract structure depends upon the number of player involved (customer, OEM and third party) and the support activity. The different contract alternatives can be formulated and the best one may be selected on the basis of minimum Life cycle cost. The paper aims to discuss these issues.
Design/methodology/approach
In this work, mathematical models are developed; which are implemented on a real life problem. The developed models are optimized in context to preventive maintenance schedule.
Findings
In this research, important issues are listed; research steps and mathematical models are presented. The problem has been identified from the literature perspective for mechanical systems. A methodology for formulating and selecting the optimal contract structure is also proposed. The model has been implemented on a real life problem, in which the OEMs provide support to their make installed at Compressed Natural Gas workstation in National Capital Region, India.
Originality/value
The research results of this paper will contribute both academic and empirical value.