Tài liệu Time management practice 1

Global Production Engineering and Management International Master Program Vietnamese-German University Report PROCESS ANALYSIS AND OPTIMIZATION PLAN of ELECTRONIC DOOR LOCK ASSEMBLY WORKSHOP IN FISCHER ASIA CO., LTD Class: GPEM 2016 Module: Work and Time Study Lecturer: Dr.-Ing. Marlene Helfert Students: Nguyen Hong Phuc Vu Đuc Toe Lattyar Htun Le Nguyen Dat Long Binh Duong, November 2016 1 Vietnamese-German University Work and Time Study Table of Contents Introduction and motivation .......................................................................................... 4 1 Measurement .......................................................................................................... 4 1.1 Method ........................................................................................................................ 4 1.2 Result ........................................................................................................................... 5 1.3 Discussions and conclusions ....................................................................................... 12 1.4 Conclusion .................................................................................................................. 13 2 Optimization ......................................................................................................... 13 2.1 Method ...................................................................................................................... 13 2.1.1 Identify current Problems ............................................................................................. 13 2.1.2 Approach and Optimization Process ............................................................................. 13 2.1.3 Optimized Process and New Layout ............................................................................. 15 2.2 Result ......................................................................................................................... 18 2.2.1 Line Balancing ............................................................................................................... 18 2.2.2 Develop New Standard Time and Workstation ............................................................ 18 2.2.3 Productivity: .................................................................................................................. 19 2.3 Discussion .................................................................................................................. 19 2.3.1 Explanation for result .................................................................................................... 19 2.3.2 Improvement and Advantages & practicability (viability) ............................................ 20 2.4 Conclusion .................................................................................................................. 20 Reference ..................................................................................................................... 21 Appendices .................................................................................................................. 22 2 Vietnamese-German University Work and Time Study List of Figures Figure 1-1 Current work layout .......................................................................................................... 6 Figure 1-2 Current Assembly Process in the Factory ......................................................................... 7 Figure 1-3: Actual Processing time in compare with Total Activity Time ........................................ 10 Figure 1-4: Timeshare of Activity Time in each Work Station ......................................................... 10 Figure 1-5: Average processing time of two lines ............................................................................. 11 Figure 1-6: Current Assembly Process in the Factory ...................................................................... 11 Figure 2-1: Pre-assembly Process ..................................................................................................... 14 Figure 3-2: Main Assembly process ................................................................................................... 15 Figure 2-3: Optimized process .......................................................................................................... 16 Figure 2-4: New Layout for optimized process ................................................................................ 17 List of Tables Table 2-1 REFA sheet Z2 ..................................................................................................................... 8 Table 2-2 Process Studied ................................................................................................................... 8 Table 2-3 Summarize of Work Station .............................................................................................. 9 Table 3-1: Comparison Between Current Condition and Improved Condition ................................. 18 Table 3-2: Main Assembling Process for one Product ..................................................................... 19 Table 3-3: Productivity of Assembly Line Before and After Optimization ........................................ 19 List of Appendices Appendix 1: Actual activity time in Mainline and Subordinate line ................................................. 22 Appendix 2: Actual Processing time in compare with Total Activity Time and Timeshare of Individual Activities ................................................................................................................... 23 Appendix 3: Average Processing Time .............................................................................................. 23 Appendix 4: Time categorization in 2 processing lines .................................................................... 24 Appendix 5: REFA sheet for Stopwatch Time Study in Work Stations 1 and 2 ............................... 27 3 Vietnamese-German University Work and Time Study Introduction and motivation Vietnam is currently an attractive investment destiny for international companies. Because of low labor cost and large available human resource. However, this trend is diminishing because of the increase salary, inflation and the competition from other developing countries. The only way for companies to survive in this war is to increase productivity and quality without rise in cost. In industrialized countries, automation is the most effective way to reach this goal, however it does not fit Vietnam’s current situation, because of economic, intellectual and political reasons. From this point of view, stopwatch study and heuristic techniques come as a cheaper and more applicable solution in assembly industry. An effective optimization plan can help corporates increase production yield, reduce resources used, in this case time and human force, which then lead to less production cost, more competitive price and stabler quality, all of which are vital in this increasingly fierce market. In this experiment, we measured the processing time in an actual production line in the Fischer Asia Co., Ltd, who are adapting their production line for a new product, the electronic door lock. We suggested a new production layout and process, as well as some working settings for a better work flow and a significant rise in productivity. 1 Measurement 1.1 Method First, we analyzed the structure of the assembly line and drew the plan of the workshop. The work process was also recorded. The working conditions including time of day, workshop temperature, humidity and lighting were measured by using a thermometer and a mobile device. REFA stopwatch time study [REF-2013] was used for observation, determination, and recording of the electronic lock assembly at FISCHER company. The resulting information was recorded by using REFA form. In this form, operational sequences without regular repetitions were not recorded. Operational sequences with regular repetitions of cyclic sequence were recorded using REFA sheet Z2. Class members were divided into 6 groups (From group A to F) to record operational sequence. Group A was in charge of recording operating time at work station 1 and 2. Through stopwatch time study, the working time of each worker was recorded and categorized into four types: execution, idle, additional and transport times [HEL-2016]. The data is then evaluated by using Excel data analysis. Two characteristics parameters of the process, the throughput time and processing time were withdrawn from the analysis. [WIL-2007] Heuristics approach was used for process optimization. All groups observed and recorded the current process at electric keypad assembly line and propose a solution to optimize the current process. 4 Vietnamese-German University 1.2 Work and Time Study Result The product was a cylindrical electronic door lock with 7 buttons for typing of a passcode, and only introduced to the company recently. They have already produced a similar product before, but in different shape (rectangular) size and structure (10 buttons). Workshop The assembly line is placed is in an 5 x 10 m room. The workshop is air-conditioned. The production line includes 10 female workers and one male supervisor. The temperature in the workshop was recorded at 32 degrees C and humidity 68%. There was different lightning condition between work stations and its brightness varied from 100 lumens (subordinate line) to 210 lumens (main line). The product is composed of 22 elements, some of which are soldered together. In pre-assembly stations, the DC motor and circuit board is connected together through two electrical wires. The motor is then put into a hollow tube (shaft). On one end of the axle of the motor, a sprocket is installed. It works as a power transmitter between the motor and the slider. Grease is applied to facilitate the movement of the sprocket. A locking block, which is previously inserted with a spring, and the slider are added. The circuit board is folded neatly to cover up the motor. At the same time, another worker prepares another part of the lock. The main body is the front cover, on which contains 7 hollow holes. 7 buttons are put into those holes. A plastic grid is installed to fix those holes in place. The main circuit board, which is soldered with 2 battery contacting springs before, and the battery holder are successively added. After that, 4 springs are put into the screw holes on the back of the front cover. Those springs helps preventing the screws from auto loosening. In final stages, the shaft is put on the front cover, fixed by 4 screws and covered by a cup. The product is then put into a laser machine for number marking and the process is finished. At some stages, the workers might occasionally check their semi-finished or finished products. 5 Vietnamese-German University Work and Time Study In the workshop, two groups work in parallel. One group (Main Line) includes workers in workstations 7, 8 and 9, who assemble the front cover, shaft and final product (screwing) respectively. The same pattern applies to the other group (Subordinate Line) with workstations 4, 3 and 2. Both groups receive the motors soldered the small board from workstation 6, the locking block from workstation 1, and send assembled products to workstation 10, where the laser engraving machine marks numbers on the locks. In works station 5, each motor is soldered with two wires. 1 2 3 4 5 6 Locking Block Assembling Screwing Shaft Assembling Front-Cover Assembling Small BoardMotor Soldering Wire-Motor Soldering 11 Testing 10 Laser Engraving 9 8 7 Screwing Shaft Assembling Front-Cover Assembling Figure 1-1 Current work layout 6 Vietnamese-German University Work and Time Study Figure 1-2 Current Assembly Process in the Factory After recording process by using REFA sheet Z2 (Appendix 5.), all figures of group A are summarize in a list of process studied (table 2-2) and summarize workstation (table 2-3) 7 Vietnamese-German University Work and Time Study Table 1-1 REFA sheet Z2 Table 1-2 Process Studied Nr 1 Process Shaft (locking block) Time/piece (sec) Measure (sec) C (%) Min value Work Station 10.9 Max value 13.9 12.4 54 11.7 24.25 24 9 22.1 26.4 II 8.96 24 18.1 7.3 10.6 II 46.63 24 6.2 43.7 49.5 II I - Reach spring - Insert Spring into locking block - Release locking block 2 Main I (spring) - Reach housing - Put spring into shaft - Release 4th spring 3 Main II (shaft) - Reach shaft - Add pre-assembled shaft onto housing - Release shaft 4 Main II (screw) - Reach screw - Fix Screw - Release housing 8 Vietnamese-German University Work and Time Study Table 1-3 Summarize of Work Station Workstation I Activity Insert spring into locking block Wait for material Workstation II Time share of activity Activity Time share of activity 77% Put housing in assembly box and put 4 spring into housing 28,3% 23% Add pre-assembled shaft 10,4% Fix 4 Screw 54,3% Repair misaligned screw Total share of processing time Total share of waiting time Total share of time spent for getting/searching parts Total share of time spent for personal allowance Total share of time spent for additional activities other 77% 23% 7% 93% 0% 0% 0% 0% 0% 0% 7% 0% 0% The working time data is represented in three charts below. The first figure compares the actual processing time and total activity time in 10 workstations. The seconds figure shows the percentage of each type of times in each workstation. The last one presents the average processing time of two lines, which is used as data input for optimization. 9 Vietnamese-German University Work and Time Study 100 85.9 79.9 90 80 74.5 72.5 70 55.4 60 50.7 44 48.4 47.4 50 37.4 40 20 35.4 29 32.7 24.8 22.4 30 16.1 12.4 45.4 20.3 14.3 10 0 1 2 3 4 5 Processing time 6 7 8 9 10 Total Activity Time Figure 1-3: Actual Processing time in compare with Total Activity Time 100 90 7 23 14.5 9.9 10.3 12.5 80 4 9.3 5.7 21.7 30.3 68.8 60 50 40 3.2 11.3 54.6 70 8.9 93 77 85.5 77.2 2.6 5.5 82 68.4 30 20 86.7 60.9 37.4 28 10 0 1 2 3 4 Execution 5 Idle 6 Additional 7 8 9 10 Transport Figure 1-4: Timeshare of Activity Time in each Work Station 10 Vietnamese-German University Work and Time Study 30.5 Laser Engraving 51.7 Final Assembly 45.2 Front Plate Assembly Shaft Assembly 40.9 12.4 Locking Block Insertion Motor - Board Soldering 14.3 Wire - Motor Soldering 22.4 Spring - Board Soldering 22.0 0.0 10.0 20.0 30.0 40.0 50.0 60.0 Figure 1-5: Average processing time of two lines Two characteristic parameters of the process performance are calculated. In the main line, throughput time is 380.7 seconds, and in subordinate line 364.9 seconds. Processing time of two lines are 224.3 and 266.3 seconds in the same order. Pre-assembled 6 Big Board – Spring Soldering 5 Frontcover Assembling Wire – Motor Soldering Small board – Motor Soldering 4 7 1 3 8 Put spring to locking block Shaft Assembling 2 9 Put 4 springs to assembled Frontcover Workstation Screwing 10 Laser Engraving Figure 1-6: Current Assembly Process in the Factory 11 Vietnamese-German University 1.3 Work and Time Study Discussions and conclusions The data were collected by numerous persons and therefore its quality may varied. However, we found some consistent trends between measurements of different groups. Most data have high relative confidence level, between 10% and 20%. Nonetheless, workers who do single jobs have more stable working trend, with lower confidence level, for example adding springs to locking block (11.7%), soldering (7.1%) and (4.3%) or laser marking (6.3%), while sophisticated works require more varied time. The relative confidence level of some tasks are significantly high, including adding locking block (16%), slider (15 - 18%), or balancing the shaft on the front cover (16 - 18%), suggesting that those tasks are more tricky. The workshop temperature is fairly high, which can significantly affect productivity and stress out the workers. It is also unevenly lighted. The brightness of work stations was far less than national standard of lighting requirement for electronic assembly workshops, which is 750 lux [TCV-2008]. One should be cautious that this measurement method may be significantly inaccurate, however, there is noticeable different lighting condition between two lines. More specifically, there are 2 neon tubes in each work station in main line (work stations 7, 8, 9, 10), whereas the work stations in the subordinate line are only lighted by ceiling lights. Generally, most workers their jobs at ease, although some more they find some difficulties with smaller parts such as springs and sprockets. The springs are especially tricky because they tends to stuck together and takes time to be untangled. In both lines, there is a redundant task in which the middle worker has to transfer an element from one adjacent colleague to another. The worker 8 has to transfer the frontcover from worker 7 to worker 9 and the assembly box the reverse way. Worker 2 also has to transfer locking blocks from worker 1 to worker 3 after the first one finish a few dozens of them. She might find it difficult to collect a handful of tiny elements and possibly drop some during conveyance. The workers in two lines use different tools and do some minor different steps. This can lead to unbalanced quality and time goal. One worker is equipped with the manual screwdriver and the other electric one, and this leads to three times difference in execution time (46.6 seconds vs 17.6 seconds per work piece). The latter also check all the buttons after finishing one piece and repair it instantly if there is a defect. One significant trend is that workers in main line are faster than those on the subordinate line. Worker 8 took 29 seconds to finish a shaft, while the time for worker 3 is 47.4 seconds. Worker 9 took only 20.8 seconds to add 4 springs and put the shaft on frontcover, while the other took 33.3 seconds. That is around 50% more quickly of workers 8 and 9, in compare with their colleagues. 12 Vietnamese-German University Work and Time Study There’s no major different between worker 7 and 4 in time from put the housing to add battery holder. However the former’s time is longer because she has to remove the frontcover from a plastic bag, and check its quality. We have observed many occasions when workers had to wait for elements supply. Worker 1 waited for material 23% of her time, where worker 6 and 9 did 21.7% and 20% respectively. Worker 5 spent more than half of her time for transportation motors into a storage box, or set up the motors onto a holding tray, which are non value-added activities. Worker 10 took two-thirds of her time waiting either for the machine or the next product to come. This suggest that the work flow is interrupted. We calculated the average processing time of the two lines, by taking the mean processing time of the workers that do the same tasks. (i.e., workers 2 and 9, 3 and 8, 4 and 7). We incorporated quality checking steps from main line, and screwing time of the worker with electronic screwdriver (work station 9). The highest execution time is found in final assembly station, with 51.7 seconds, and this time is the decisive speed of the work flow (tact time) 1.4 Conclusion After collecting those data, we concluded that the working condition for the workers should be improved. We also suggest an optimization for the process, in which the tasks are shared more evenly between workers, and some other adjustments to improve productivity 2 Optimization 2.1 2.1.1 Method Identify current Problems According to observation in the electronic door lock assembly line, there are 8 workstations by the overview and each workstation are operating the process with some inefficient workflow such as waiting time, transportation time and unbalance activities. It can be seen from the data in Figure 1-4, the inadequate positions make workers waste time on getting, searching and transferring material. Moreover, the executing time of screwing is very high, at 51 seconds per one workpiece; and while the executing time it makes the worker who use the laser machine to engrave numbers into locks has to wait for the material. And the waiting time for other activities is also high. This is the interruption due to dysfunction, lack of material. 2.1.2 Approach and Optimization Process After doing stopwatch time study in each assembling line, we clarify the working process partly based on current process, layout. We divide the whole assembly line into three parts: Preassembly, Main-Assembly, and Testingre-Assembling: comprise soldering processes whose cycle time are small. The worker can operate continuously and efficiently without releasing soldering torch. 13 Vietnamese-German University - - Work and Time Study Main-Assembling: comprise processes related to front-cover and shaft assembling. These processes have many small related steps without unable to separate, so they required a high activity time. Testing & Packaging: In this process, the product will be tested by machine and inspected visually before packaging. 2.1.2.1 Pre-Assembly Line Pre-Assembly Line includes three sub-process: Wire-Motor Soldering Process, Board-Motor Soldering Process, Spring-Board Soldering Process. This stage can be seen as the material preparation for Main Assembly Line. It would be more efficient if the worker only solders boardwire-motor continuously and there is no waiting time. The number of output workpieces is big enough for Main assembly line Pre Assembly t (s) 15 Wire Motor Wire-Motor Soldering Wire-Motor Small Board t (s) t (s) 23 22 Board-Wire-Motor Soldering Big board 2 Springs Spring-Big board Soldering Figure 2-1: Pre-assembly Process The executing time (te) of soldering process includes the soldering time (tMA) and the personal allowance time (tP) te = tMA + tP [HEL-2016] The executing time of Wire-Motor Soldering: te1 = 15s The executing time of Small Board-Wire-Motor Soldering: te2 = 23s The executing time of Spring-big Board Soldering: te3 = 22s To increase efficiency, assigning two workers who are responsible for soldering Small circuit board – Wire – Motor at workstation 1 and 2; one worker for soldering 2-springs-to-big board at workstation 3. Because of relatively small processes time, the workers solder components quickly and repeatedly without releasing solder torch. The number of output workpieces is sufficient high for ensuring operation in Main Assembly line. 2.1.2.2 Main Assembly Line Main Assembly Line comprises four sub-processes: Front-Cover Assembling Process, Shaft Assembling Process, Screwing Process, Laser Engraving Process. The output from Pre-Assembly line is delivered to Front-cover Assembling process and Shaft Assembling process. According to process 14 Vietnamese-German University Work and Time Study time at Measurement in Appendix 4, we detach the possible elements which take big time. Main assembly line is rearranged and optimized as below: - Workstation 4 combines Locking-Block Assembling Process with Shaft Assembling Process. In this process, worker assemble The process time for one workpiece is the total time of executing time of shaft assembling and locking-block assembling. The process time at Workstation 4: te4 = 41 + 13 = 54 (s) - Workstation 5 combines Front-cover Assembling Process and Putting 4 springs-to-assembled front-cover Process. The executing time for one workpiece is the total time of frontcover assembling time and time of putting four spring. The process time at Workstation 5: te5 = 44 + 20 = 64 (s) - Workstation 6 screws the assembled shaft into assembled Front cover. Since this process is no longer including the step of put 4 springs-to-assembled Front-cover to workstation 4, the Pre Assembly Big Board – Spring Soldering 1 3 2 Wire – Motor Soldering Small board – Motor Soldering Main Assembly 5 5 Frontcover Assembling 4 4 13 sec Put spring to locking block 44 sec 20 sec Put 4 springs to assembled Frontcover 6 31 sec 7 31 sec 8 Shaft Assembling 42 sec Screwing Laser Engraving Workstation Testing & Packaging process time at Workstation 6 is decreased, it is: Figure 2-2: Main Assembly process te6 = 31 (s) - Workstation 7 is for laser engraving process; its process time cannot be reduced because the limit of capacity of laser machine. the process time at Workstation 6: te7 = 31 (s) Because of high process time, assigning two workers for each workstation 4 and 5 to decrease a half of the process time for one workpiece assembling. 2.1.3 Optimized Process and New Layout After rearranging and optimizing activities among workstations for balancing process time and reducing waiting time. We have a detail optimized process as figure 3-3. 15 Vietnamese-German University Work and Time Study Pre Assembly t (s) Wire 15 Motor Wire-Motor Small Board t (s) t (s) 23 22 Board-Wire-Motor Soldering Wire-Motor Soldering Big board 2 Springs Spring-Big board Soldering Main Assembly t (s) 13 Add spring to locking block Add locking block Check quality Add Add Motor Greas Fold Slider & Sprocket e board Add buttons 41 Add 4 small Springs Add preassembled shaft Fix 4 screws Check button Add t (s) battery holder 44 Wait for proceeding Laser Engraving t (s) 20 t (s) 31 Screwing Put in laser marking machine Add big board Frontcover Assembling t (s) Shaft Assembling Add support grid Take out and end t (s) process 31 Testing & Packaging Testing Packaging Figure 2-3: Optimized process Based on current workspace, facilities and manpower (10 persons), we change some workstation for improving efficient of the material flow as figure 3-4. The figure explains the process for the making of a complete product. There is a total of 8 stages with ten workers in the process, beginning with the soldering wire-motor-board and culminating in the production of the electronic door lock. To begin, the two wire is soldered to a motor at workstation 1 and then delivered to workstation 2 for soldering to a small board. At workstation 3, a worker solders two springs into a big board. 16 Vietnamese-German University Work and Time Study This process is a material preparation for Main assembly line. The output of workstation 2 is transferred to workstation 4 for adding sprocket, sliders, locking block, grease and assembling into a shaft, while the workers at workstation 5 receive the workpiece from workstation 3 and assemble with front-cover. Next, the workpiece output from workstation 4 and 5 is gathered at workstation 6 for screwing. Two workers are assigned for each workstation 4 and 5 to ensure that one assembled shaft and one assembled front-cover are delivered to screwing workstation every 32 seconds. Eventually, the workpiece output of workstation 6 is engraved by laser machine at workstation 7 before tested by a worker at workstation 8. As the result, one product is finished in every 32 seconds. Work Piece OUTPUT Pre-Assembly 1 2 3 Wire-Motor Soldering Small BoardMotor Soldering Big BoardSpring Soldering t = 23s t = 15s t = 22s t = 64s Main-Assembly 5 t = 54s t = 64s Front Plate Assembling Tranfer Shaft Assembling 5 4 Work Piece INPUT 8 7 6 Testing & Packaging Laser Engraving Screwing Shaft Assembling t = 31s t = 54s t = 31s 4 Figure 2-4: New Layout for optimized process 17 Vietnamese-German University Work and Time Study Result 2.2 2.2.1 Line Balancing After reviewing the collected data from stopwatch time study, we balanced the whole process flow by adding workforce, changing process flow and delegating process activities. This balancing can powerfully optimize the current process regarding waste elimination and optimal cycle times of each workstation. Table 2-1: Comparison Between Current Condition and Improved Condition Current Condition Workstation Front-cover Assembling workstation Shaft Assembling workstation Screwing Assembling workstation Laser Engraving workstation 2.2.2 Time per cycle After Line Balancing Waiting time Share of waiting time Man power 32 0 0% 2 1 27 5 18% 2 0% 1 31 1 3% 1 68% 1 31 1 3% 1 Waiting time Share of waiting time Man power Time per cycle 45 7 16% 1 41 11 27% 52 0 31 21 Develop New Standard Time and Workstation Optimized tact time and leveled production line were developed as a result of optimization after organizing the process flow and sequences concerning workforce, layout, worker activities and cycle time. And then, also waiting times are reasonably minimized and generated optimal efficient and productive flow. 18 Vietnamese-German University Work and Time Study 40 32 35 Time (s) 31 31 Screwing Laser Engraving 28 30 25 20 15 10 5 0 Frontcover Assembling Shaft Assembling Table 2-2: Main Assembling Process for one Product 2.2.3 Productivity: According to our team observation, we set up the tact time base on the Front-Cover Assembly Process (longest time workstation) that take 32 seconds to produce a workpiece. Productivity Calculation is carried out by company available working hour per day which is consider by personal and factual allowance time. Table 2-3: Productivity of Assembly Line Before and After Optimization Particular Working time per day 2.3 2.3.1 Productivity Before Optimization 28800 sec Productivity After Optimization 28800 sec Activity time per day 25920 sec 25920 sec Tact time Waiting time per day 52 sec 23% 32 sec 5,78% Output Quantity per day 498 products 810 products Discussion Explanation for result Relationship Between Front-cover Assembling & Screwing The total time for making one piece of Assembled Front-cover by one worker is about 64 seconds. Moreover, next workstation, Screwing Process only take 31 seconds per worker for finished one product. So, every 31 seconds, screwing worker can finish one product. However, if using only one worker in Front-cover Assembling workstation, the Screwing workstation will have to wait for 33 seconds and impossible to make final product continuously. The only way to eliminate its waiting time is adding one more worker in Front-cover Assembling Workstation and one workpiece will 19 Vietnamese-German University Work and Time Study be finished and delivered to Screwing workstation in every 32 seconds. It will be minimized waiting time for Screwing workstation. Relationship Between Shaft Assembling & Screwing The total time for making 1 piece of Assembled Shaft by one worker is about 54 seconds. The cycle time of next workstation Screwing is only 31 seconds per worker. So, every 31 seconds it will produce one finished workpiece. However, if assigning only one worker in the previous workstation, the Screwing workstation will have to wait for 23 seconds and impossible to make workpiece continuously. That is why the Shaft Assembling work station need to use 2 workers and then 2 workpieces should be finished by 56 seconds, 27 seconds for one workpiece respectively. Thus, there is no more waiting time for each workstation. Relationship Between Screwing & Laser Engraving Machine Laser Engraving Process is the final work station of Electronic Lock Assembling line. It takes 31 seconds to engraving on product buttons; that means the machine can produce 1 engraved product for every 31 seconds. In this case, Screwing Workstation can supply the product to Laser Engraving Workstation on time because it can convey its product by every 31 seconds. There is no more waiting time for each product as well. 2.3.2 Improvement and Advantages & practicability (viability) Advantage: Process Optimization based on line balancing is very easy to apply and less operation cost. The Calculation base on practical measurements from stopwatch time study can provide benefits in flexibility for any improvements and modifications. Besides, the reduction of unnecessary motions and transportation can create a comfortable workplace for workers. Result in the systematic & optimized workflow, waste elimination and speed up productivity. Limitation: - - 2.4 The optimization is studied for ten workers with, one laser machine, one screwing machine. Thus, there are some limits about facilities, manpower, and workspace such as limited table, workers, speed of machine and quantity of machine. The cycle time of one laser engraving machine cannot be flexible for any raising of product demand. Many simulations are required to ensure new process flow and layout can meet the standard cycle. The accuracy of time and activity totally depends on the performance rate of workers and need providing training & performance assessment. Conclusion The primary purpose of our report that we executed together with our team is to develop more efficient process optimization in Electronic Lock Assembling Line of Fisher Co., Ltd. 20