A Development of Flexible Manufacturing System ... - ScienceDirect

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ScienceDirect Procedia Manufacturing 2 (2015) 77 – 81

2nd International Materials, Industrial, and Manufacturing Engineering Conference, MIMEC2015, 4-6 February 2015, Bali Indonesia

A Development of Flexible Manufacturing System using POLMAN T-100 Vise Casting Component as a Case Study Mohammad Nurdin*and Angga Lukmanul Hakim Polytechnic of Manufacturing of Bandung, Jalan Kanayakan No.21, Bandung 40135, West Java, Indonesia

Abstract Now a day and future challenges in industrial activity is the ability of speed and precision to produce a product and provide services in a wide range of demands which are always want to customize. This is often faced as an industrial problem, especially if associated with the price and speed to the market (delivery) competition, it should better than the competitor. So the total unit cost has to become lower, delivery time faster and the product life cycle shorter significantly. This problem is often solved with the building automation system to produce products with customized, but the process cost is near to mass production, of course the target speed and accuracy will remain achieved. One of the automation systems in the manufacturing sector is Flexible Manufacturing System (FMS) for complex components with diverse (multi) variations machining process. This system was created as a method in producing goods which can readily adapt to the product changes and should be capable to produce goods in various levels of production. It is necessary to prove that this system can achieve a better level of productivity compared to conventional method; in this case it will be taken a case study of POLMAN T-100 vise casting components by developing an own FMS which is fit to that product. This paper will explained how the FMS works by designing the configuration and performance in its elements; and simulated in producing vice casting components for 200 pairs of POLMAN T-100 vice casting product compare to the existing conventional methods. The result that FMS can produce 4 pairs of vice casting components in 3.8 hours, this mean round 20 times bigger than conventional method which it needed more than 73 hours, this FMS performance is calculated only in one long shift (10.5 hours/day), and this will be higher when it normally for FMS standard calculated in 24 working hours/day. That result is very reasonable, because FMS use machining center and material handling system (MHS) even it can run automatically with less human contact. © 2015 2015The TheAuthors. Authors. Published by Elsevier B.V. © Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license Selection and Peer-review under responsibility of the Scientific Committee of MIMEC2015. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Selection and Peer-review under responsibility of the Scientific Committee of MIMEC2015 Keywords: flexible manufacturing system, industrial automation system, mass customization manufacturing and productivity

* Corresponding author. Tel.: +62 22 250 241/+62 81 121 0256; Fax:+62 22 250 2649. E-mail address: [email protected] or [email protected]

2351-9789 © 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Selection and Peer-review under responsibility of the Scientific Committee of MIMEC2015 doi:10.1016/j.promfg.2015.07.013

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Mohammad Nurdin and Angga Lukmanul Hakim / Procedia Manufacturing 2 (2015) 77 – 81

1. Introduction Increasing global competition has evolved a manufacturing environment which gleans vast product variety, reduced manufacturing lead times, increased quality standards and competitive costs. Simultaneously, with a rising trend toward globalization, these manufacturing environments must be designed to cater new challenges to survive and grow in the marketplace [1]. Today, competition in the manufacturing industry over the next decade will be focused on the ability to flexibly and rapidly respond to changing market conditions with significantly shortened product life cycles [4]. This makes the manufacturing environment is becoming more competitive; it is necessary needed an idea of new manufacturing systems to meet new challenges in order to survive and keep growth in the market. To overcome these diverse issues, its needed technology support in improving the flexibility and automation to improve the manufacturing environment as a main reason for the introduction of Flexible Manufacturing Systems (FMS). A new strategy was formulated (Customizability), the companies have to adapt to the environment in which they operate, to be more flexible in their operations and to satisfy different market segments. Thus the innovation of FMS became related to the effort of gaining competitive advantage [3]. FMS as a cellular manufacturing is an application of group technology in the manufacturing process. In this paper is presented a case study to find some method to increase the performance of manufacturing systems. This study is based on a model of manufacturing in estimating performance parameters such as maximum production levels; timelines and overall handling time utilization. Through this study, sought also to present the design of a flexible manufacturing system that may be made for small scale industry which are the design and performance parameters are adjusted and compared with existing FMS. 2. Literature Review Flexible Manufacturing System (FMS) is a group of several machines or process dedicated to produce a group of objects that common which the ability is flexible for a similar group objects in process, such as their operation, tolerance, and the capacity of the machine tool. It called flexible because it has good flexibility in machine capability, these sequences or alternative in process, product, production, and its development. The consideration of FMS as production system is flexibilities ability and the characteristics as well as the production system for product variations. Flexibility is the foundation and concepts which used in the design of modern automated manufacturing systems, as well as on FMS. Flexibility can be defined as a collection of manufacturing systems character that support a change in the activity or production capabilities. In recent time FMS emerged as a powerful technology to meet the continuous changing customer/product demand. Increase in the performance of FMS is expected a result of integration of shop floor activities such as machine and vehicle scheduling/AGV [9]. These are several flexibilities ability which can be shown from the FMS: Machine Flexibility, reflecting the ability of the machine to make the necessary changes in producing a number of types of components available. Sequence Flexibility, the ability to handle the production or assembly through an alternate route, and the ability to handle or stopping an activity, for example: machine breakdown or replacement tool, and resume production. Process Flexibility, the ability to produce the variety mixture of similar products which are using machine center. Product Flexibility, ability to change/exchange into new products economically and quickly (the product changes includes design, fixture, etc., and changes can be done quickly and only can be done by utilizing the principles of group tech.). Production Flexibility, ability to carry out the production of a number of pallet types without additional investment for major equipment. Development flexibility, the ability to develop/ expand an existing FMS, as needed, easily and in a modular form. The description of relationship between the volume of products and product variations that must


be completed in a manufacturing process is shown in the figure-1 above, where the FMS has the following characteristics: x Used in the production system which product quantity low to moderate volume. x Can be used with a variety of products in a batch production x The manufacturing process is done without a central computer, and x More flexible than the manufacturing cell. 3. Description of Case Study and Problem Definition 3.1. Product Identification (Case Study) For a case study in the development of this FMS used POLMAN T-100 vise through comparing process method between conventional and FMS for casting components only, namely fixed jaws and moving jaws. The casting (see fig. 2) has 3 mm machining allowance and cast iron material (JIS FC250/DIN 0.6025). 3.2. Conventional Method Milling machine and drilling machine are used for conventional method with special Jig and Fixture (JF) as a guiding tool in producing casting component of POLMAN T-100 vice which the processing type is always in batches. Moving Jaws Moving Jaw is processed using its JF which has designed according to the clamping requirement by considering cutting direction for precise result and uniform purpose even if it in large quantities (consistent). The process time (one moving jaws) is 610 minutes which are consist of 455 minutes for cutting time and 155 minutes for non-cutting time. Fix Jaws The fix jaws is also processed using conventional method, its same with moving jigs using jig and fixture which has been tailored to the requirement of working processes to achieve the accuracy and consistency in large quantities. The duration of manufacturing process for one fix jaw using conventional method is 710 minutes. Consist of 510 minutes of cutting time and non-cutting time is 200 minutes. The JF changing in conventional method is caused a non-cutting time becomes longer, so the JF usage is not effective enough to shorten the processing time. 3.3. Flexible Manufacturing System (FMS) FMS method for producing POLMAN T-100 vise is supported by CNC Machining Centers and Material Handling System (MHS). The MHS is an integration system of Bridge, Conveyors and Automated Guided Vehicle (AGV); as well as JF and tower blocks for clamping the casting product in a modular pallet. Horizontal CNC Machining Center Horizontal Machining Center (M-type H4BN) has characteristics are high productivity and ability to produce products quickly which have 40 m/min Rapid Traverse, Automatic Tool Changer (ATC) system for tool-to-tool (1.3 sec) and chip-to-chip (3.8 seconds), and Automatic Pallet Changer (APC) system (6.0 sec) with table indexing speed (2.5 sec/90o). Furthermore, this machine is equipped with two pallets outer size 400 x 400 mm with 24 holes completed by M16. Bridge Bridge is additional equipment which is built fit to the existing CNC machines. The objective is bridging tower blocks from AGV to the CNC palette system and on the contrary after machining of product finished. Conveyor Storage (2)

Storage-1 for the material casting storage and Storage-2 for finished product storage.

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Automated Guided Vehicle (AGV) AGV as a transporter has a function to take a pallet from conveyor storage to place it in the bridge of CNC machine; and contrary after the process in CNC complete, AGV will take the pallet to place it back in the finish product conveyor storage. The AGV movement time can be seen in the table below. The AGV movement is MHS main time of FMS method. Tower Block and Jig & Fixture (JF) JF are mounted in tower block which is designed in modular system to be easily used for the other product. Tower block is the holder and also as JF parent and it will be installed four similar JF to facilitate processing on CNC machines. 3.4. FMS Lay-out The FMS lay-out (Fig.3) can be describe as follows: 1. Conveyor storage for material serves 2. AGV (transporter) for taking and transporting the material from the conveyor to the CNC machine center and contrary take it back to finished product storage conveyor. 3. CNC machining center for machining processes. 4. Conveyor storages for finished product Table 1. List of FMS Method Activities Node

Activities

A B C D E F G H I J K L M N O P Q R S T U V W X

Clamping MJ1 and FJ1 on STG1 AGV take & place MJ1 to CNC Rotating CNC Pallet Cutting MJ1 in CNC AGV take & place FJ1 to CNC Rotating CNC Pallet Cutting FJ1 in CNC AGV take & place MJ1 to STG2 Un-clamp MJ1 and then clamp MJ2 AGV take & place MJ2 to CNC Rotating CNC Pallet Cutting MJ2 in CNC AGV take & place FJ1 to STG2 Un-clamp FJ1 and then clamp FJ2 AGV take & place FJ2 to CNC AGV returning TB to STG1, move to CNC Rotating CNC Pallet Cutting FJ1 in CNC AGV take & place MJ2 to STG2 AGV move to CNC Rotating CNC Pallet AGV take & place FJ2 to STG2 Un-clamp FJ2 Un-clamp MJ2

Precedence T (min.) A B C A&B D&E F F H I G& J K K M N O L& P Q Q S R&T U V S

20.00 1.06 0.10 13.48 0.92 0.10 34.82 0.81 20.00 0.81 0.10 70.48 0.81 20.00 0.81 1.81 0.10 77.36 0.81 0.21 0.10 0.81 10.00 10.00

3.5. FMS Operation Plan The operation plan is a sequence of activities in producing POLMAN T-100 vise which is starting from mounting/clamping work-pieces on the tower block and the end is the finished product un-clamping. The total operation time of FMS method through sequence of events in the operation plan to produce 4 pairs of POLMAN T-100 vise is 228.52 minutes (minus the red node time). This operation time data will be compared with conventional method.

Note: TB (Tower Block), MJ (Moving Jaws), FJ (Fix Jaws), STG1 (Preparation Storage), and STG2 (Finished Product Storage), The Red Node is Parallel Activities, The Blue one is cutting time of CNC.

4. Result The production time length is determined with assume to meet the demand of 200 pairs of POLMAN T-100 vise each month; so simplify the table of activity on the FMS operation plan above to production schedule for 1-cycle (4 pairs vice) and continued to 2-cycles resulted the total time of FMS method 196.54 minutes (see Fig.4)


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Figure 4. Production Schedule for 1-Cycle, 2 Cycle and end Cycle Based on that production schedule, it’s known that there is a pattern of repeated total time per cycle (cycle pattern) which can be developed a mathematic model as shown in the right text box. That mathematic model can be used for producing 200 pairs of vice casting; the total time of FMS method Note: is 9,858.97 minutes or 164.31 hours. Meanwhile for t-start : clamping time of material (earliest time) conventional methods is 3,658.33 hours (22.26 times) t-mc : machining time on the machine centre t-end : turning pallets time (latest and un-clamping time) The operation plan of both manufacturing method t-tr : transportation time (conventional and FMS) has two kinds of time, cutting n : quantity of products pairs time and non-cutting time. If it compared both noncutting time is 770 minutes for conventional methods and 89.4 minutes for FMS method (where this non-cutting time is also partly/overlap in cutting time), so it is made FMS method more giving positive impact to the productivity. 5. Conclusion The calculation of data processing can be concluded for FMS method compare to conventional method: x More than 22 time faster for producing 200 pairs of POLMAN T-100 vice casting product. x Material handling time is 5.14 times faster within 1-cycle of production. x Reduced contact with the operator, even after the material are ready, the FMS can run automatically The result of this calculation of FMS performance should also be assessed in terms of economic viability, its mean that the additional investment and the use of material handling and machining center of course will higher than conventional method. But, at least it is known the FMS method is better to increase the productivity although it will be more expensive cost per hour of FMS method. This will be realistic if FMS method ran in mass production scale. References [1]. Ajay Singholi, D. C. Toward improving the performance of flexible manufacturing system: a case study, Guru Gobind Singh Indraprastha University, India, 2010 [2]. Ali S. Kiran, S. A. Tardiness heuristic for scheduling Flexible Manufacturing Systems, Department of Engineering Management, University of Missouri, Sandiago, 1989 [3] H.K. Shivanand, M. B. Flexible Manufacturing System, New Age International (P) Ltd, Publisher, New Delhi, 2006 [4] Guixiu Qioa, R. L., Flexible Manufacturing System for Mass Customization Manufacturing. Gaitherrsburg, Manufacturing Systems Integration Division, National Institute of Standard and Technology [5] Kodeekha, E. Case Studies for Improving FMS Scheduling by Lot Streaming in Flow-Shop Systems. Acta Polytechnica Hungarica, Budapest, 2008. [6] Kulatilaka, N., Valuing The Flexibility of Flexible Manufacturing Systems, School of Management Boston University, Boston, USA,1988. [7] Mize, C. B., Scheduling and Control of Flexible Manufacturing Systems, Department of Management Systems, University of Waikato, Acritical Review. Hamilton [8] Reddy, B. S., Flexible Manufacturing Systems Modeling and Performance Evaluation Using Automod, Department of Mechanical Engineering, Kakatiya Institute of Technology & Science, Warangal-15, A.P., Kakatiya, India, 2011 [9] Salzman, R. A. Flexible Manufacturing Systems and Value Stream Mapping, Department of Mechanical Engineering, Massachusetts Institute of Technology, Massachusetts, 2002.