Mehdi Yazdani
Abstract
This paper deals with the problem of two-stage assembly flow shop scheduling with considering sequence-independent setup times .The objective is to minimize totalcompletion times of all orders. In this problem, there are several orders for one type of product. Each ordered product is formed of several ...
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This paper deals with the problem of two-stage assembly flow shop scheduling with considering sequence-independent setup times .The objective is to minimize totalcompletion times of all orders. In this problem, there are several orders for one type of product. Each ordered product is formed of several different parts. At first, the parts are manufactured in a flow shop stage with some different machines and then they are assembled into a final product on a single machine. This paper presents three meta-heuristic algorithms, namely Parallel Variable Neighborhood Search (PVN) Artificial Immune Algorithm (AIA) and Simulated Annealing (SA), for solving under studied problem. The Taguchi experimental design method as an optimization technique is employed to tune different parameters and operators of presented algorithms. Also, Numerical experiments are used to evaluate the performance of the proposed algorithms. The results show that the PVNS algorithm performs better than the other algorithms
Abstract
. The control and planning of operating rooms have became more and more important for hospital managers. Nowadays, the operating rooms, as key resources, often lead to a great time waste. So, appropriate scheduling of operations in order to increase the efficiency of the operating rooms, are significant ...
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. The control and planning of operating rooms have became more and more important for hospital managers. Nowadays, the operating rooms, as key resources, often lead to a great time waste. So, appropriate scheduling of operations in order to increase the efficiency of the operating rooms, are significant research topics in medical care. In this study, a new linear programming model has been developed for the assignment of patients to the operating rooms. Since the duration of surgical procedure is a stochastic parameter, in this paper a two-stage stochastic programming model has been presented in addition the deterministic model. These presented modelssimultaneously investigate the scheduling of surgeries and allocating them to the surgery rooms. The aim of this study is to minimize the cost of assigning patients to unspecialized rooms and reduce the cost of doctors’ idle time per working shifts by taking into account the constraints. The suggested models were applied for the surgery department of Ghaem hospital of Mashhad and solved by ILOG CPLEX 12.6.1 Microsoft Visual Studio environment. The results show that the deterministic proposed model increases the average efficiency of hospital to 38.275% and the stochastic model increases the average efficiency to 85.32%.
Seyed Mohammad Taghi Fatemi Ghomi; Ehsan Arabzadeh; Behrooz Karimi
Abstract
Home health care services have a key importance in modern societies. Most organizations working in this area in Iran use the traditional procedure to plan and manage medical staff and determine the arrangement of visiting patients. This procedure often increases costs and reduces the satisfaction of ...
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Home health care services have a key importance in modern societies. Most organizations working in this area in Iran use the traditional procedure to plan and manage medical staff and determine the arrangement of visiting patients. This procedure often increases costs and reduces the satisfaction of patients. In this paper, a multi-period routing and scheduling model is proposed in order to visit patients and provide them medical services. Considering both dependency and independence of a patient's visits with each other, assuming the model as multi-depot as well as multi period are some innovations of this study. The main purpose of the proposed model is to reduce total costs of home health care organization. Model has been solved in small scale by GAMS software. To solve the model in large scale, developed Variable neighborhood search is proposed and compared with simulated annealing algorithm and ant colony system. Results show that costs are decreased and the proposed algorithm has better performance
Reza Alikhani; Mahmoud Saremi
Abstract
The scheduling of preventive maintenance and replacement is one of the crucial issues in the literature of system reliability and maintenance engineering. The importance of this issue is more evident in series system in which by stopping a component the whole system will stop. However, the quest of the ...
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The scheduling of preventive maintenance and replacement is one of the crucial issues in the literature of system reliability and maintenance engineering. The importance of this issue is more evident in series system in which by stopping a component the whole system will stop. However, the quest of the efficient periodicity maintenance for all of component of a system which has antagonistic objectives is not a trivial task. The aim of this paper is to presenting scheduling model of preventive maintenance and replacement for series system by variable and not predetertmined periods and also by applying inflation in the model. The model is designed based on fuzzy multi-objective and integer non-linear programming. Also the proposed model is solved for a case study with numerical example and furthermore, analysis of various senarios, the effects of inflation on the model will be considered. The results show that applying inflation in the model changes not only scheduling for replacement and maintenance, but also affects the effective age of components
Darush Mohamadi Zanjirani; Majid Esmailian; Saeedeh Jokar
Abstract
Process planning involves determining the most suitable and efficient manufacturing (assembly) processes and their sequence in order to produce a product (part). These processes should be compatible with required attributes in product design documentation. Process planning and scheduling optimization ...
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Process planning involves determining the most suitable and efficient manufacturing (assembly) processes and their sequence in order to produce a product (part). These processes should be compatible with required attributes in product design documentation. Process planning and scheduling optimization is done with Considering qualitative parameters which are affective on job shop and flexible system. Fuzzy Inference System and Meta-heuristic algorithms with multiple objective and goal functions are used to solving problem. Objective functions include minimization of cost and time of processing parts and maximizing the utility of the process design. based on the illustrated numerical example simulated annealing algorithm has better efficiency than imperialist competitive algorithm, particle swarm, bee colony.
Mehdi Yazdani; Mostafa Zandieh; Reza Tavakkoli-Moghaddam
Volume 12, Issue 33 , July 2015, , Pages 43-74
Abstract
In this paper, the dual-resource constrained flexible job-shop scheduling problem (DRCFJSP) with objective of minimizing the makespan is investigated. Under studied problem is NP-hard and mainly includes three sub-problems. The first one is to assign each operation to a machine out ...
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In this paper, the dual-resource constrained flexible job-shop scheduling problem (DRCFJSP) with objective of minimizing the makespan is investigated. Under studied problem is NP-hard and mainly includes three sub-problems. The first one is to assign each operation to a machine out of a set of capable machines, the second one is to determine a worker among a set of skilled workers for processing each operation on the selected machine and the third one deals with sequencing the assigned operations on the machines considering workers in order to optimize the performance measure. In this paper, we provide a mathematical model for this problem and then propose a hybrid meta-heuristic algorithm for solving the problem. The proposed hybrid algorithm uses variable neighborhood search and simulated annealing algorithms to search in the solution space. Computational study with randomly generated test problems is performed to evaluate the performance of the proposed algorithm. The results show the proposed algorithms are effective approaches for solving the DRCFJSP.
mohammad rahim ramazanian; mohammad hasan gholizadeh; shiva shaban
Volume 11, Issue 29 , July 2013, , Pages 41-59
Abstract
In this paper, based on the background of cost-oriented assembly line balancing problems, a novel mathematical model for scheduling and balancing the assembly line is offered that with the combination of task sequence-dependent setup time, parallel stations and resource constraint, minimizes ...
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In this paper, based on the background of cost-oriented assembly line balancing problems, a novel mathematical model for scheduling and balancing the assembly line is offered that with the combination of task sequence-dependent setup time, parallel stations and resource constraint, minimizes the operational and investment costs of assembly system.
Due to the complexity of the problem, the equations have been proposed to reduce the number of variables of the model, and to achieve the optimal solution in reasonable time using exact algorithms. To clarify and explain the features of the model a numerical example have been used. Also the solutions obtained from model in several examples, have been analyzed using different indexes, and results indicative of appropriate performance of the model
