Comments
Transcript
Management & Engineering Simulation System
Management & Engineering 01 (2010) 1838-5745 Contents lists available at SEI Management & Engineering journal homepage: www.seiofbluemountain.com Research on Equipment Maintenance Spare Parts Allocation Simulation System Yanjun Liu*, Wei Wu, Chengming He Department of Technical Support Engineering, Academy of Armored Forces Engineering, Beijing, China KEYWORDS Maintenance level, Product structure, Support processes, Maintenance spare parts, Allocation model ABSTRACT This paper posed the decomposition theory of equipment product structure based on the Level of Repair Analysis (LORA), and analyzed the maintenance support processes of different maintenance level. Then according to the technology of Failure Mode Effect and Criticality Analysis (FMECA), this paper established the equipment maintenance spare allocation model and simulation system. This paper provides decision-making rationale for analyzing the maintenance support processes and determining the maintenance spare parts and allocation concept. © ST. PLUM-BLOSSOM PRESS PTY LTD 1 Introduction Equipment is made up by a large number of parts through different connection ways. During the using stage, all of the parts may be failure, and cause the equipment fault. So we should allocate a certain quantity of maintenance spare parts when deployed the equipment. According to the technology of Reliability-Centered Maintenance Analysis (RCMA), the scheduled maintenance may be classified as organizational, intermediate, and depot. When the equipment was used in a certain time or a certain mileage, according to the functional status of equipment, we should implement scheduled maintenance at different maintenance levels to ensure that the equipment is in good functional status. Spare parts required for scheduled maintenance were allocated according to scheduled maintenance base by higher authorities based on maintenance plan. Therefore, determining spare parts required for planned maintenance was based on maintenance support system, and with some certainty. When allocating the maintenance spare parts, we should allocate a certain number of non- scheduled maintenance spare parts, besides the spare parts required for scheduled maintenance, to ensure that fault equipment can timely access to the required maintenance spare parts and be repaired timely and effective, when the equipment breakdown during the process of using. This paper focused on studying the problem of allocating the non-scheduled maintenance spare parts, according to the decomposition theory of equipment product structure based on the Level of Repair Analysis (LORA). 2 The Decomposition Theory of Equipment Product Structure Based on the Level of Repair Analysis (Lora) 2.1 Related definitions * Corresponding author. Email : [email protected] English edition copyright © ST. PLUM-BLOSSOM PRESS PTY LTD DOI:10.5503/J.ME.2010.01.007 40 Definition 1 The level , divided by the unit- level of responsible for maintenance tasks, which discriminated by the scope and depth of equipment maintenance tasks and the place of maintenance, is called the maintenance level. Maintenance level may be classified as organizational level, intermediate level, and depot level. Definition 2 Based on the restrictions of maintenance level, according to the equipment product functional structure, the equipment was decomposed until all the underlying decomposition unit parts can be repaired at the maintenance level, and constructed the equipment product tree based on the maintenance level. This decomposition theory is called the decomposition theory of equipment product structure based on Level of Repair Analysis (LORA). The same equipment implemented the product structure decomposition at different maintenance levels. But the result is not the same. The repair capacity of maintenance level is more powerful, the level of product structure decomposition is more low, and the underlying decomposition unit parts is more many. For example, a component A, the limited maintenance level is intermediate level, so when we decompose the equipment at the organizational level, we can not decompose the component A, and when the component A is failure or damaged, the maintenance unit of organizational level can not repair it, and can only replace it, then convey it to the maintenance unit of intermediate level. So the component A need to be stored by the maintenance unit of organizational level. However, when we decompose the equipment at the intermediate level, we need to continue decomposing the component A until all the underlying decomposition unit parts can be repaired at the depot level. 2.2 Basic steps of the decomposition theory of equipment product structure based on Level of Repair Analysis (LORA) The decomposition theory of equipment product structure based on Level of Repair Analysis (LORA) is based on the product functional structure decomposition, and begins from the top to the bottom to decompose the equipment according to the maintenance level. The decomposition can be carried on by the follow tow steps: first, we should execute the product functional structure decomposition until the decomposed parts can not be decomposed. Second, we should determine the maintenance level of the decomposed part in different levels from the top to the bottom, then we can gain the underlying decomposition unit parts. Taking some type equipment A for example, the product functional structure decomposition was shown in Figure 1 (a). To component C4, for example, when decomposed the equipment at the intermediate level, if the component C4 can not be repaired at the intermediate level, we should take the component C4 for the underlying decomposition unit part, and component C4 need not be decomposed. The equipment product structure decomposition tree diagram based on intermediate level is shown in Figure 1 (b). A B1 A B2 …… C1 C2 C3 …… …… …… B3 B1 …… …… C4 D1 D2 …… E1 B2 B3 …… C1 C2 C3 …… …… …… C4 D3 …… E2 (a) equipment product functional structure (b)equipment product structure decomposition decomposition tree diagram tree diagram based on intermediate level Figure 1 Equipment product structure tree diagram 3 Equipment Maintenance Spare Parts Allocation Model 3.1 Process of equipment maintenance support Clearing the process of equipment maintenance support is the basis for determining the equipment maintenance spare parts. When equipment is failure or damaged, we should convey the equipment to the maintenance unit of organizational level. Through the fault 41 detection, localization, and isolation techniques to determine equipment failure units, base on the equipment product structure decomposition at organizational level, we can determine the maintenance level of the failure units. If the maintenance unit of organizational level has the ability to repair the failure units, we should take the well-repaired for the failure units by the maintenance unit of organizational level, according to the maintenance manual to determine the repair technology and the required maintenance support resource. Required spare parts for maintenance were supplied by the spare parts warehouse of organizational level. The repaired equipment convey to the organizational unit. If the maintenance unit of organizational level can not repair the failure units, we should convey the failure units or the equipment to the maintenance unit of intermediate level, and based on the equipment product structure decomposition at intermediate level, determine the failure units whether can be repaired at this maintenance level. If the failure units can be repaired by the maintenance unit of intermediate level, we should take the well-repaired for the failure units by the maintenance unit of intermediate level, according to the maintenance manual to determine the repair technology and the required maintenance support resource. Required spare parts for maintenance were supplied by the spare parts warehouse of intermediate level. The repaired equipment convey to the organizational unit. If the maintenance unit of intermediate level can not repair the failure units, we should convey the failure units or the equipment to the maintenance unit of depot level, and based on the equipment product structure decomposition at depot level, according to the maintenance manual to determine the repair technology and the required maintenance support resource. Required spare parts for maintenance were supplied by the spare parts warehouse of depot level. The repaired equipment convey to the organizational unit. The process of equipment maintenance support at the organizational level is shown in Figure 2. organizational unit output fault equipment convey maintenance unit of organizational level fault detection, localization, and isolation determine failure units equipment product structure decomposition based on organizational level determine maintenance level maintenance manual (determine the repair supply the technology and the technology required maintenance support resource) repair convey to maintenance level the failure units or the equipment which can not be repaired at organizational level the spare parts warehouse of organizational level supply themaintenance spare parts well-equipment Figure 2 : The process of equipment maintenance support at the organizational level 3.2 Spare parts allocation model based on the process of equipment maintenance support Based on clearing the process of equipment maintenance support, according to the technology of Failure Mode Effect and Criticality Analysis (FMECA), we can built the spare parts allocation model based on the process of equipment maintenance support. 3.2.1 Determine the underlying decomposition unit parts set According to the decomposition of equipment product structure based on Level of Repair Analysis (LORA), we can determine the underlying decomposition unit parts set I at different maintenance level. I I1 ; I 2 ;; I n , The I i in here stands for the underlying decomposition unit parts. n is the total number of the underlying decomposition unit parts. 3.2.2 Determine the mapping set between the underlying decomposition unit parts and failure mode Taking the underlying decomposition unit part I k for example, we can carry out the Failure Mode Effect and Criticality Analysis (FMECA) to part I k , and determine the mapping set between the underlying decomposition unit parts and failure mode. I k I k M k ,1 k ,1 ; I k M k , 2 k , 2 ;; I k M k ,m k ,m 42 Where M k , j = the failure mode of the underlying decomposition unit part I k k , j = the failure rate of the failure mode M k , j m = the total number of the failure mode of the underlying decomposition unit part I k 3.2.3 Determine the variety, number and configuration level of the maintenance spare parts Based on the results of the FMECA, through the maintenance manual of the maintenance level, we can determine the repair technology and the required maintenance support resource for each failure mode. Then we can get the variety of the maintenance spare parts at this maintenance level. The level of the maintenance spare parts configuration is as the same as the level of the decomposition theory of equipment product structure based on. Then we can determine the mapping set between the failure mode and the maintenance spare parts: M k , j ( Pk , j ,1 , t k , j ,1 ); ( Pk , j , 2 , t k , j , 2 );; ( Pk , j ,l , t k , j ,l ) Where Pk , j ,l = the required maintenance spare part for repairing the failure mode M k , j t k , j ,l = the number of the required maintenance spare part Pk , j ,l n mmodel of Tthe required maintenance spare part Pl for the equipment in T0 period of time: The number 0 Pl t k , j ,l Fi , j i , j , t dt 0 i 1that j 1some unit put Q sets of equipment into service in T0 period of time, we can get the number model of the required Suppose n spare m maintenance part P T0l for the equipment in T0 period of time: Pl Q t k , j ,l Fi , j i , j , t dt i 1 j 1 0 Fi , j i , j , t = the failure distribution function of the failure mode M k , j Where 4 Equipment Maintenance Spare Parts Allocation Simulation System 4.1 System architecture Equipment maintenance spare parts allocation simulation system is an interactive simulation system by the software way, which sets up on the basis of computer hardware. The system is divided into six layers from top to bottom. The top layer is the Users of the simulation system. User can operate on the three subsystems through the functional platforms and interfaces which provided by the human-computer interaction (HCI) layer. The layer is not transparent to users from the fourth layer. Users need not care about the language and hardware platforms which adopted by the simulation system. The hardware system which is in the bottom is the basis to implement the simulation system. The hardware system provides a unified hardware interface and the same software platform for implementing the software system. System language and system management platform is the method to implement the simulation system. Through the interaction between upper and lower layers, it can achieve the purpose of the simulation system. The system architecture of the software and hardware platform is shown in Figure 3. human-computer interaction basic data maintenance subsystem simulation control subsystem simulation results analysis subsystem system management platform system language platform operating system system hardware Figure 3 : The system architecture of the software and hardware platform 43 hardware implementation Software implementation the user of the simulation system 4.2 System structure and module division Equipment maintenance spare parts allocation simulation system is divided into: basic data maintenance subsystem of the system, simulation control subsystem, and simulation results analysis subsystem. The core part is the simulation control subsystem, which controls the activities of equipment maintenance support and to determine the maintenance spare parts allocation. The basic data maintenance subsystem of the system is the basis for the simulation system, which contains: the result data of equipment product structure decomposition based on Level of Repair Analysis (LORA), the result data of FMECA/the data of equipment maintenance manual, and the data of simulation parameter. The basic data maintenance subsystem of the system provides the necessary data for equipment maintenance support simulation. The simulation results analysis subsystem contains: process shows, results analysis, and results output. It can offer the simulation results and suggestion to equipment maintenance spare parts allocation for user. The logic between every subsystem is shown in Figure 4. the user of the simulation system basic data maintenance subsystem simulation results analysis subsystem The result data of equipment product structure decomposition based on LORA process shows results analysis result data of FMECA results output data of equipment maintenance manual simulation control subsystem simulation schedule control maintenance support process control error detect control Figure 4 The logic between every subsystem 4.3 Simulation process The simulation process is shown in Figure 5. Simulation process contains: building the basic data maintenance subsystem of the system, setting the simulation system parameter, maintenance support process and equipment maintenance spare parts allocation simulation, and dealing with the simulation results. The basic data maintenance subsystem of the system and the simulation system parameter is the basis for operating the simulation system. Maintenance support process and equipment maintenance spare parts allocation simulation contains tow simulation module which operate at the same time domain in parallel. A simulation module is the equipment failure simulation module, the other is the fault equipment maintenance simulation module. After initializing the simulation system, the system operates this tow simulation module in parallel. Through setting the failure rate and failure distribution function, fault equipment is generated in the time domain. Having the fault equipment, the system operates the fault equipment maintenance simulation module under the rules. The fault equipment maintenance simulation module calls the basic data maintenance subsystem of the system based on the maintenance support process, and simulates the equipment maintenance support. Finally, the system generates well-equipment. Then the system will continue to call the equipment failure simulation module under the simulation rules until the simulation ends. In the simulation process, the simulation module of dealing with the simulation results records and analyzes the simulation results in real-time, and outputs the simulation results after simulation end. 44 5 Conclusion This paper posed the decomposition theory of equipment product structure based on Level of Repair Analysis (LORA), and analyzed the maintenance support processes of different maintenance level. Then according to the technology of Failure Mode Effect and Criticality Analysis (FMECA), this paper established the equipment maintenance spare allocation model and simulation system. This paper provides decision-making rationale for analyzing the maintenance support processes and determining the maintenance spare and allocation concept. manipulator the result data of equipment product structure decomposition based on LORA the result data of FMECA /the data of equipment maintenance manual the data of simulation parameter database of simulation system begin simulation domain initializing simulation initializing system simulation mode simulation schedule Maintenance support process and equipment maintenance spare parts allocation simulation equipment failure fault equipment maintenance simulation module simulation module output the simulation results end Figure 5 The simulation process References [1]. Guo Qisheng. Theory of Computer Simulation. Beijing: Economic Science Press, 2002, ( in Chinese) [2]. IEEE Std 1516.1-2000 IEEE Standard for Modeling and Simulation (M&S) High Level Architecture (HLA) Object Model Template (OMT) Specification [S], 2000. [3]. Kosturiak Jan R, Gregor Milan, Simulation in production system life cycle, Computers in industry, 1998, 159-172. [4]. Okuda T, Takashige T, Watanabe I. Simulation System Evaluating the Train Headway on Heavy Traffic Lines, Quarterly Report of Railway Transportation Reasearch Institute, 1993, 119-124. [5]. Xu Zongchang. Supportability Engineering[M]. Beijing: Weapon Industry Press, 2002, 158-165( in Chinese) 45