The Improvement of Production Bottleneck Process in J Company Automobile Assembly Line Yan-Hua MA 1,a, Tian-Rong BAI 1, Ling-Yu LI 1,b,*, Zhen LI

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1 2016 Joint International Conference on Artificial Intelligence and Computer Engineering (AICE 2016) and International Conference on Network and Communication Security (NCS 2016) ISBN: The Improvement of Production Bottleneck Process in J Company Automobile Assembly Line Yan-Hua MA 1,a, Tian-Rong BAI 1, Ling-Yu LI 1,b,*, Zhen LI 1 Institute of Mechanical Science and Engineering, Jilin University, Changchun, Jilin, China a yhma@jlu.edu.cn, b @qq.com *Corresponding author Keywords: Automobile Assembly Line, The Bottleneck Process, MTM Method, The Learning Curve Theory, AHP. Abstract. The 21st century is an era of rapid scientific and technological development, the manufacturing sector, the production methods are constantly undergoing change. Due to the rapid changes in market demand, how to further improve the efficiency of production lines to meet market demand, more and more importance in enterprises. This requires at existing production facilities remain unchanged, continue to solve the production line in the bottleneck problem, to achieve the purpose of optimizing the production line. Based on the J company car assembly line research, industrial engineering according to the method identified limit their productivity bottleneck process and propose ways to improve the process simplified from three aspects, MTM method and the learning curve theory, we have made reduce operating time bottleneck process to take time below the lifting of restrictions on the assembly line productivity. Finally, through analytic hierarchy process evaluation above methods to obtain the most suitable method for improving further propose the optimal solution. Introduction Taking J compay s car assembly line for the study, analysis of the status of its production lines to find their bottleneck process and use the fishbone diagram to system analysis the causes of the problem, and raise the various improvement measures of questions and last identify the most effective method by utilizing Analytic Hierarchy Process, and then give the optimal solution for decision makers. Situation Analysis of J Company s Car Assembly Line Existing Questions of J Company s Car Assembly Line Situation The J company s main products are CA series of mini cars and special vehicles. Currently, the production shifts of assembly plant is one shift, takt time is 3.6 min/station (ie, Takt Time = 216S). During the internship I found it, the former interior Unit is the bottleneck team, and this article analyzed the current operation time of each station of former interior Unit, as shown in figure 1. As it can be seen from Figure 1, AP1, AP6 and AP7 station operating duration, in which operating time of AP1 station has exceeded the tact time.

2 Figure 1. The current operation time of each station of former interior Unit. Analysis the Cause of Bottlenecks Station of J Company s Car Assembly Line After analysing we can known that the operating time of AP1 station is too long, and it has become a bottleneck, in order to provide the basis for the after propose ways, here we analysis its causes with the fishbone diagram, as shown in figure 2: Figure 2. the fishbone diagram of bottleneck process. Next, this paper will propose specific ways, according to the above analysis. Proposed Improvement Measures from Different Angles Simplify the Process Method Be ECRS questions for each operation bottleneck AP1 station, according to the results of questions, make recommendations for improvement as follows: 1) The work instructions to take place in the vicinity of frame material of the front and rear door glass (formerly 2), so that the operator eliminating the two-part walking time St1which refers to the need to work instructions ; 2) The glass bead and glass frame are placed on both sides of production lines, to reduce walking time St2: St2 5.05s ( ie, the time of operator walk to the dispensing station). 3) Improve the placement of material shelf of back door buckle license board, to make it more reasonable and to reduce the auxiliary time and move to 5.00S. then examine the total station work TAP2 of AP2: T 168s 5.00s 37.47s s 216 At

3 T T st1 st2 T, s s 216 By simply redistribute station content, and streamline operations, operating time of AP1 station operating time is less than tact time. MTM-UAS Method to Improve the Operation MTM-UAS method is very suitable for assembly line of a predetermined time standard of operation by regulating the operation of the operator to make it more in line with the principles of motion economy, the improved MTM-UAS analysis table is shown in table 1: Table 1. The time of after improvement by MTM-UAS method. J compay the assembly line AP1 station The main job description: 1, parts will be assembled into a glass front door assembly, complete the front door glass installation; 2, to assemble the parts into a glass back door assembly, complete the installation of the back door; 3, complete the back door buckle license card installation. Job No. Work Process Action Coding value Frequ ency total To glass assembly workbench by going 3 steps. KA Time /s 1 Take the front door glass. AC Put the front glass on the table. PB Take the glass holder and glass bead. AC Put the glass holder and glass bead on a table. PB Put the glass holder installed in the appropriate location of the front door glass. ZA Take compression fittings of pumping press. AC Pressed glass holder (four points) with compression fittings of pumping press. HC Take a rubber mallet. AC Glass holder with a rubber mallet to further pressed against the glass front door, to form a front door glass assembly. BB Pick up the glass front door assembly. AC To the automotive products by going 5 steps. KA Install the front door glass assembly. BB To glass assembly workbench by going 4 steps. KA Take back door glass. AC Put the back door glass on the table. PB Take the glass holder and glass bead. AC Put the glass holder and glass bead placed on a table. PB Put the glass holder installed in the appropriate location of the rear door glass. ZA Take the press nip pumping means. AC Pressed glass holder (four points) with compression fittings of pumping press. HC Take a rubber mallet. AC

4 Table 1. The time of after improvement by MTM-UAS method (Cont.). J compay the assembly line AP1 station The main job description: 1, parts will be assembled into a glass front door assembly, complete the front door glass installation; 2, to assemble the parts into a glass back door assembly, complete the installation of the back door; 3, complete the back door buckle license card installation. Job No. 7 Work Process Glass holder with a rubber mallet to further pressed against the glass rear door, to form a front door glass assembly. Action Coding value Frequ ency total Time /s BB Pick up the back door glass assembly. AC To the automotive products by going 4 steps. KA Install the rear door glass assembly. BB To the material frame of the back door buckle license card by going 1steps. KA Take the back door buckle license card. AF To glass assembly workbench by going 1 steps. KA Install the back door buckle license card. BB Total 4785 After improving in this section to reduce the number of of AP1 station workers to the 4785 (normal time, together s), take liberalization was 20.5%, improved standard time is: Standard time % s 216 Visible, the operating time of AP1 station is reduced to the below of the tact time, reaching the purpose of eliminating the bottleneck process. The Plant Personnel Policy Adjustments Which Is Based on Learning Curve Theory Taken in May 2015 the production of a single product work as Y1, cumulative production doubling index as n1, cumulative production as X1 = (vehicles); after a period of time (here taken in August 2015) working hours as Y2, cumulative production doubling index as n2, the cumulative production of X2 = (vehicle), there are: Y K C. (1) Y K C. (2) United Vertical (1) and (2) can be obtained: Y Y C Y C. (3) Where: K-- first production of products consumed hours; X--The number of products of cumulative production; C-- learning rate, taking C = 0.85; Y-- production of products required hours of Article X times; n-- cumulative production doubling index. Put the above data into the equation (3), you can get: Y Y C s s. (4)

5 That is the end of August 2015, the station AP1 expected operating time is s, lower than the tact time and eliminate production bottlenecks processes. The Evaluation of Method for Improving According to the evaluation, the superiority of the final ranking obtained as shown in table 2: Table 2. Comprehensive Evaluation table. B1 B2 B3 B4 B Sequence C C C C Sort the table by the evaluation shows that C3 method (ie, MTM-UAS action to improve the law) is the best method. Conclusion 1) According to the results of 4.1, for J company, if it does not have the conditions for a short time while implementing a variety of ways to improve, we can only use MTM-UAS sets standards time for the relevant bottleneck stations. 2) If J company has simultaneously a variety of ways to improve the condition, it is best from the human, machine, material, method and environment five aspects of an overall improvement, according to a variety of ways of the foregoing to improve, combined with J company car assembly line the actual situation, put forward specific proposals as shown in table 3: Table 3. J Company Situation improvement plan. Improve angle Specific ways Purpose Site improvements Do a good job in site management 5S work Provide a good production environment Action to improve the operation Using MTM-UAS sets standards time for bottleneck stations Regulate the operation of the operator actions Factory system improvement Staff policy improvements Improve employee learning rate and passion Reference [1] Rafael Pastor, Ignacio Chueca, Alberto García-Villoria. A heuristic procedure for solving the Lexicographic Bottleneck Assembly Line Balancing Problem (LB-ALBP) [J]. International Journal of Production Research, 2012, 507. [2] Hung-Nan Chen V., Jeffery K. CochranV. Effectiveness of manufacturing rules on driving daily production plans [J]. Journal of Manufacturing Systems, 2013, 244. [3] Chen Zhang, Shengsheng Wang. A Dynamic Interval Based Circular Safe Region Algorithm for Continuous Queries on Moving Objects [J]. Int l J. of Communications, Network and System Sciences, 2014, [4] Kevin Caskey, Richard Lee Storch. Heterogeneous dispatching rules in job and flow shops [J]. Production Planning & Control, 2013, 74.