Redesign of Existing Layout of Tiller Manufacturing Industry to Reduce Material Handling Cost

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1 IJSTE - International Journal of Science Technology & Engineering Volume 2 Issue 4 October 2015 ISSN (online): X Redesign of Existing Layout of Tiller Manufacturing Industry to Reduce Material Handling Cost Dileep Pandalai PG Scholar Department of Industrial Engineering & Management, Mangalam college of Engineeering Ettumanoor Subin George Mathew Assistant Professor Department Of Mechanical Engineering Mangalam college of Engineeering Ettumanoor Abstract The aim of this paper is to support a tiller manufacturing industry to find out the best layout for their machine shop so that the materials need to travel minimum distance in the machine shop and to find out the reasons that are obstructing them to meet the demand. The plant is designed to manufacture all the parts required for tiller. But currently most of the parts are outsourced. Due to this reason the parts currently manufactured in the plant needs to travel long distances in the machine shop. The company is not able to meet the demand for the last few years. So this paper proposes a method to improve the productivity by modifying the machine shop and other required stations. Keywords: FLP, Pair-wise interchange method, CRAFT, ARENA Simulation, Machine shop I. INTRODUCTION Plant layout is a floor plan for determining the desired machines and equipment of a plant whether established or contemplated in the one best place to permit the quickest flow of material at the lowest cost and with the least amount of handling in processing the product from the receipt of raw material to the shipment of finished product. Facility Layout Problem (FLP) is known as to have a significant impact upon manufacturing costs, work in process, lead time and productivity. II. NEED FOR REDESIGN When discussion starts about plant layout usually, papers link it with planning an entirely new plant starting from the scratch. Layouts are designed for new plants and this is not the case always. Problems are there which necessitate the improvement and revision of existing layouts also. There are many reasons which make management to think to redesign the existing layouts. For example Expansion of capacity, Shrinkage of output, Change in product design, Replacement of equipment, Entire department moved to new location, Poor work environment, Frequent accidents, To reduce material handling costs, To reduce other costs Here in this paper we are focusing on the requirement of facility layout planning, in order to reduce the material handling cost and reduce the travel time and distance covered by the product before it gets in to the final product. III. LITERATURE SUMMARY Filippo De Carlo, Maria Antonietta Arleo, Orlando Borgia and Mario Tucci 2013[1] explain that one of the main goals of a manufacturing system is the maximization of its productivity. The challenge of determining the best arrangement of the workstations is one of the elements that has a great impact on system performance. According to Annant Dhawan 2004[2}, says that the design of a facility is a strategic issue that is having significant impact on the manufacturing units. It is essential to reallocate the plants equipment in a way that they do not alter the manufacturing process but reduces the distance between different workstations which in turn reduces the material handling cost. Bobby John, Jubin James, R. Mahesh Rengaraj 2013[3] explains the use of Computerized Relative Allocation of facilities Technique (CRAFT) for the reallocation. Russell D Meller and Kai-Yin Gau 1996 [4] explain the various problems and methods available to solve the problems associated with the plant layout. The detailed layout problem includes flow line layout problems, machine layout problems, and cellular manufacturing, design problems, where machines are assumed to be of equal area or of fixed dimensions. According to Jia Zhenyuan, Lu Xiaohong, Wang Wei, Jia Defeng, Wang Lijun 2011[5], traditionally, there are two approaches for the facility layout problem. The first one is the quantitative approach aiming at minimizing the total material handling cost between departments based on a distance function. The second one is the qualitative approach aiming at maximizing closeness rating scores between departments based on a closeness function. R.D Vaidya 2013[6] explains that the main workshop characteristics impacting the layout are products variety and volume, facility shapes and dimensions, material handling systems, multi-floor facilities, back tracking and bypassing, pick-up and drop-off locations. productivity. All rights reserved by 228

2 Arash Shahin 2011 [7] proposed an integrated approach of simulation, fuzzy AHP, QFD and MCDM for facility layout design improvement and optimization. The results indicate that the proposed approach enhances problem solving in facility layout, compared to the reviewed literature. While the developed model includes considerable advantages, its application is limited to process layout (job shop). Reuven R Levary 1984 [8] surveys the main characteristics of the most-used solution procedures for facility layout problems. The tabulated characteristics can be used for determining which solution procedure can be applied to a particular problem. The final choice of a solution procedure depends on additional factors such as budget, availability of computer hardware and software and experience of the practitioner with the solution procedure in question. Mahendra Singh 2012[9] explains that facility design is crucial issue for production related decisions. The efficiency and productivity depends on the type of manufacturing layout is being used for production of goods and services. Not only efficiency is increased directly but indirectly good facility layout also contributes to efficiency by reducing accidents, hazards, by increasing easiness and convenience. Ameha Mulugeta, Birhanu Beshah and Daniel Kitaw 2013[10] in their research explain that facilities are crucial as they usually represent the largest and the most expensive assets of an organization. Determining location of machines, workstations, and other facilities are layout problems in a manufacturing plant. Different computerized algorithms have been developed to optimize the flow of materials within a factory. IV. PROBLEM IDENTIFICATION AND PROBLEM STATEMENT The current layout at the tiller assembly unit was built in the 1970s. The factory floor consists of an assembly floor, painting booth and a machine shop. The process starts with the assembly of transmission and engine simultaneously. In the earlier period, all the components required for the assembly are manufactured in the machine shop. But at present only four critical parts are manufactured in the factory. Rest all the components are outsourced through sub-contractors. After observation in the Production unit for few days, the following observations were made. 1) Not able to meet the demand 2) All the equipment in the plant are not used 3) Lot of idle machines in between working machines 4) Unwanted material handling due to improper allocation of machines 5) Raw materials are stacked in between machines Problem Statement - Redesign of existing layout to reduce material handling cost in a Tiller Manufacturing Industry V. PROBLEM DEFINITION The machine shop consists of 44 machines. Most of these machines are special purpose machines manufactured for machining of tiller parts. Out of these machines only 20 machines are currently in operation. These working machines are located at remote positions within the floor. So if we are placing the machines appropriately in one part, the transportation distance the materials have to travel during the manufacturing process can be significantly reduced. A major portion of the factory is occupied by the machine shop. s Total floor area = 4455m 2 Area occupied by machine shop = 1208m 2 (27.11%) Total number of machines in the plant = 44 Number of machines in use = 20 (45.45%) That is 27% of plant floor area is occupied by machine shop out of which 56% of area is occupied by idle machines. That means there is no output from a significant area in the plant. The production and demand details for the past three years are shown in the table below Table - 1 Production and Demand Details for Past Three Years YEAR DEMAND PRODUCTION (TILL AUG) When the output for the past few years was analyzed, it is found that the production is showing a decreasing trend and not able to meet the demand. The table II shows the departments and their area in the existing plant. Table - 2 List of Departments and Area Occupied SN DEPARTMENT AREA (sqm) SN DEPARTMENT AREA (sqm) 1 OFFICES T SUBSTATION T PAINTING BOOTH QA OFFICES QA OFFICE 80 All rights reserved by 229

3 5 TYRE ASSEMBLY M/C SHOP KMB KMB EF KMB TF OFFICES KMB ENGINE ASSY T Table - 3 Distance Travelled By Parts in the Existing Layout PART EXISTING LAYOUT SIDE COVER m GOVERNOR LEVER m CAMSHAFT m OIL SUPPLIER RING m A major area of the plant is occupied by the machine shop where 54% of the available machines are not used. If we redesign the plant layout utilizing the area available by increasing the existing size of the work stations, the overall productivity of the plant can be increased significantly. In order to increase the space available in the plant one possible solution is to remove the unused machinery in the plant which has not been used for long period. Then the best possible arrangement has to be determined for existing machinery. The remaining space can be utilized for expansion of stations with bottle necks. Thus the production can be improved. VI. PROCEDURE A. Stage 1: In this stage the existing plant layout is studied, whether it is optimal or not. For this CRAFT algorithm is used. The inputs for doing CRAFT analysis is given below. Departments and their area (Table 2), Flow matrix, Cost matrix, Fixed departments, Co-ordinates of centroids of departments The existing plant layout is analyzed in CRAFT layout and the result can be summarized as below. Initial cost: 8388 First iteration (Switch 15 and 14): 8224 Second iteration (Switch 15 and 11): 8889 From the second iteration the cost started increasing and hence first iteration give the best layout. The department 15 is machine shop and department 14 is QA offices. There is no material transfer between these departments and the change is irrelevant to our scenario. Hence it is observed that the existing layout is the best layout when all the parts required for the production are manufactured in the factory. But since most of the parts are outsourced, there is a need to re-design the layout for that case. B. Stage 2: From the previous stage calculation, it is clear that there is need for redesigning the layout. Machine shop is the ideal place to start with the modification since it is occupying the maximum area and utilisation is less than 50%. in machine shop already the procedure is fixed. So only thing to be done is to fix the position of the machines such that the products manufactured need to travel the minimum distance. For this pair-wise interchange method is utilised. For doing this calculation a program has been written in Visual basic. The input for this calculation is the From-To chart for the machine shop. From the entire list of operations the machines required for parts currently manufactured are segregated and new chart is prepared and this forms the input. Then it is needed to find out the pair of machines with the maximum number of materials shifted. For ease of calculation we are taking machines are placed unit distance apart and cost of transferring 1 unit is Rs.1. Now another assumption taken here is explained through an example here, if 15 number of parts are transported from A to B and 10 numbers are transported from B to A, then between A and B total transportation done is 25. Like this if it is able to transfer the number to one direction, the resulting matrix will be an upper triangular matrix. From there it is able to find out the maximum number of transportation. Then the first pair of machines are placed in the position 1 and 2. Then the row and columns of both the machines 1 and 2 are checked. The machine having the highest value is placed next and so on. The outcome will be the initial sequence for calculation with minimum cost. The cost of this layout will be All rights reserved by 230

4 q ij is the quantity of parts moved between stations i and j dij is the distance between stations i and j. First iteration and its cost is 1595 and initial arrangement is as follows. Table - 4 Initial Arrangement INSPECTION DEBURRING BFWV2 TAP RM3 Y025 RM4 BFWH1 RD1 FN2V LT20 CAP RTV50 RM5 BFWH2 SFG FNDC H22 KWM CMG K130-1 K130-2 The highest cost is for the pair deburring and RM5 and the cost is 201 (35 X 6). In the second iteration, RM5 is repositioned to position 3 and the other stations are shifted 1 position downwards. Then the arrangement is given in table 5 and the cost is In the next iteration the cost starts increasing and the cost became So the table 5 is the final arrangement for machines. Table - 5 Final Arragement INSPECTION DEBURRING RM5 LT20 BFWV2 TAP RM3 Y025 RM4 BFWH1 RD1 FN2V CAP RTV50 BFWH2 SFG FNDC H22 KWM CMG K130-1 K130-2 Distance Covered By The Parts In Machine Shop After Modifying The Layout The distance travelled by the parts in the parts in the machine shop is calculated after a new layout is drawn in AutoCAD using the new arrangement and is compared with the existing layout. The summary is given in the table below. Table - 6 Comparison of Distance Travelled By the Parts in the Plant PART OLD LAYOUT NEW LAYOUT SIDE COVER m 55.63m GOVERNOR LEVER m 44.32m CAMSHAFT m m OIL SUPPLIER RING m 36.65m C. Stage 3: A model of the process is modeled in ARENA the model is as follows. Fig. 1: ARENA Model of the Process in the Factory All rights reserved by 231

5 The model is run in ARENA and the output is found out to be In the factory at a time around 5 units are processed and thus the output will become 1196 x 5 = It is also found the queue is generated at stations E1 and T3. This can lead to blockage in the production. VII. RESULT The existing plant layout was analysed using CRAFT and found that it is the best layout when the plant is used to manufacture all the parts required for tiller. Since most of the parts are outsourced, there is a need to redesign the plant. It is done by redesigning the machine shop in which most of the machines are idle and the best arrangement for the currently using machinery is determined. The travelling distance of parts is reduced significantly in the new layout. VIII. CONCLUSION Detailed evaluation of the existing plant layout made it clear that it is having some bottle necks in some stations in two stations and is affecting the productivity. The possibility of modification of the layout lies in the management decision. The management have to take decision regarding whether they are going to make the parts or whether they are going to outsource the parts. If they are going to buy the parts, modification of the layout is possible. In the other case, the present layout is the best possible one. The layout generated after studying in CRAFT and pair-wise interchange method gives significant improvement in the productivity of the plant. REFERENCES [1] Filippo De Carlo1, Maria Antonietta Arleo, Orlando Borgia Mario Tucci, Layout Design for a Low Capacity Manufacturing Line: A Case Study, International Journal of Engineering Business Management Special Issue on Innovations in Fashion Industry, 2013 [2] Annant Dhawan, Dinesh Kumar Kasdekar, Sharad Agrawal, Layout Design and Evaluation using Computer Relative Allocation of Facilities, Proceedings of Thirteenth IRF International Conference, September 2014 [3] Bobby John, Jubin James, R. Mahesh Rengaraj, Analysis and Optimization of Plant Layout using Relative Allocation of Facilities Technique Allocation. IJETAE Volume 3, Issue 8, August 2013 [4] Russell D. Melter and Kai-Yin Gau, The Facility Layout Problem: Recent and Emerging Trends and Perspectives, Journal of Manufacturing Systems Vol 15/No 5 I996 [5] Jia Zhenyuan, LU Xiaohong, Wang Wei, Jia Defeng, Wang Lijun, Design and Implementation of Lean Facility Layout System of a Production Line, International Journal of Industrial Engineering 2010 [6] R. D. Vaidya, P. N. Shende, N. A. Ansari, S. M. Sorte, Analysis Plant Layout for Effective Production, International Journal of Engineering and Advanced Technology, 2013 [7] Arash Shahin, Mehdi Poormostafa, Facility Layout Simulation and Optimization: an Integration of Advanced Quality and Decision Making Tools and Techniques, Published by Canadian Center of Science and Education, 2011 [8] Reuven R. Levary, Sylvia Kalchik, Facilities Layout A Survey solution of Procedures, Comput. & Indus. Engng Vol. 9, No. 2, 1985 [9] Mahendra Singh, Innovative practices in Facility Layout Planning, International Journal of Marketing, Financial Services & Management Research Vol.1 Issue 12, December 2012 [10] Ameha Mulugeta, Birhanu Beshah, Daniel Kitaw, Computerised Facilities Layout Design, Journal of EEA, Vol. 30, 2013 All rights reserved by 232