• International Journal of Naval Architecture and Ocean Engineering
• /
• v.12 no.1
• /
• pp.20-37
• /
• 2020

In this paper, we propose a simulation method based on backward simulation and process-oriented simulation to take into account the characteristics of shipbuilding production, which is an order-based industry with a job shop production environment. The shipyard production planning process was investigated to analyze the detailed process, variables and constraints of mid-term production planning. Backward and process-centric simulation methods were applied to the mid-term production planning process and an improved planning process, which considers the shipbuilding characteristics, was proposed. Based on the problem defined by applying backward process-centric simulation, a system which can conduct Discrete Event Simulation (DES) was developed. The developed mid-term planning system can be linked with the existing shipyard Advanced Planning System (APS). Verification of the system was performed with the actual shipyard mid-term production data for the four ships corresponding to a one-year period.

• Journal of Korean Society for Quality Management
• /
• v.44 no.3
• /
• pp.541-552
• /
• 2016

Purpose: In this study, we propose that how to approach a effective system engineering and optimize system engineering management process for the mass production weapon system parts localization development process and success in DTaQ. Methods: To approach a effective system engineering for the mass production weapon system parts localization, we analyze a weapon system acquisition process and system engineering process of Republic of Korea and DTaQ parts localization business regulations in advance. after results of analysis of them, we implement a optimized parts localization development system engineering based on ISO/IEC/IEEE 15288. Results: In order to apply International Standard ISO/IEC/IEEE 15288 to the mass production weapon system parts localization development process, we compare the mass production weapon system parts localization acquisition environment with ISO/IEC/IEEE 15288 and analyze them. therefore, It is possible to implement a part of concept stage and development stage of ISO/IEC/IEEE total life cycle stage for the mass production weapon system parts localization development process. To achieve the technical review milestones of DTaQ parts localization business regulations in the selected stages of ISO/IEC/IEEE, the development and management agency perform 2 high rank process and 19 low rank process specified in ISO/IEC/IEEE. Conclusion: When the development and management agency perform the mass production weapon system parts localization development using the proposed system engineering approach, they should easily meet milestone through the clarified requirement and simplified System Engineering output documents in limited development period.

• Ocean Systems Engineering
• /
• v.9 no.3
• /
• pp.329-347
• /
• 2019

The shipbuilding industry is characterized by order production, and various processes are performed simultaneously in the construction of ships. Therefore, effective management of the production process and productivity improvement form important key factors in the industry. For decades, researchers and process managers have attempted to improve processes by using business process analysis (BPA). However, conventional BPA is time-consuming, expensive, and mainly based on subjective results generated by employees, which may not always correspond to the actual conditions. This paper proposes a method to improve the production process of offshore plant modules by analysing the process mining data obtained from the shipbuilding industry. Process mining uses information accumulated from the system-provided event logs to generate a process model and determine the values hidden within the process. The discovered process is visualized as a process model. Subsequently, alternatives are proposed by brainstorming problems (such as bottlenecks or idle time) in the process. The results of this study can aid in productivity improvement (idle time or bottleneck reduction in the production process) in conjunction with a six-sigma technique or ERP system. In future, it is necessary to study the standardization of the module production processes and development of the process monitoring system.

• Journal of the Korea Safety Management & Science
• /
• v.9 no.6
• /
• pp.163-169
• /
• 2007

This study deals with the improvement of production process on a flow production system with the consideration of six sigma. We analyze the production process and survey the important factors of improvement of productivity. Using a six sigma, we find strategic point and suggest a reformation of production process. We applied a simulation technique to simulate the production line proposed by the result of the Six sigma. With the result of the simulation, this study analyzes the propriety of production line and proposes the alternatives of new production process.

• Journal of the Korea Safety Management & Science
• /
• v.5 no.4
• /
• pp.169-185
• /
• 2003

Recently many researchers contributed to the understanding of Quality Control System, but the use of economics in the design of quality assurance system is limited in treatment of the relationship between the average incoming quality level (or average process quality level) of the incoming lot and the average outgoing quality level of this lot. In this study, a traditional concept of sampling inspection plan for the quality assurance system is extended to a consideration of economic aspects in total production system by representing and analyzing the effects between proceeding and succeeding production process including inspection process. This approach recognizes that the decision at each manufacturing process (or assembly process), is to be determined not only by the cost and the average outgoing quality level of that process, but also by the input parameters of the cost and the incoming quality to the succeeding process. By analyzing the effects of the average incoming and outgoing quality, manufacturing or assembly process quality level and sampling inspection plan on the production system, mathematical models and solution technique to minimize the total production cost for a general product manufacturing system with specified average outgoing quality limit are suggested.

• IE interfaces
• /
• v.21 no.4
• /
• pp.418-434
• /
• 2008

This paper studied issues in decision making on the production control policy of a cathode plate manufacturing process in zinc refining plant. The present production system has a long lead time from raw materials (aluminum plate) to products (cathode plate) due to many WIP inventories. Because WIP inventories are stocked at each process and moved from one place to another frequently, they are the main cause of inefficiency in the process. In this paper, to solve this problem, several production control policies have been identified and studied. Several simulation models are used to compare the performances of these production control policies. The output lead time and WIP (Work In Process) of real production system are compared with those of simulation models. PUSH, CONWIP, DBR, KANBAN and CONWIP-DBR models have been used to simulate and review the optimized production control policy that achieves the target output quantities with decreased lead time and WIP. The simulation results of each production control policy show that CONWIP and CONWIP-DBR models are the good production control policy under the present production system. Especially in present production system, CONWIP with one parameter is easier control policy than CONWIP-DBR with two parameters. Therefore CONWIP has been selected as the best optimum production control policy. With CONWIP, lead time has been reduced by 97% (from 6,653 to 187 minute) and WIP has been reduced from 1,488 to 53, compared to the present system.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.42 no.1
• /
• pp.55-63
• /
• 2019

This paper develops an algorithm to determine the batch size of the batch process in real time for improving production and efficient control of production system with multiple processes and batch processes. It is so important to find the batch size of the batch process, because the variability arising from the batch process in the production system affects the capacity of the production. Specifically, batch size could change system efficiency such as throughput, WIP (Work In Process) in production system, batch formation time and so on. In order to improve the system variability and productivity, real time batch size determined by considering the preparation time and batch formation time according to the number of operation of the batch process. The purpose of the study is to control the WIP by applying CONWIP production system method in the production line and implements an algorithm for a real time batch size decision in a batch process that requires long work preparation time and affects system efficiency. In order to verify the efficiency of the developed algorithm that determine the batch size in a real time, an existed production system with fixed the batch size will be implemented first and determines that batch size in real time considering WIP in queue and average lead time in the current system. To comparing the efficiency of a system with a fixed batch size and a system that determines a batch size in real time, the results are analyzed using three evaluation indexes of lead time, throughput, and average WIP of the queue.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.8 no.3
• /
• pp.54-61
• /
• 2009

General manufacturing process of the manufacturing time and manufacturing process problems have a problem. In the past, in the manufacturing process the data by hand has been. Therefore, the production performance management information, and materials input, output information, equipment information of the failure of the management problems emerged. Through this research, improvements in real-time production information to collect distribution and overall productivity will increase the efficiency of the system. the production process to improve the quality of management, efficient production methods are presented. is a stable quality control. POP system The new building should be. This is the executive or administrative decisions support. It increases productivity, efficiency, and reduce production costs, increase product reliability. This will increase the company's reputation. This increases the competitiveness of enterprises. POP system toward the future with the new destroyer to prepare for our company. Collectively POP system build this research improves the reliability of the product. Improves the quality of customer service. The expansion of product sales is. increase the competitiveness of enterprises. companies should prepare for the future of the business.

• Journal of the Korea Society for Simulation
• /
• v.11 no.4
• /
• pp.69-80
• /
• 2002

This study deals with the productivity improvement on a flow production system with the consideration of line-balancing. In a flow production system, similar product models are produced on a same assembly line, the predefined process order and the limitation of total worker number. The system can be increased the work-in -process(WIP) inventory and the worker's idle time. In this study, the worker assignment model is developed to assign evenly workload of process to each product model in such a manner that each process has the different number of worker. This worker assignment model is the mathematical model that determines worker number in each process such that the idle time of processes is reduced and the utilization of worker is improved. We use a simulation technique to simulate the production line proposed by the mathematical model and apply real production line. With the result of simulation, this study analyzes the propriety of production line and proposes the alternatives of new production line

• The Journal of Information Systems
• /
• v.27 no.3
• /
• pp.25-42
• /
• 2018

Purpose The purpose of this study focused on adopting production systems in cognitive psychology to improve the extraction process of persuasive design characteristics for healthcare-related mobile applications. Design/Methodology/Approach A research approach with four stages was developed. We developed and updated the evaluation guideline for persuasive design characteristics (PDC). We tried to summarize and analyze each of 28 PDC and prepared related production rules. Verification process for both guideline approach and production system approach were performed. Top one hundred apps from both medical category and health and Fitness category were selected and evaluated by two approaches. By comparing the results of the two approaches, we tried to explain the improvement and reliability of introducing the production system in the PDC extraction process. Findings Based on the updated guideline for healthcare-related mobile applications, a production system in cognitive psychology was developed. By comparing the PDC extraction results by two approaches, production system showed a better improvement for evaluation precision and efficiency for decision-making process. The findings of this study can be used for researchers and app developers to apply production system to analyze, evaluate, and develop better healthcare-related apps with persuasion.