英文IE知识课件.pptx
Industrial Engineering:Work DesignPrepared by Ken Leung2002/9/261SMT Training for ProductivityWork DesignnMethods ImprovementnErgonomicsnAssembly line balancingnPrinciples of motion economynVarious type of chartsnWork measurementnTime studynActivity sampling2002/9/262SMT Training for ProductivityErgonomics nDefinitionnApply information about human behavior,abilities,limitations,and other characteristics to the design of tools,machines,system,tasks,jobs,and environments for productive,safe,comfortable,and effective human use.2002/9/263SMT Training for ProductivityObjectives nTo enhance the work effectiveness and efficiency.nIncreased convenience of use nReduced errors nIncreased productivity nTo enhance human values.nImproved safetynReduced fatigue and stressnIncreased comfortnGreater user acceptancenIncreased job satisfaction nImproved quality of life2002/9/264SMT Training for ProductivityTwelve Principles of Ergonomics1.Work in neutral posturesneg.Wrist rests for keyboard and mouse.2.Reduce excessive forces-eg.Boxes with handholds for carrying.2002/9/265SMT Training for ProductivityErgonomics Principles3.Keep everything in easy reach-eg.Keep materials within the“reach envelope”of the arm.2002/9/266SMT Training for ProductivityErgonomics Principles4.Work at proper heights-eg.Heavy work should be performed lower than elbow height;precision work should be higher.2002/9/267SMT Training for ProductivityErgonomics Principles5.Reduce excessive motions neg.Use power screwdriver.6.Minimize static load-eg.Use a pencil grip.2002/9/268SMT Training for ProductivityErgonomics Principles7.Minimize pressure points neg.Provide padding for hand grips.8.Provide clearance-eg.Provide visual access (carton delivery).2002/9/269SMT Training for ProductivityErgonomics Principles9.Move,exercise,and stretch-eg.Change adjustments of the chair for those sit for a long time.10.Maintain a comfortable environment-eg.Consider the quantity and quality of light at the workstation.2002/9/2610SMT Training for ProductivityErgonomics Principles11.Make displays and controls understandable neg.Clicking is easier than memorizing commands.12.Reduce stress-eg.Design task to fit people.2002/9/2611SMT Training for ProductivityAnthropometry nDefinitionnMeasurement of the human body and its biomechanical characteristics.nBiomechanical refers to the mechanical(machine-like)capabilities of the human skeleton-muscular systems.nMeasures our sizes and how we move and move easily.nNeed of AnthropometrynWe are not in the same size.nPoor design for mechanical abilities of the human body can lead to discomfort or injury.nEg.Height of keyboard for a computer.2002/9/2612SMT Training for ProductivityAnthropometric DatanStatic measures are used to determine size and spacing requirements of work space,eg.,height,weight,seat to elbow height,and wing span.nDynamic measures are used to match the dynamic characteristics of controls to user,eg.,range of motion for various joints,and strength of fingers.2002/9/2613SMT Training for ProductivityAnthropometric DatanThe anthropometric data is performed in normal distribution.n50th percentile is the most of the population.n5th and 95th percentiles are the extremes.2002/9/2614SMT Training for ProductivityHow to use anthropometric datanDesign for extremesnA standard is to design to fit 5th or 95th percentiles of the population.nDesign for most of the populationn50th percentile of the population should be used.nMake the design adjustable nThe design can fit 5th to 95th percentiles of the population.2002/9/2615SMT Training for ProductivityExamples Design aimsDesign examples:Examples of measurements to consider:Users that the design should accommodate:Easy reach Shelving Arm length,shoulder heightSmallest user:5th percentileAdequate clearance to avoid unwanted contact or trapping Cinema seats Shoulder or hip width,thigh lengthLargest user:95th percentileA comfortable and safe posture Worksurface heights Elbow height,sitting eye height,elbow height(sitting or standing)Most of the users:50th percentileSpecial fitting Headphones Head circumferenceMaximum range:5th to 95th percentile(adjustable design)2002/9/2616SMT Training for ProductivityAssembly Line BalancingnEqualize workload among the assemblies.nIdentify the bottleneck operation.nEstablish the speed of the assembly line.nDetermine the number of work stations.nDetermine the labor cost of assembly.nEstablish the percent workload of each operator.nAssist in plant layout.nReduce production cost.2002/9/2617SMT Training for ProductivityTable for Assembly Line BalancingNo.Operation R-ValueCycle time#stationsAvg.cycle time%LoadHrs/1000Pcs./hrA1Sub-assembly 0.2160.2110.211003.5285A2Assembly 0.2160.44130.1477010.595 Major items:operation description,R-value,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.12345672002/9/2618SMT Training for ProductivityItems for Assembly Line Balancing TableR-value(plant rate):nTakt time or time needed to produce a product.n=effective production time/required production volume.Cycle time:nStandard time for operation.nCollected from time study.#stations:-=Cycle time/R-valueAverage cycle time:n=Cycle time/#stations 12342002/9/2619SMT Training for ProductivityItems for Assembly Line Balancing Table%Load:-Tell how busy each work station is compared 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 sub-assembled or combined.52002/9/2620SMT Training for ProductivityItems for Assembly Line Balancing TableHours/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 1000672002/9/2621SMT Training for ProductivityImprove Assembly Line BalancingnCalculate the Line Balance ratenReducing the bottleneck station.nCombining the bottleneck station with an operation in front or behind.nCombining other operations to eliminate one of them.2002/9/2622SMT Training for ProductivityExample:Original Line BalanceNo.Operation R-Value(mins)Cycle time(mins)#stationsAvg.cycle time(mins)%LoadHrs/1000Pcs./hr1Place bottom housing on line and lubricate0.250.20010.200804.172402Assemble parts 3,4,&50.250.25010.2501004.172403Assemble parts 6&7 together and place sub-assembly in housing0.250.30520.153618.341204Drive 6 bolts holding sub-assembly in bottom housing0.250.60030.2008012.50805Get vent cover&cement in place assembly to bottom housing0.250.19810.198794.172406Get top housing,apply cement&assemble to bottom housing0.250.29020.145588.341207Place in carton&in master carton(6 per)and aside to pallet0.250.62530.2088312.5080Total 131.354n Producing new plastic charger;1200 units per 8-hrs shift(with 300 mins effective).2002/9/2623SMT Training for ProductivityExample:Original Line BalancenOriginal line balance rate=total cycle time/highest cycle time station x no.of stations=1.354/(0.25 x 7)=77.4%nPcs./hr=60/0.25=240nImprove the bottleneck station by combining with an operation in front or behind.nCombine and eliminate work steps.nRe-design the jig&fixture.OperationsBottleneck or 100%load station2002/9/2624SMT Training for ProductivityExample:Improved Line BalanceNo.Operation R-Value(mins)Cycle time(mins)#stationsAvg.cycle time(mins)%LoadHrs/1000Pcs./hr1&2Place bottom housing on line,lubricate,&assemble parts 3,4,&5.0.250.45020.225987.631313&4Assemble parts 6&7 together.Place in housing&drive 6 bolts holding sub-assembly to housing.0.250.90540.2269915.26655Get vent cover&cement in place in bottom housing.0.250.19810.198863.822626&7Get top housing,apply cement&assemble to bottom housing,pack out.0.250.91540.22910015.2665Total 110.878n Improved line balance 2002/9/2625SMT Training for ProductivityExample:Improved Line BalancenImproved line balance rate=total cycle time/highest cycle time station x no.of stations=0.878/(0.229 x 4)=95.9%nPcs/hr=60/0.229=262nIncrease in output with decrease in no.of workstations.OperationsBottleneck or 100%load station2002/9/2626SMT Training for ProductivityPrinciples of Motion EconomynGuidelines for efficient and effective work station design.nSummarized to 4 major elements:nElimination nCombination nRearrangementnSimplification2002/9/2627SMT Training for ProductivityElimination nEliminate all possible jobs,steps,or motions.nEliminate irregularities in job.nEliminate the use of hand as holding device.nEliminate abnormal motions.nEliminate the use of muscles to maintain a fixed position.nEliminate muscular force by using power tools.nEliminate danger.nEliminate idle time.2002/9/2628SMT Training for ProductivityCombination nReplace with one continuous short motion.nCombine tools,controls,and motions.RearrangementnDistribute the work evenly between two hands.nShift work from the hands to the eyes.nArrange for a straight forward order of work.2002/9/2629SMT Training for ProductivitySimplification nReduce eye travel.nKeep work in the normal work area.nShorten motions.nAdapt handles,levers,pedals,buttons,etc.,to human dimensions and musculatures.2002/9/2630SMT Training for ProductivityApplying the Principles of Motion Economy1.Move both arms in unison or move them symmetrically,but do not move just one arm at a time.Eg.Take the cap off an ink bottle.2002/9/2631SMT Training for ProductivityApplying the Principles of Motion Economy2.To minimize body movement by limiting movements to body parts with low time rankings.The following illustration shows the correlation between arm movement and working time.2002/9/2632SMT Training for ProductivityApplying the Principles of Motion Economy3.Minimize fatigue by repeating motions with a natural feeling of rhythm and by making your curved movements as smooth as possible.Do as little holding or adjusting of materials as you can.Use stands or jigs to hold your materials or tools for you.2002/9/2633SMT Training for ProductivityApplying the Principles of Motion Economy4.Keep materials and tools in specified places in front of and around you.5.Try to keep from fighting gravity with the materials you are handling;move them down,not up.Eg.Use a chute to transport the products by its own gravity.2002/9/2634SMT Training for ProductivityApplying the Principles of Motion Economy6.Try to set your chair or desk at the most comfortable position and make sure your lighting is bright enough and at a good angle.7.If you utilize your legs and feet,you can lighten the load on your arms and hands.2002/9/2635SMT Training for ProductivityApplying the Principles of Motion Economy8.Side-to-side eye movements are less tiring than up-and-down ones.9.Whenever possible,combine procedures,using your tools as extensions of your hands and feet.Try to combine two or more tools into one.2002/9/2636SMT Training for ProductivityVarious types of chartsnUsed as record techniquesnOutline process charts:nOverview of a process with graphical representation.nShow principal operations()and inspections().nAssist in the plant layout design,design of product,or machinery processes.2002/9/2637SMT Training for ProductivityVarious types of chartsnFlow process chart:nActivities of men,material or equipment.nTwo or more subjects can be presented alongside each other to show their interdependence.nActivities are divided by 5 functions,operation(),transport(),storage(),delay(D),inspection().nOnly the activities of particular subject,either man,material,or equipment,are recorded on a single chart.2002/9/2638SMT Training for ProductivitynExample,Flow process chart:Inspecting and markingincoming parts(original method)2002/9/2639SMT Training for ProductivitynExample,Flow process chart:Inspecting and markingincoming parts(improved method)2002/9/2640SMT Training for ProductivityVarious types of chartsnTow-handed process chart:nUseful in showing idle time by either hand.nActivities of a workers two hands.nSimultaneous movements by both hands appear opposite each other.nDescription of the activities represented by the symbols should be inserted.2002/9/2641SMT Training for ProductivitynExample,Two-handed process chart:Cutting glass tubes(original method)2002/9/2642SMT Training for ProductivitynExample,Two-handed process chart:Cutting glass tubes(improved method)2002/9/2643SMT Training for ProductivityVarious types of chartsnMultiple activity charts:nConsider on the activities of a subject in relation to one or more others.nShow up clearly ineffective time within the process.nUseful in finding the best sequence of carrying out the various parts of the work.nOperation/machine chart shows the interrelationship of the operator and the machine.2002/9/2644SMT Training for ProductivitynExample,Multiple activity chart worker and machine:Finish mill casting(original method)2002/9/2645SMT Training for ProductivitynExample,Multiple activity chart worker and machine:Finish mill casting(improved method)2002/9/2646SMT Training for ProductivityTime StudynMost common technique for setting time standards.nUseful for repetitive work.nProvide standard rate of working.nA means of assessing the amount of rest that should be associated with the job.2002/9/2647SMT Training for ProductivityTime Study:Procedures1.Select the job to study.2.Collect information about the job.3.Divide the job into elements.4.Do the actual time study.5.Extend the time study.6.Determine the number of cycles to be timed.7.Rate,level,and normalize the operators performance.8.Apply allowances.9.Check logic.10.Publish the time standard.2002/9/2648SMT Training for ProductivityTime Study:Focus PointsnExtend the time studynCalculate average observed time.nDetermine performance rating.nCalculate normal time:-Normal Time=average observed time x performance rating nFind out frequency(how many times a task is performed within a time period).nCalculate unit normal time.2002/9/2649SMT Training for ProductivityTime Study:Focus PointsnDetermine the number of cyclesnN=number of cycles nR=range of the sample of observations(in minutes)nA=required precision(+/-5%or 10%)nd2=statistical constant(3.078 for 95%confidence level)nx=average time(in minutes)2002/9/2650SMT Training for ProductivityTime Study:Focus PointsnPerformance ratingnRating is the process of adjusting the time taken by an individual operator to what could be expected from a normal operator.nFour major factors:skill,consistency,working conditions,and effort.nEffort is the most important.nEffort is the operators speed,and is measured based on the normal operator working at 100%.2002/9/2651SMT Training for ProductivityTime Study:Focus PointsnRelaxation allowancenIt is the allowance for the periodic stops for personal needs or fatigue.nExample
