• Korean Journal of Computational Design and Engineering
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• v.13 no.3
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• pp.235-242
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• 2008

This paper proposes a method for improving the process plan quality by use of dimensional tolerances. Dimensioning and tolerancing plays a key role in manufacturing process plan because the final part must ensure conformance with the dimensions and tolerances in its drawing. As a first step for the improvement of process plan quality, two resultant tolerances in design and process plan should be compared each other, and so a tolerance chart is used for acquisition and comparison of the two tolerances. In addition to two kinds of design and manufacturing tolerances, operational sequences or paths for the resultant dimension and tolerance are additionally recognized for measuring the quality of process plan quantitatively. Rooted tree is applied to find the related paths for the manufacturing resultant tolerances. A quality coefficient is defined by the components of two tolerances and their relations, the paths related to manufacturing resultant tolerances and the difficulty of an operation. In order to improve the quality of manufacturing process plan, the paths that two kinds of tolerances are the same or different in the rooted tree are recognized respectively and a method for tolerance rearrangement is developed. A procedure for improving the quality is suggested by combining the coefficient and the tolerance rearrangement method. A case study is applied to illustrate the efficiency of improvement method.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.1124-1128
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• 2005

In this paper, a plan-coordination architecture is proposed for multi-agent control in the fractal manufacturing system (FrMS). A fractal in FrMS is a set of distributed agents whose goal can be achieved through cooperation, coordination, and negotiation with other agents. Since each agent in the FrMS generates, achieves, and modifies its own plan fragments autonomously during the coordination process with other agents, it is necessary to develop a systematic methodology for the achievement of global plan in the manufacturing system. The heterarchical structure of the FrMS provides a compromised plan-coordination approach, it compromise a centralized plan-generation/execution (which mainly focuses on the maximization of throughput) with a distributed one (which focuses on the autonomy of each module and flexibility of the whole system). Plan-coordinators in lower level fractal independently generate plan fragments according to the global plan of higher level fractal, and plan-coordinators in higher level fractal mediate/coordinate the plan fragments to enhance the global performance of the system. This paper assumes that generation method of the plan fragments and the negotiation policy of the fractal is achieved by a simple process, and we mainly focuses on the information exchanging and distributed decision making process to coordinate the combinations of plan fragments within a limited exchange of information.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.17-27
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• 2014

The number of manufacturing companies that demand the ability to assess sustainability in their manufacturing system is rapidly increasing. However, there are still difficulties in assessing their sustainability in manufacturing for decision-making since it is not easy to determine a single index of sustainability in an operational way. To address these difficulties, this paper proposes an operational guidance and system to assess sustainability of production plan as a single index. The IDEF0 model was defined to explain processes and their input, output, control, and mechanism for sustainability assessment. A prototype system was developed based on the concepts presented in the IDEF0 model, and applied to a case study. To conclude, the prototype system proposed in this paper can help manufacturing companies assess sustainability of their production plans and make a decision using a single value resulted from that assessment.

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.3
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• pp.69-78
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• 2001

This paper presents a process and operation planning system and an NC code post-processor for effective machining of press dies for production of cars. Based on the machining feature, major parts of press dies are categorized into 15 groups and a standard process plan is defined for each group. The standard process plan consists of a series of processes where a process is defined as a group of operations that can be done with one setup. Details such as cutting tools, cutting conditions, and tool paths are decided at the operation planning stage. At the final stage of process and operation planning, the NC code post-processor adjusts feedrates along the tool path to reduce machining time while maintaining the quality. The adjustment rule is selected based on the machining load estimated by virtual machining.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.269-277
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• 1998

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 proceding/succeeding production process including inspection. This approach recognizes that the decision to be made at one manufacturing process (or assembly process) determine not only the cost and the average outgoing quality level of that process but also 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/assembly quality level and sampling inspection plan on the production system, mathematical models and solution technique to minimize the total production cost for a single product manufacturing system with specified average outgoing quality limit (AOQL) are suggested.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.5
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• pp.108-115
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• 2000

This paper presents a variant type process planning system for machining of dies for auto-body production. Through the analysis of dies and their manufacturing processes, the authors categorized the press dies into 15 groups according to the similarity of machining features. After critically reviewing current manufacturing procedures, a standard process plan was defined for each group. The authors present MP3D the process planning system built on the standard process plan database, and show how they apply it at the die manufacturing plant of an automobile company. MP3D is expected to reduce major losses in machining such as reworking caused by mistakenly uncut features and eventually to help to accumulate the knowledge of operators. The operation sheet MP3D produces is also used in monitoring the progress of manufacturing of dies. This paper explains the whole development cycle of a process planning system from process analysis to application so that it can help readers to develop and apply a process planning system to their machine shops.

• Journal of Industrial Technology
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• v.18
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• pp.139-148
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• 1998

Traditionally, the problems of manufacturing technology and manufacturing management have been treated independently. In this research, we endeavor to integrate the process planning and scheduling activities as an attempt to integrate the two realms. To draw up a plan of process planning and scheduling in real manufacturing environment is not an easy task because available time to plan could be limited and the shop status could change frequently. So we propose an architecture of integrated process planing and scheduling problem within the allowed time even if sheep situations change rather frequently. We argue that we can obtain a better and practical scheduling solution by dynamically changing the processing machines and operations as the shop condition changes. The proposed system takes the initial information for alternative machines and operations represented by an AND/OR graph as its input. Other informational inputs to the system are part order and shop statues. The system then generates new process plan and schedules during permitted time. Experimental results show that the proposed scheme provides a viable solution for real world scheduling problems.

• IE interfaces
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• v.11 no.2
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• pp.159-176
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• 1998

In the motor manufacturing system with the properties of short delivery and order based production, the process plan is performed individually for each order by the expert of process plan after the completion of the detail design process to satisfy the specification to be required by customer. Also it is hard to establish the standard process plan in reality because part routings and operation times are varied for each order. Hence, the production planner has the problem that is hard to establish the production schedule releasing the job to the factory because there occurs the big difference between the real time to be completed the process plan and the time to be required by the production planner. In this paper, we study the decision supporting system for the process plan based on knowledge base concept. First, we represent the knowledge of process planner as a database model through the modified POI-Feature graph. Then we design and implement the decision supporting system imbedded in the heuristic algorithm in the client/server environment using the ORACLE relational database management system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.4
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• pp.1-2
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• 2013

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.46
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• pp.119-125
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• 1998

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 / succeeding production process including inspection. This approach recognizes that the decision to be made at one manufacturing process (or assembly process) determine not only the cost and the average outgoing quality level of that process but also 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 / assembly quality level and sampling inspection plan on the production system, mathematical models and solution technique to minimize the total production cost for a single product manufacturing system with specified average outgoing quality limit(AOQL) are suggested.