hamed fazlollahtabar - Profile on Academia.edu (original) (raw)

Papers by hamed fazlollahtabar

Internet of Things-based SCADA system for configuring/reconfiguring an autonomous assembly process

Robotica

Industry 4.0 integrated with robotic and digital fabrication technologies have attracted the atte... more Industry 4.0 integrated with robotic and digital fabrication technologies have attracted the attention of manufacturing researchers. Autonomous assembly with supervisory control and data acquisition (SCADA) systems holds the promise of greater scalability, adaptability, and potentially evolved design possibilities helping to maintain efficiency, process data for smarter decisions, and communicate system issues to help mitigate downtime. This paper concerns with developing an intelligent control system based on SCADA in the Internet of Things (IoT) platform to process configuration and reconfiguration of an autonomous assembly system. The implementation study certifies the effectiveness of the proposed IoT-based SCADA control system in autonomous assembly.

… analysis based comparison of two hybrid multi-criteria decision-making approaches for mobile phone selection: a case study in Iranian telecommunication …

International Journal of …, 2008

... Step 6. Finally, the preference order is ranked ... next step, the questionnaire, depicted in... more ... Step 6. Finally, the preference order is ranked ... next step, the questionnaire, depicted in Table 1, has been designed to elicit and assess information on preferences of the ... 1 The brand of the phone (the marketing vision of brand) 2 Existence of the technical assistance of the brand ...

A Multi Depot Simultaneous Pickup and Delivery Problem with Balanced Allocation of Routes to Drivers

In this paper, a new mathematical model is developed for a multi-depot vehicle routing problem wi... more In this paper, a new mathematical model is developed for a multi-depot vehicle routing problem with simultaneous pickup and delivery. A non-homogenous fleet of vehicles and a number of drivers with different levels of capability are employed to service customers with pickup and delivery demands. The capability of drivers is considered to have a balanced distribution of travels. The objective is to minimize the total cost of routing, penalties for overworking of drivers and fix costs of drivers’ employment. As this problem is proven to be NP-hard, two meta-heuristic approaches based on Imperialist Competitive Algorithm (ICA) and Genetic Algorithm (GA) are employed to solve the generated problems. The parameter tuning is conducted by Taguchi experimental design method. The obtained results show the high performance of the proposed ICA in the quality of the solutions and computational time

Knowledge with Innovation Performance

Knowledge Engineering, 2020

Communications in Statistics - Theory and Methods, 2017

Current design practice is usually to produce a safety system which meets a target level of perfo... more Current design practice is usually to produce a safety system which meets a target level of performance that is deemed acceptable by the regulators. Safety systems are designed to prevent or alleviate the consequences of potentially hazardous events. In many modern industries the failure of such systems can lead to whole system breakdown. In reliability analysis of complex systems involving multiple components, it is assumed that the components have different failure rates with certain probabilities. This leads into extensive computational efforts involved in using the commonly employed generating function (GF) and the recursive algorithm to obtain reliability of systems consisting of a large number of components. Moreover, when the system failure results in fatalities it is desirable for the system to achieve an optimal rather than adequate level of performance given the limitations placed on available resources. This paper concerns with developing a modified branching process joint with generating function to handle reliability

Chapter 4 Cost Parameters and Costing Models in Autonomous Manufacturing

Cost Engineering and Pricing in Autonomous Manufacturing Systems, 2019

In the reverse supply chain the basic concern is to categorize the returned materials in the usab... more In the reverse supply chain the basic concern is to categorize the returned materials in the usable or non-usable ones for performing the required operations to resend them in the supply chain. Companies can obtain more confidence from their consumers to carry out continuous revers logistics removing the defective products. To begin the reverse multi-layer multi-product supply chain and after collecting the returning commodities, we cluster them via k-mean algorithm in Matlab software environment. The results are used to perform a sampling process to deliver the commodities to the related layer for rework and repair operations. The computations show an extensive reduction in the human resource costs for separation of the returning items and increasing the efficiency.

Knowledge Sharing and Learning Capability

Knowledge and Innovation in Networked Environments

Multi-Layer Multi-Product Supply Chain: Strategic Marketing Model

Journal of Advances in Management Sciences & Information Systems, 2015

Today, markets are equipped with IT-based systems to facilitate the flow of information within ma... more Today, markets are equipped with IT-based systems to facilitate the flow of information within markets and to provide useful information for producers and costumers. Therefore, real time decision making is a significant issue of IT environment for obtaining maximum profit in markets. A valuable tool for real time decision making are Decision Support Systems (DSSs). Here, we propose a DSS to identify a set of optimal markets for a producer. The producer aims to determine the markets that provide more profit for him via information systems of markets that analyze all transactions and prepare reports. Due to these reports the producer would decide about markets that provide the maximum profit. The effectiveness of the proposed integrated model is illustrated through numerical example.

A genetic optimization algorithm for nonlinear stochastic programs in an automated manufacturing system

Journal of Intelligent & Fuzzy Systems, 2015

We concern with both time and cost optimization in an automated manufacturing system. In our prop... more We concern with both time and cost optimization in an automated manufacturing system. In our proposed system, material handling is carried out by automated guided vehicles and robots for the manufacturing functions. In this way, defect rates, breakdown times, waiting time, processing time, and certain other parameters are not expected to be deterministic. Therefore, we apply stochastic programming to optimize the production time and material handling cost. The proposed stochastic program is a nonlinear model, for this reason we apply a successive linear programming SLP technique for its optimization. Numerical test results point to the inefficacy of the proposed optimization method for large sized problems. Hence, a genetic algorithm GA is presented to optimize large sized problems.

Yugoslav Journal of Operations Research, 2019

In this paper, we carry out queuing analysis to examine and integrate a quality control (inspecti... more In this paper, we carry out queuing analysis to examine and integrate a quality control (inspection) process into a multi-stage flexible ow shop configured in an M=M=1 queue system. Our main concern is to improve the performance of multi-stage exible ow shop production. Besides, this work aims to help managers in improving their effeciency and effectiveness, and in selecting a joint inspection, being the most suitable policy for minimizing inspection and queueing related costs. We adopt an analytical approach based on real-life data from a Kach company that produces disposable appliances. Queuing analysis reported in this work provides a basis for estimating and analyzing production systems by measures such as utilization, the percentage of the idle workstation, number of batches in the system, number of batches in the queue, expected time spent in the queue, and expected time spent in the system. The results indicate the performance of the company in relation to inspection and expe...

Assembly Automation, 2019

Purpose In real manufacturing systems, schedules are often disrupted with uncertainty factors suc... more 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 (ANO...

Comparative Simulation Study for Configuring Turning Point in Multiple Robot Path Planning: Robust Data Envelopment Analysis

Robotica, 2019

SUMMARYThis paper concerns with comparing simulation studies for a newly developed concept of tur... more SUMMARYThis paper concerns with comparing simulation studies for a newly developed concept of turning point to be used in multiple robot path planning. Different critical factors and design parameters are collected and statistical analyses are performed. After configuring different simulation scenarios, the efficient one is evaluated using a robust data envelopment analysis (RDEA). Due to uncertain aspects of various simulations scenarios, robust version of data envelopment analysis is proposed. Here, major criteria in robot path planning are deadlock and conflict avoidance, throughput, mean flow time, and effective total distance travelled. To determine the effective experiment for the proposed simulation model, RDEA is used. A comparative study with respect to different experiments having various simulation setting is developed. The results for a real robotic manufacturing cell system show effectiveness of the proposed process. Also, the efficient simulation software is determined...

Operational Research in Engineering Sciences: Theory and Applications, 2019

Reverse supply chain is a process dealing with the backward flows of used/damaged products or mat... more Reverse supply chain is a process dealing with the backward flows of used/damaged products or materials. Reverse supply chain includes activities such as collection, inspection, reprocess, disposal and redistribution. A well-organized reverse supply chain can provide important advantages such as economic and environmental ones. In this study, we propose a configuration in which quality assurance is a substantial operation to be fulfilled in the reverse chain so that to minimize the total costs of the reverse supply chain. A mathematical model is formulated for product return in reverse supply chain considering quality assurance. We consider a multilayer, multi-product for the model. Control charts with exponentially weighted moving average (EWMA) statistics (mean and variance) are used to jointly monitor the mean and variance of a process. An EWMA cost minimization model is presented to design the joint control scheme based on performance criteria. The main objective of the paper is minimizing the total costs of reverse supply chain with respect to inspection.

Quality and Reliability Engineering International, 2017

Availability of a system is a crucial factor for planning and optimization. The concept is more c... more Availability of a system is a crucial factor for planning and optimization. The concept is more challenging for modern systems such as robots and autonomous systems consisting of a complex configuration of components. In this paper, a reliability evaluation framework is developed for a system of binary state autonomous robots in an automated manufacturing environment. In this framework, the concepts in functional block diagram, table of truth, and sum of state are employed simultaneously to develop a binary state reliability model. Due to inefficacy of the method for larger number of components involved in complex systems, an extension of the Bernoulli trials is proposed. In an implementation study, the effectiveness and computational efficiency of the proposed method are illustrated. In addition, an analysis on the failure rate using the maximum likelihood estimation and confidence interval is reported.

Integration of fault tree analysis, reliability block diagram and hazard decision tree for industrial robot reliability evaluation

Industrial Robot: An International Journal, 2017

Purpose This paper aims to conduct a comprehensive fault tree analysis (FTA) on the critical comp... more Purpose This paper aims to conduct a comprehensive fault tree analysis (FTA) on the critical components of industrial robots. This analysis is integrated with the reliability block diagram (RBD) approach to investigate the robot system reliability. Design/methodology/approach For practical implementation, a particular autonomous guided vehicle (AGV) system was first modeled. Then, FTA was adopted to model the causes of failures, enabling the probability of success to be determined. In addition, RBD was used to simplify the complex system of the AGV for reliability evaluation purpose. Findings Hazard decision tree (HDT) was configured to compute the hazards of each component and the whole AGV robot system. Through this research, a promising technical approach was established, allowing decision-makers to identify the critical components of AGVs along with their crucial hazard phases at the design stage. Originality/value As complex systems have become global and essential in today’s s...

Production & Manufacturing Research, 2016

Fazlollahtabar (2016) Genetic and artificial bee colony algorithms for scheduling of multi-skille... more Fazlollahtabar (2016) Genetic and artificial bee colony algorithms for scheduling of multi-skilled manpower in combined manpower-vehicle routing problem,

Parallel autonomous guided vehicle assembly line for a semi-continuous manufacturing system

Assembly Automation, 2016

Purpose This paper aims to propose a parallel automated assembly line system to produce multiple ... more Purpose This paper aims to propose a parallel automated assembly line system to produce multiple products in a semi-continuous system. Design/methodology/approach The control system developed in this research consists of a manufacturing system for two-level hierarchical dynamic decisions of autonomous/automated/automatic-guided vehicles (AGVs) dispatching/next station selection and machining schedules and a station control scheme for operational control of machines and components. In this proposed problem, the assignment of multiple AGVs to different assembly lines and the semi-continuous stations is a critical objective. AGVs and station scheduling decisions are made at the assembly line level. On the other hand, component and machining resource scheduling are made at the station level. Findings The proposed scheduler first decomposes the dynamic scheduling problems into a static AGV and machine assignment during each short-term rolling window. It optimizes weighted completion time...