Papers by siba sankar Mahapatra
International Journal of Industrial and Systems Engineering, 2017
Usually, multi-criteria decision making methods are embedded with design of experiment (DOE) appr... more Usually, multi-criteria decision making methods are embedded with design of experiment (DOE) approach for handling the multi-response optimisation problems. However, uncertainties, impreciseness and arbitrary human judgement for weight assignment to criteria and alternatives result in inferior solutions. To overcome this limitation, an intelligent approach based on neuro-fuzzy system is proposed for converting multi-responses into single equivalent response. To illustrate the superiority of the proposed approach, a complex case study of taper cutting operation using wire electrical discharge machining (WEDM) process is considered. The effect of process parameters on equivalent response has been studied in detail and the relationship between the input parameters and responses are established by means of a nonlinear regression analysis resulting in a valid mathematical model. Finally, optimal parameter setting is obtained by recently proposed meta-heuristics like bat algorithm.
International Journal of Industrial and Systems Engineering, 2017
Drilling of carbon fibre reinforced plastics (CFRPs) is indeed very complicated due to high struc... more Drilling of carbon fibre reinforced plastics (CFRPs) is indeed very complicated due to high structural stiffness of the composite as a whole and low thermal conductivity of plastic matrix. During drilling operation, the tool comes across matrix and reinforcement alternatively which results in destruction of fibre continuity with generation of large stress concentration in the material and delamination at the hole during entry as well as exit. Hence, appropriate selection of drilling process parameters is indeed necessary for achieving efficient machining performance on drilling of CFRP composites. In order to achieve satisfactory product quality characteristics as well as excellent machining performance, the optimisation of machining parameters like drill bit diameter, spindle speed, and feed rate are seemed compulsory. The objective of this paper is to highlight the effect of aforesaid process parameters on thrust force, torque, surface roughness, entry delamination factor and exit delamination factor in drilling of CFRP composites. The optimal setting of the controllable process parameters has been determined through experiments planned and conducted using the Taguchi's philosophy. The application of principal component analysis (PCA) combined with fuzzy inference system (FIS) and finally Taguchi's optimisation methodology in assessing of optimal parameter setting has been discussed in this article.
International Journal of Industrial and Systems Engineering, 2016
In this work, a thermal model based on finite element method has been proposed to predict the mat... more In this work, a thermal model based on finite element method has been proposed to predict the material removal and tool wear in electrical discharge machining process by simulating a single spark discharge. The model is validated by conducting experiments on a die-sinking EDM machine. It is found that numerical model provides reasonably accurate estimation of responses. Parametric analysis is conducted on the proposed model to study the influence of significant process parameters on the responses. Regression analysis is carried out to develop empirical models relating responses with process parameters. Finally, a non-dominated sorting genetic algorithm has been employed to obtain Pareto optimal solution for multi-objective optimisation. The numerical method provides an inexpensive and time saving alternative to study the performance of machining before actual cutting operation.
International Journal of Injury Control and Safety Promotion, 2015
Swarm, Evolutionary, and Memetic Computing, 2015
Present work proposes a thermo-numerical model for accurate prediction of material removal and to... more Present work proposes a thermo-numerical model for accurate prediction of material removal and tool erosion for electrical discharge machining (EDM) process. The data collected for the numerical analysis is based on Box-Behnken’s experimental design, a popular response surface methodology (RSM) approach. The numerical model is validated by comparing experimental results on a die sinking EDM machine. A sequentially coupled thermo-structural model has also been proposed to estimate the residual stress distribution on the work piece. Analysis of variance is conducted to identify significant parameters. Regression analysis is conducted on the model to develop valid mathematical models relating responses with process parameters. Finally, a multi objective particle swam (MOPSO) algorithm has been adopted for simultaneous optimization of responses. The proposed model can be employed for selecting ideal process states to improve process productivity and finishing capabilities.
International Journal of Agile Systems and Management, 2015
The present work reports a case research carried out in an Indian automobile sector in which the ... more The present work reports a case research carried out in an Indian automobile sector in which the supply chain performance index has been measured, from the viewpoint of leanness, agility as well as leagility, separately. In order to evaluate performance extent of individual aspects (lean/agile/leagile) of the organisational supply chain; different criteria hierarchy (evaluation index system for lean, agile and leagile performance estimation) have been considered; a conceptual performance assessment module has been established in conjugation with fuzzy set theory. The fuzzy set theory has been explored to deal with uncertain evaluation information due to variation in human perception in relation to subjective evaluation criteria. Moreover, lean, agile and leagile criterions have been ranked in accordance with their existing performance level. This could help in identifying ill-performing supply chain segments (areas) which require subsequent future improvement to boost up organisational leanness, agility as well as leagility degree.
Benchmarking: An International Journal, 2015
Purpose – Robot selection is one of the critical decision-making tasks frequently performed by va... more Purpose – Robot selection is one of the critical decision-making tasks frequently performed by various industries in order to choose the best suited robot for specific industrial purposes. In recent marketplace, the number of robot manufacturers has increased remarkably offering a wide range of models and specifications; thus, robot selection has become indeed confusing as well as complicated task. Selection of an appropriate robot is a sensitive process; it may result massive letdown, if not chosen properly. Therefore, for unravel the selection problem; the purpose of this paper is to explore the preference ranking organization method for enrichment evaluation (PROMETHEE) II method. Design/methodology/approach – Apart from a large variety of robotic systems, existence of various multi-criteria decision making (MCDM) tools and techniques may create confusion to the decision makers’ in regards of application feasibility as well as superiority in performance to work under different de...
Grey Systems: Theory and Application, 2015
Purpose – Supply chain performance (SCP) extent can be attributed as a function of multiple crite... more Purpose – Supply chain performance (SCP) extent can be attributed as a function of multiple criteria/attributes. Most of the criterions/attributes being intangible in nature; SCP appraisement relies on the subjective judgment of the decision makers. Moreover, quantitative appraisement of SCP appears to be very difficult due to involvement of ill-defined (vague) performance measures as well as metrics. The purpose of this paper is to develop an efficient decision support system (DSS) to facilitate SCP appraisement, benchmarking and related decision making. Design/methodology/approach – This study explores the concept of fuzzy logic in order to tackle incomplete and inconsistent subjective judgment of the decision makers’ whilst evaluating supply chain’s overall performance. Grey relational analysis has been adopted in the later stage to derive appropriate ranking of alternative companies/enterprises (in the same industry) in view of ongoing SCP extent. Findings – In this work, a perf...
Benchmarking: An International Journal, 2014
Purpose– Lean manufacturing is an operational strategy oriented toward achieving the shortest pos... more Purpose– Lean manufacturing is an operational strategy oriented toward achieving the shortest possible cycle time by eliminating waste. It is derived from the Toyota Production System and its key thrust is to increase the value-added work by eliminating waste and reducing incidental work. In today's competitive global marketplace, the concept of lean manufacturing has gained vital consciousness to all manufacturing sectors, their supply chains, and hence a logical measurement index system is indeed required in implementing leanness in practice. Such leanness estimation can help the enterprises to assess their existing leanness level and can compare different industries who are adapting this lean concept. The paper aims to discuss these issues.Design/methodology/approach– The present work exhibits an efficient fuzzy-based leanness assessment system using generalized interval-valued (IV) trapezoidal fuzzy numbers set. The concept of “degree of similarity” between two IV fuzzy numb...
Journal of Intelligent Manufacturing, 2014
This paper proposes an experimental investigation and optimization of various machining parameter... more This paper proposes an experimental investigation and optimization of various machining parameters for the die-sinking electrical discharge machining (EDM) process using a multi-objective particle swarm (MOPSO) algorithm. A Box-Behnken design of response surface methodology has been adopted to estimate the effect of machining parameters on the responses. The responses used in the analysis are material removal rate, electrode wear ratio, surface roughness and radial overcut. The machining parameters considered in the study are open circuit voltage, discharge current, pulse-on-time, duty factor, flushing pressure and tool material. Fifty four experimental runs are conducted using Inconel 718 super alloy as work piece material and the influence of parameters on each response is analysed. It is observed that tool material, discharge current and pulseon-time have significant effect on machinability characteristics of Inconel 718. Finally, a novel MOPSO algorithm has been proposed for simultaneous optimization of multiple responses. Mutation operator, predominantly used in genetic algorithm, has been introduced in the MOPSO algorithm to avoid premature convergence. The Pareto-optimal solutions obtained through MOPSO have been ranked by the composite scores obtained through maximum deviation theory to avoid subjectiveness and impreciseness in the decision making. The analysis offers useful information for control
International Journal of Productivity and Quality Management, 2014
In any manufacturing system, multi-objective optimisation problem is usually encountered because ... more In any manufacturing system, multi-objective optimisation problem is usually encountered because it is desired to improve multiple criteria of the process/product simultaneously. However, it is really difficult to solve such problems due to the complex process behaviour. The control parameters (process factors) interact in a complicated manner thereby influencing various process outputs. Direct (main effect) as well as interactive effect of process parameters are to be examined carefully to select the most favourable process environment to achieve desired level of quality output. Taguchi optimisation method is very popular in production engineering field; however, the method fails to solve multi-objective optimisation problems. Therefore, to solve a multi-objective optimisation problem, it is customary to convert multiple objectives into a single performance index (single objective function) which can be optimised finally by Taguchi method. In this work, a fuzzy logic approach has been adopted here to optimise the process environment and to produce quality product. By this approach, the imprecision and uncertainty in experimentation as well as data analysis can be handled conveniently. The study highlights a case study of optimising process parameters to satisfy contradicting requirements of multiple bead geometry parameters of submerged arc weld.
Applied Mechanics and Materials, 2014
Thermal Power Plant (TPP) is one of those discoveries that have changed the daily life of everybo... more Thermal Power Plant (TPP) is one of those discoveries that have changed the daily life of everybody and playing vital role in the present real world. The selection of site for thermal power plant, affects the amount of energy generated, power generation cost, economical development, environment and transmission (loss of power). In present work, fuzzy multi-criteria decision making (FMCDM) approach is proposed for site selection of TPP under partial or incomplete information. The proposed approach initially identified the criteria for site selection of TPP. Then the experts are provided linguistic ratings as well as weights to the potential alternatives against the selected criteria. Fuzzy-TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution) is applied to generate aggregate scores selection of best alternative. Finally a case empirical research is adapted to fruitful the proposed approach.
Procedia Engineering, 2014
This paper highlights the parametric appraisal for burr height and circularity in drilling of hol... more This paper highlights the parametric appraisal for burr height and circularity in drilling of hole on AISI-304 stainless steel using Non-dominated sorting genetic algorithm (NSGA). The major problem arises in drilling operation is the formation of burr and taper which seriously affect the quality of holes in practical applications. The present paper investigates the influence of drilling parameters viz., spindle speed, feed rate, and drill bit diameter on burr height and circularity. A total of twenty numbers of experiments were performed based on face centered central composite design (FCCD) of response surface methodology. Generally, the response surface methodology is used for modeling and analyzing manufacturing problems to understand the parametric effect on process responses individually, but it is unable to handle the multi-response problems. To overcome this limitation, proposed NSGA II is used for evaluation of optimal parametric combination in this study. The NSGA II is an improved approach of genetic algorithm (GA) for multi-objective optimization of process responses where non-dominated solutions having high crowding distance are used to provide diversified Pareto-optimal solutions. Analysis of variance shows that spindle speed significantly influence for the circularity of the drilled hole whereas all the parameters like spindle speed, feed rate and drill diameter influence on burr height. The optimal non-dominated set of solutions obtained through the NSGA II gives the manufacturer more flexibility in decision making in manufacturing process.
Sadhana, 2010
The present study highlights a multi-objective optimization problem by applying utility concept c... more The present study highlights a multi-objective optimization problem by applying utility concept coupled with Taguchi method through a case study in CNC end milling of UNS C34000 medium leaded brass. The study aimed at evaluating the best process environment which could simultaneously satisfy multiple requirements of surface quality. In view of the fact, the traditional Taguchi method cannot solve a multi-objective optimization problem; to overcome this limitation, utility theory has been coupled with Taguchi method. Depending on Taguchi's Lower-the-Better (LB) response criteria; individual surface quality characteristics has been transformed into corresponding utility values. Individual utility values have been aggregated finally to compute overall utility degree which serves as representative objective function for optimizing using Taguchi method. Utility theory has been adopted to convert a multi-response optimization problem into a single response optimization problem; in which overall utility degree serves as the representative single objective function for optimization. The study of combined utility theory and Taguchi method for predicting optimal setting. Based on Taguchi's Signal-to-Noise ratio (S/N), analysis has been made on the overall utility degree and optimal process environment has been selected finally which corresponds to highest S/N Ratio. Optimal result has been verified through confirmatory test. The case study indicates application feasibility of the aforesaid methodology proposed for multiresponse optimization and off-line control of multiple surface quality characteristics in CNC end milling.
Measurement, 2013
RENE80 nickel super alloy is widely used in aerospace industry and difficult to machine due to it... more RENE80 nickel super alloy is widely used in aerospace industry and difficult to machine due to its high hardness, high temperature strength and low thermal conductivity and high reactivity with the tools during machining. Hence it can be machined by non-traditional processes like EDM or its variants. In this paper, multi-response optimization of rotary EDM of RENE80 is carried out with copper electrode. ANOVA results indicate that peak current and rotational speed of electrode are significant contributors to various responses. Confirmation experiments showed significant improvements in radial overcut, surface roughness and metal removal rate as 8.73%, 20.82% and 17.93% respectively.
International Journal of Services and Operations Management, 2013
In this paper, grey relational analysis and fuzzy technique of order preference by a similarity t... more In this paper, grey relational analysis and fuzzy technique of order preference by a similarity to ideal solution (fuzzy TOPSIS) methods are proposed for selection of rapid prototyping systems considering both benefit and non-benefit criteria. The criteria may be qualitative or quantitative in nature. The results of grey relational analysis are compared with well-known fuzzy TOPSIS method. The advantage of grey theory over fuzzy theory is that grey theory considers the condition of the fuzziness, i.e., grey theory can deal flexibly with the fuzziness situation. Six RP systems are chosen and compared addressing to various criteria such as dimensional accuracy and surface quality, part cost, build time and material properties. Finally, it has been concluded that selective laser sintering (SLS 2500) is the most appropriate RP system for better dimensional accuracy and surface quality whereas 3-D printing (Z 402) is an appropriate RP system for better build time.
International Journal of Productivity and Quality Management, 2010
In the present reporting, a methodology adapted from multicriteria decision-making (MCDM) has bee... more In the present reporting, a methodology adapted from multicriteria decision-making (MCDM) has been proposed in order to evaluate the overall performance of a teacher. Grey relational analysis has been explored in order to prioritise quality attributes that are expected to ...
International Journal of Process Management and Benchmarking, 2013
In today’s era of globalisation, manufacturing sectors are being forced towards managing environm... more In today’s era of globalisation, manufacturing sectors are being forced towards managing environmental sustainability in account of leverage of numerous serious global warming issues. A multiple index-based green supply chain (GSC) performance appraisement framework has been conceptualised here from the resource literature survey to empirically investigate several sustainability issues related to environmental performance of preferred candidate alternative industries. In this reporting, the subjectivity of the evaluation information has been taken into consideration by deploying a hierarchical fuzzy-based computation module capable of dealing with uncertain environment. Due to inherent ambiguity, vagueness, impreciseness and inconsistency associated with subjective information of the GSC performance indices (metric and measures); the assessment of expert panels acquired for the preferred alternative in linguistic terms pointed out by the adaptation of interval-valued fuzzy number (IVFN). Therefore, a new ...
International Journal of Logistics Systems and Management, 2013
Agility metrics are difficult to define, mainly due to the multidimensionality and vagueness of t... more Agility metrics are difficult to define, mainly due to the multidimensionality and vagueness of the concept of agility. In this paper, a fuzzy logic, knowledge-based framework has been presented for the assessment of an enterprise’s agility; in an Indian perspective. The necessary expertise explored to quantitatively determine and evaluate overall agility degree has been represented via fuzzy expert systems. Apart from estimating overall agility appraisement index; the study has been extended to identify agile barriers (obstacles towards achieving agility). The proposed appraisement module has been implemented in an Indian enterprise as a case study. Data obtained thereof, has been critically analysed to reveal the current scenario of existing agile practices of the said enterprise and to seek for ill-performing areas which need future improvement.
International Journal of Logistics Economics and Globalisation, 2011
In today's business scenario, enterprises have become more concerned towards mass customisation (... more In today's business scenario, enterprises have become more concerned towards mass customisation (MC) providing a wide variety of products that satisfy customers' specific requirements. Enormous product variety invites escalating costs and complexity in manufacturing context. In order to respond to the mass customisation trend, it is felt indeed necessary to develop an agility-based manufacturing system to embrace the traits involved in MC. Agility index of mass customisation and the management and technology dimension associated with the specific system are really helpful to deal with the critical elements of implementing MC. To this end, the present reporting highlights on an MC product manufacturing agility evaluation approach based on the characteristics of MC product manufacturing and the requirement of agile manufacturing, by considering: 1 MC enterprise's organisation management agility evaluation 2 MC products design agility evaluation 3 MC manufacture agility evaluation. Interval-valued fuzzy sets (IVFS) have been adopted in this evaluation model. A fuzzy agility index (FAI) has been computed and compared with predefined agility measurement scale to assess the extent of agility in MC product manufacturing.
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Papers by siba sankar Mahapatra