【正文】 13 SMT Training for Productivity Anthropometric Data ? The anthropometric data is performed in normal distribution. ? 50th percentile is the most of the population. ? 5th and 95th percentiles are the extremes. 2023/9/26 14 SMT Training for Productivity How to use anthropometric data ? Design for extremes ? A standard is to design to fit 5th or 95th percentiles of the population. ? Design for most of the population ? 50th percentile of the population should be used. ? Make the design adjustable ? The design can fit 5th to 95th percentiles of the population. 2023/9/26 15 SMT Training for Productivity Examples Design aims Design examples: Examples of measurements to consider: Users that the design should acmodate: Easy reach Shelving Arm length, shoulder height Smallest user: 5th percentile Adequate clearance to avoid unwanted contact or trapping Cinema seats Shoulder or hip width, thigh length Largest user: 95th percentile A fortable and safe posture Worksurface heights Elbow height, sitting eye height, elbow height (sitting or standing) Most of the users: 50th percentile Special fitting Headphones Head circumference Maximum range: 5th to 95th percentile (adjustable design) 2023/9/26 16 SMT Training for Productivity Assembly Line Balancing ? Equalize workload among the assemblies. ? Identify the bottleneck operation. ? Establish the speed of the assembly line. ? Determine the number of work stations. ? Determine the labor cost of assembly. ? Establish the percent workload of each operator. ? Assist in plant layout. ? Reduce production cost. 2023/9/26 17 SMT Training for Productivity Table for Assembly Line Balancing No. Operation RValue Cycle time stations Avg. cycle time % Load Hrs / 1000 Pcs. / hr A1 Subassembly 1 100 285 A2 Assembly 3 70 95 ? Major items: operation description, Rvalue, cycle time, number of stations, average cycle time, percent load, hours per 1000 pieces, and number of pieces per hour. ? An example is as follows. 1 2 3 4 5 6 7 2023/9/26 18 SMT Training for Productivity Items for Assembly Line Balancing Table Rvalue (plant rate): n Takt time or time needed to produce a product. n = effective production time / required production volume. Cycle time: n Standard time for operation. n Collected from time study. stations: = Cycle time / Rvalue Average cycle time: n = Cycle time / stations 1 2 3 4 2023/9/26 19 SMT Training for Productivity Items for Assembly Line Balancing Table % Load: Tell how busy each work station is pared to the busiest work station. % Load = Avg. cycle time / highest avg. cycle time. Highest avg. cycle time (100% station) is the bottleneck. 100% station is reduced by 1%, then we will save 1% for all stations. The less percent loaded, the more desirable to be subassembled or bined. 5 2023/9/26 20 SMT Training for Productivity Items for Assembly Line Balancing Table Hours / 1000 : The hours per 1000 units produced. Choose the bottleneck station. = (Avg. cycle time / 60 mins) x 1000 For more than one workers at the station, “hrs/1000” = workers x “hrs/1000” of bottleneck. Because everyone on an assembly line must work at the same rate. Pcs. / hr : Number of units produced hourly by one worker at the station. = 1 / “Hrs/1000” X 1000 6 7 2023/9/26 21 SMT Training for Productivity Improve Assembly Line Balancing ? Calculate the Line Balance rate ? Reducing the bottleneck station. ? Combining the bottleneck station with an operation in front or behind. ? Combining other operations to eliminate one of them. 2023/9/26 22 SMT Training for Productivity Example: Original Line Balance No. Operation RValue (mins) Cycle time (mins) stations Avg. cycle time (mins) % Load Hrs / 1000 Pcs. / hr 1 Place bottom housing on line and lubricate 1 80 240 2 Assemble parts 3, 4, 5 1 100 240 3 Assemble parts 6 7 together and place subassembly in housing 2 61 120 4 Drive 6 bolts holding subassembly in bottom housing 3 80 80