The simulation models are used as for decision support and learning in enterprises and in schools... more The simulation models are used as for decision support and learning in enterprises and in schools. Tree cases of successful applications demonstrate usefulness of weak anticipative information. Job shop scheduling production with makespan criterion presents a real case customized flexible furniture production optimization. The genetic algorithm for job shop scheduling optimization is presented. Simulation based inventory control for products with stochastic lead time and demand describes inventory optimization for products with ...
This paper presents a method of warehouse simulation model implementation using concepts of virtu... more This paper presents a method of warehouse simulation model implementation using concepts of virtual reality (VR). The basic idea is to compare the “Real Process” controlled by operator with his/her heuristics with the “Virtual Process” represented by a simulation model, controlled by the optimization algorithm. The optimization algorithm is based on a SD model of the warehouse and decision support module. The SD warehouse model represents the abstraction of “Virtual Process” and is considered to be a model of a model. ...
This paper presents a method of warehouse simulation model implementation using concepts of virtu... more This paper presents a method of warehouse simulation model implementation using concepts of virtual reality (VR). The basic idea is to compare the “Real Process” controlled by operator with his/her heuristics with the “Virtual Process” represented by a simulation model, controlled by the optimization algorithm. The optimization algorithm is based on a SD model of the warehouse and decision support module. The SD warehouse model represents the abstraction of “Virtual Process” and is considered to be a model of a model. ...
This paper describes experiences in teaching of a Modelling and simulation course at the Faculty ... more This paper describes experiences in teaching of a Modelling and simulation course at the Faculty of Organizational Sciences. The course consists of continuous simulation based on System Dynamics (SD) and discrete event simulation (DES). When enrolling the course the students have already taken courses of Mathematics, Statistics, Systems Theory, as well as Organization and Economics. The final grade of the course is derived from the student's project and written exam. Attendance at lectures is not obligatory; only the practical exercises are. In this paper, we will discuss the methods of teaching SD by using the classical approach of teaching, and by the application of a business simulator. Therefore, we have developed the simulation model in order to explicate the usefulness of the simulation in solving management problems. Students took part in the experiment with the simulation model; the obtained results were analyzed afterward in the students' projects. After the experiment, students had to complete a questionnaire on their opinion of the course. The results show that students taking the course of Modelling and Simulation thought that application of the simulation model contribute to a better problem understanding, faster problem solving and greater confidence of participants.
Abstract Interaction of discrete dynamics Kaldor's anticipative cobweb agents is ana... more Abstract Interaction of discrete dynamics Kaldor's anticipative cobweb agents is analyzed. Interaction rule between agents is determined by the floor-roof principle. As the main property the synchronization emerges. Emergent synchronization rule was determined by application of z-transform. Nonlinear expansion of anticipative model provided emergent attractor response. Determination of stability is explored by the regions where Lyapunov exponents are negative.
The paper addresses an important part of enterprise activity, which is the warranty claims contro... more The paper addresses an important part of enterprise activity, which is the warranty claims control and prediction. Warranty claims have a significant impact on the financial aspect of the company, because of the funds that need to be reserved for repair of the defected products within the warranty period. The failure process is considered as a combination of market absorption and failure process. Prediction and determination of terminal call rate (TCR) is important for monitoring of the production system efficiency. Several models to predict TCR have been analyzed, such as Weibull model and the Markov Modulated Fluid model (MMFM). The models were validated against two types of data: a) from sales to failure, and b) from production to failure. The results show that MMFM model provides promising prediction results.
Scheduling and timetable creation represents a big problem for time table creators. We developed ... more Scheduling and timetable creation represents a big problem for time table creators. We developed software for creating (calculating) time tables, that uses evolutionary algorithm (EA). We compared our software – Algit Timetable (slo. – iUrnik) with the most commonly used software Slovenian schools use nowadays. We evaluated their current time tables and under the same conditions and demands, we compared it with the timetable our program had created.
This chapter presents a real case study of inventory control optimization in the automobile parts... more This chapter presents a real case study of inventory control optimization in the automobile parts manufacturing firm that is facing a challenging task of predicting the demand, especially if a modern turbulent business environment is considered, where customer’s needs are changing frequently. Furthermore, such an environment also impacts the delivery process, where lead times show some degree of discrepancy. The inventory control simulation model, which was built according to the System Dynamics methodology, is presented. Several inventory control algorithms, such as Least-unit cost, Part period balancing, Silver-Meal algorithm, and a fuzzy adaptive inventory control algorithm were tested on real data. The inventory control model, which is combined with the inventory control algorithms and fuzzy strategy assessor, is a part of a proposed decision support system to help order managers to solve the problem of when to place an order and how many items to order.
This paper gives an analysis of cruise ship arrivals and a proposal for ship servicing with impro... more This paper gives an analysis of cruise ship arrivals and a proposal for ship servicing with improved tendering service at anchorages. The increased trends in cruise ship port calling during the last few years represent a good foundation for evaluating the performance of the port and to predict the future port throughput. The main goal of this paper is to show one of the available solutions for passenger embarking/disembarking in the cruise port, via tendering service. The reasons for employing tendering service are presented, because certain ships cannot be docked in port because of the draft and other limitations. The forecasts on future traffic intensity and a number of ships that need tendering services with linear regression are given. Finally, options to cope with increased traffic intensity are discussed.
This paper describes the problem of human resource management which can appear in many organiza- ... more This paper describes the problem of human resource management which can appear in many organiza- tions during restructuration periods. The problem is simulated by a dynamic model, similar to a supply chain model with several ranks. The problem of finding the optimal combination of transition coefficients, including the fluctuation coefficients, is transformed into an optimization problem. To solve this prob- lem, a self-configuring genetic algorithm is applied with several constraint handling methods. Additional constraints are defined in order to avoid undesirable oscillations in the system. The results show that this problem can be efficiently solved by the presented methods.
The paper tackles the issue of restructuring strictly hierarchical organizational structure. Syst... more The paper tackles the issue of restructuring strictly hierarchical organizational structure. System that allows the determination of strategies for achieving the desired states is developed using the programming language JavaScript/ECMAScript. It consists of a simulation model based on system dynamics, genetic algorithms, finite state automata and graphical user interface. Developed solution can be used via the internet on mobile devices.
The simulation models are used as for decision support and learning in enterprises and in schools... more The simulation models are used as for decision support and learning in enterprises and in schools. Tree cases of successful applications demonstrate usefulness of weak anticipative information. Job shop scheduling production with makespan criterion presents a real case customized flexible furniture production optimization. The genetic algorithm for job shop scheduling optimization is presented. Simulation based inventory control for products with stochastic lead time and demand describes inventory optimization for products with ...
This paper presents a method of warehouse simulation model implementation using concepts of virtu... more This paper presents a method of warehouse simulation model implementation using concepts of virtual reality (VR). The basic idea is to compare the “Real Process” controlled by operator with his/her heuristics with the “Virtual Process” represented by a simulation model, controlled by the optimization algorithm. The optimization algorithm is based on a SD model of the warehouse and decision support module. The SD warehouse model represents the abstraction of “Virtual Process” and is considered to be a model of a model. ...
This paper presents a method of warehouse simulation model implementation using concepts of virtu... more This paper presents a method of warehouse simulation model implementation using concepts of virtual reality (VR). The basic idea is to compare the “Real Process” controlled by operator with his/her heuristics with the “Virtual Process” represented by a simulation model, controlled by the optimization algorithm. The optimization algorithm is based on a SD model of the warehouse and decision support module. The SD warehouse model represents the abstraction of “Virtual Process” and is considered to be a model of a model. ...
This paper describes experiences in teaching of a Modelling and simulation course at the Faculty ... more This paper describes experiences in teaching of a Modelling and simulation course at the Faculty of Organizational Sciences. The course consists of continuous simulation based on System Dynamics (SD) and discrete event simulation (DES). When enrolling the course the students have already taken courses of Mathematics, Statistics, Systems Theory, as well as Organization and Economics. The final grade of the course is derived from the student's project and written exam. Attendance at lectures is not obligatory; only the practical exercises are. In this paper, we will discuss the methods of teaching SD by using the classical approach of teaching, and by the application of a business simulator. Therefore, we have developed the simulation model in order to explicate the usefulness of the simulation in solving management problems. Students took part in the experiment with the simulation model; the obtained results were analyzed afterward in the students' projects. After the experiment, students had to complete a questionnaire on their opinion of the course. The results show that students taking the course of Modelling and Simulation thought that application of the simulation model contribute to a better problem understanding, faster problem solving and greater confidence of participants.
Abstract Interaction of discrete dynamics Kaldor's anticipative cobweb agents is ana... more Abstract Interaction of discrete dynamics Kaldor's anticipative cobweb agents is analyzed. Interaction rule between agents is determined by the floor-roof principle. As the main property the synchronization emerges. Emergent synchronization rule was determined by application of z-transform. Nonlinear expansion of anticipative model provided emergent attractor response. Determination of stability is explored by the regions where Lyapunov exponents are negative.
The paper addresses an important part of enterprise activity, which is the warranty claims contro... more The paper addresses an important part of enterprise activity, which is the warranty claims control and prediction. Warranty claims have a significant impact on the financial aspect of the company, because of the funds that need to be reserved for repair of the defected products within the warranty period. The failure process is considered as a combination of market absorption and failure process. Prediction and determination of terminal call rate (TCR) is important for monitoring of the production system efficiency. Several models to predict TCR have been analyzed, such as Weibull model and the Markov Modulated Fluid model (MMFM). The models were validated against two types of data: a) from sales to failure, and b) from production to failure. The results show that MMFM model provides promising prediction results.
Scheduling and timetable creation represents a big problem for time table creators. We developed ... more Scheduling and timetable creation represents a big problem for time table creators. We developed software for creating (calculating) time tables, that uses evolutionary algorithm (EA). We compared our software – Algit Timetable (slo. – iUrnik) with the most commonly used software Slovenian schools use nowadays. We evaluated their current time tables and under the same conditions and demands, we compared it with the timetable our program had created.
This chapter presents a real case study of inventory control optimization in the automobile parts... more This chapter presents a real case study of inventory control optimization in the automobile parts manufacturing firm that is facing a challenging task of predicting the demand, especially if a modern turbulent business environment is considered, where customer’s needs are changing frequently. Furthermore, such an environment also impacts the delivery process, where lead times show some degree of discrepancy. The inventory control simulation model, which was built according to the System Dynamics methodology, is presented. Several inventory control algorithms, such as Least-unit cost, Part period balancing, Silver-Meal algorithm, and a fuzzy adaptive inventory control algorithm were tested on real data. The inventory control model, which is combined with the inventory control algorithms and fuzzy strategy assessor, is a part of a proposed decision support system to help order managers to solve the problem of when to place an order and how many items to order.
This paper gives an analysis of cruise ship arrivals and a proposal for ship servicing with impro... more This paper gives an analysis of cruise ship arrivals and a proposal for ship servicing with improved tendering service at anchorages. The increased trends in cruise ship port calling during the last few years represent a good foundation for evaluating the performance of the port and to predict the future port throughput. The main goal of this paper is to show one of the available solutions for passenger embarking/disembarking in the cruise port, via tendering service. The reasons for employing tendering service are presented, because certain ships cannot be docked in port because of the draft and other limitations. The forecasts on future traffic intensity and a number of ships that need tendering services with linear regression are given. Finally, options to cope with increased traffic intensity are discussed.
This paper describes the problem of human resource management which can appear in many organiza- ... more This paper describes the problem of human resource management which can appear in many organiza- tions during restructuration periods. The problem is simulated by a dynamic model, similar to a supply chain model with several ranks. The problem of finding the optimal combination of transition coefficients, including the fluctuation coefficients, is transformed into an optimization problem. To solve this prob- lem, a self-configuring genetic algorithm is applied with several constraint handling methods. Additional constraints are defined in order to avoid undesirable oscillations in the system. The results show that this problem can be efficiently solved by the presented methods.
The paper tackles the issue of restructuring strictly hierarchical organizational structure. Syst... more The paper tackles the issue of restructuring strictly hierarchical organizational structure. System that allows the determination of strategies for achieving the desired states is developed using the programming language JavaScript/ECMAScript. It consists of a simulation model based on system dynamics, genetic algorithms, finite state automata and graphical user interface. Developed solution can be used via the internet on mobile devices.
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