液压缸生产计划与控制.docx

液压缸生产计划的制定目录一、 市场需求预测-2二、 实际产品的生产工艺路线分析-6三、 生产方式的经济分析和比较-8四、 制定综合生产计划-13五、 生产能力的粗平衡-13六、 制定主生产计划-14七、 制定MRP,CRP-15八、 生产能力的精平衡-22九、 零件工序卡编制-22十、 产品装配工序卡编制-24一 .市场需求预测（Market forecast）历史数据已知如下：Historical Record (Aggregate Demand)Quarter 1Quarter 2Quarter 3Quarter 4Year110192522Year211212824Year312223026Year41.观察历史数据，判断市场需求与时间季节因素有关。下面采取两种方案，分别用POM软件进行预测，比较结果，选取适合的方案。方案（1）:SEASONALIZED TIME SERIES REGRESSION FORECASTING采用POM软件进行预测，结果如下：* SEASONALIZED TIME SERIES REGRESSION FORECASTING *-PROBLEM NAME: SEASONALIZED TIME SERIES REGRESSION FORECASTING- FORECAST Sales - ABSOLUTE YEAR SEASON ACTUAL REGRESSION SEASONALIZED ERROR 1 1 10.000 18.672 9.859 0.141 1 2 19.000 19.065 18.912 0.088 1 3 25.000 19.458 25.840 0.840 1 4 22.000 19.851 22.868 0.868 2 1 11.000 20.244 10.689 0.311 2 2 21.000 20.637 20.472 0.528 2 3 28.000 21.030 27.928 0.072 2 4 24.000 21.423 24.679 0.679 3 1 12.000 21.816 11.519 0.481 3 2 22.000 22.209 22.031 0.031 3 3 30.000 22.602 30.015 0.015 3 4 26.000 22.995 26.490 0.490- Sales CONFIDENCE INTERVAL ( 99%) YEAR SEASON FORECAST LOWER BOUND UPPER BOUND 4 1 12.349 11.426 13.272 4 2 23.591 21.857 25.324 4 3 32.103 29.782 34.424 4 4 28.301 26.287 30.314REGRESSION EQUATION: Y = a + bX WHERE: Y = Sales X = TIME PERIOD a = 18.2789 b = 0.3930FORECAST = Y * SEASONAL INDEX (i)R = 0.938R-SQUARE = 0.8789MEAN ABSOLUTE DEVIATION (MAD) FOR THE LAST 3 PERIODS = 0.179MEAN SQUARED ERROR (MSE) FOR ALL PAST PERIODS = 0.234MEAN ERROR (bias) FOR ALL PAST PERIODS = -0.108STANDARD ERROR (sigmasubyx) IS = 0.5515SEASONAL INDEX (1) = 0.528SEASONAL INDEX (2) = 0.992SEASONAL INDEX (3) = 1.328SEASONAL INDEX (4) = 1.152方案（2）:TIME SERIES REGRESSION FORECASTING采用POM软件进行预测，结果如下： * TIME SERIES REGRESSION FORECASTING *-PROBLEM NAME: TIME SERIES REGRESSION FORECASTING- Sales Sales ABSOLUTE PERIOD ACTUAL FORECAST ERROR 1 10.000 16.026 6.026 2 19.000 16.900 2.100 3 25.000 17.774 7.226 4 22.000 18.648 3.352 5 11.000 19.522 8.522 6 21.000 20.396 0.604 7 28.000 21.270 6.730 8 24.000 22.145 1.855 9 12.000 23.019 11.019 10 22.000 23.893 1.893 11 30.000 24.767 5.233 12 26.000 25.641 0.359- Sales CONFIDENCE INTERVAL ( 99%) PERIOD FORECAST LOWER BOUND UPPER BOUND 13 26.515 7.021 46.009 14 27.389 7.895 46.883 15 28.263 8.770 47.757 16 29.138 9.644 48.631REGRESSION EQUATION: Y = a + bX WHERE: Y = Sales X = TIME PERIOD a = 15.1515 b = 0.8741R = 0.473R-SQUARE = 0.2241MEAN ABSOLUTE DEVIATION (MAD) FOR THE LAST 3 PERIODS = 2.495MEAN SQUARED ERROR (MSE) FOR ALL PAST PERIODS = 31.533MEAN ERROR (bias) FOR ALL PAST PERIODS = 0.0STANDARD ERROR (sigmasubyx) IS = 6.15142.分析: a.对方案(1)和方案(2)预测结果进行比较，方案(1)相关系数为0.938，方案（2）相关系数为0.473，从相关性上来说，方案(1)比方案(2)好.b.方案（1）绝对系数为0.8789，则方案(1)有87.89%与预测相关，方案(2)绝对系数为0.2241，则方案(2)有22.41%与预测相关，故方案（1）比方案（2）更准确c.方案(1)标准差为0.5515，方案(2)标准差为6.1514，大于方案(1)标准差。综合考虑以上采用方案(1)预测更为准确。3.对方案（1）预测结果取整，得到最终预测结果为：Quarter1234FORECAST years413243329二实际产品的生产工艺路线分析(Product Process Analysis)总件与零件名称数量如下表所示：组件零件级别名称需求数量提前期YYG0液压缸10YYGHSG1活塞杆12GT-11缸筒12GT-21缸头12GD1缸底12FL1法兰22EH1耳环12ZJZ1中铰轴12各零件加工工艺过程如下表所示：代号名称数量零件工艺过程Lead Time（周）12345678910HSG活塞杆1圆钢下料粗车（外圆）调质校直半精车（杆）铣/钻扳手位镀前磨电镀镀后磨精车（杆）抛光2GT-1缸筒1管料下料粗车（外圆）粗镗（筒）精镗（筒）滚压（筒）精车（筒端螺纹）2GT-2缸头1圆钢下料粗车（零）精车（零）-精铣（零）划线-钻2GD缸底1圆钢下料粗车（零）精车（零）精铣（零）划线-钻2FL法兰2圆钢下料粗车（零）精铣（零）精车（零）划线-钻2EH耳环1锻件下料粗车（零）铣外形镗孔钳工钻孔2ZJZ中铰轴1锻件下料粗车（零）铣外形镗孔精车2三生产方式的经济分析与比较(Alternative Plans Comparison)已知条件如下：StandardCapacityLabor Standard600(Labor-Hour/Assemble)Wokers work hoursStraight-Time8hours/day*25 days/monthOver-TimeMaximum 20% Straight-TimeBeginning Worker Employed90Machine Standard450(Machine-Hour/Assemble)Machine Capacity13050(Hours/Month)Assemble Standard150(Assemble-Hour/Assemble)Assemble Capacity4200(Hours/Month)Straight-Time Pay2.2($/Hour)Inventory Carry Cost80($/Month)Over-Time Pay2.6($/Hour)Hire Cost10($/Worker)Subcontract Price2200($/Assemble)Lay Off Cost60($/Worker)1.计算每季度最大生产值Machine capacity=13050/450=29(assemble/month)Assemble capacity=4200/150=28(assemble/month)所以每季度最多生产28台。2.比较分析均衡生产与市场匹配的经济性平均每季度的需求为：Q=（13+24+33+29）/4=24.75 ，取25整。由于初始库存是10，安全库存是6个，若按均衡式生产，最多可挪用4个使用，则每季度生产24个。首先，列表比较两种生产需要雇佣/解雇的工人数以及每年的库存。经计算后列表如下:1234567Aggregate planMonthAggregate demandPlanned outputsWorkers requiredWorkers hiredWorkers laid offLevel capacity with inventory1132472018224247200333247200429247200Matching demand11313390512242472330333288412042928840089101112Inventory adding Beginning inventoryEnding inventoryAverage inventory per quarterAverage inventory per month11102115.5 15.6250212121(9)211216.5(5)1279.500000000000000000再列表比较两种方式生产所花费的成本。计算列表如下：（1）（2）（3）（4）（5）（6）Aggregate planTotal annual number of workers hiredTotal annual number of workers laid offAverage Month inventory Annual hiring and layoff costAnnual inventory carrying costTotal annual incremental operating costLevel capacity01815.625108050006080Matching demand4551003510备注：（4）=（1）*10+（2）*60；（5）=（3）*4*80：（6）=（4）+（5）由于在matching demand生产计划中第三月和第四月的需求量超过了本厂的最大生产能力，如若要满足要求需要采用外协或者加班的方式解决。故最终计算两种生产方式的总成本时需要考虑：（1）matching demand如果采用外协第三月份有33-28=5台，第四月有29-28=1台，一共6台需要外协将工人工资代入计算，总的费用如下：Cost of level capacity:6080+72*4*2.2*25*8=$132800Matching demand:3510+6*2200+(39+72+84+84)*2.2*25*8=$139470Matching demand比Level capacity的花费更多。（2）matching demand如果采用加班加班：一件产品加班费用为2.6*600=15602200，因而可以采用加班的方式生产；每月加班总工时为25*8*20%*84=3360，满足生产需求，采用加班的总花费：3510+(39+72+84+84)*2.2*200+2.6*600*6=135630132800 ，Matching demand比Level capacity的花费更多。3.分析：(1)从成本计算的结果来看采用均衡式生产的费用最少(2) 相比市场匹配，均衡生产具有以下优势：a.减少了寻找，开发新材料供应来源的成本。b.只是用最具效率的机器生产。c.每个产品的劳动力和材料成本都很低，因为生产系统的周期操作使流程的频繁启动和暂停大大减少。d.因为工人对其工作非常熟练，使得生产监管简化，废料率降低。e.工人旷工缺勤数会较少。(3) 市场匹配的生产方式总是需要招聘或辞退工人，使得工厂生产处于不稳定的状态；需要外协，无法自身保证外协加工质量；需要加班，可能会导致工人的工作热情不高；需要频繁召入新工人，新工人经验不足，会给产品的生产质量带来一定的负面影响。4.综上所述，最终决定采用均衡生产的生产方式。四制定综合生产计划(Aggregate Planning)均衡生产综合生产计划如下表:1234567Aggregate planQuarterAggregate demandPlanned outputsWorkers requiredWorkers hiredWorkers laid offLevel capacity with inventory1132472018224247200333247200429247200五生产能力粗平衡(Rough-Cut Capacity Planning)如下表：Quarter final assembly hours1234Production24242424Final assembly hours3600360036003600Assemble capacity hours42004200 42004200Final machine hours10800108001080010800Machine capacity hours13050130501305013050 对比结果得，Final assembly hours Assemble capacity hours，Final machine hours Machine capacity hours。说明采用均衡生产说明生产能力满足要求，不需要加班或者外协。六制定主生产计划(Master Production Schedule)Quarter 1Quarter 2Quarter 3Quarter 4Weekno.1234123412341234Total demand13243329Beginning inventory10212112Required production6666666666666666Ending inventory2121127注：weeks no.代表实际生产周而非每月的前四周七制定MRP,CRP(Material Requirement Planning,Capacity Requirement Planning)1.制定MRP 各个零件选择用Lot For Lot的生产方式。由于是均衡生产，故每一季度的MRP相同，故做一个季度的MRP。由于各零件存在提前期，2周，因此每个生产月的前一个月也纳入MRP的制定中，由于在POM软件输入限制，在制定MRP时决定液压缸的生产周为3，4，5，6周，故用软件POM计算可得如下结果：* MATERIALS REQUIREMENTS PLANNING (MRP) *=PROBLEM NAME: YYG=Item Level Lead On Safety Already LotCode Code Time Hand Stock Allocated SizeYYG 0 0 10 6 4 LFL-Week Number: 1 2 3 4 5 6 -Gross Requirements 0 0 6 6 6 6Scheduled Receipts 0 0 0 0 0 0Available 0 0 0 0 0 0Net Requirements 0 0 6 6 6 6Planned Order Receipts 0 0 6 6 6 6Planned Order Releases 0 0 6 6 6 6-=Item Level Lead On Safety Already LotCode Code Time Hand Stock Allocated SizeHSG 1 2 0 0 0 LFL-Week Number: 1 2 3 4 5 6 -Gross Requirements 0 0 6 6 6 6Scheduled Receipts 0 0 0 0 0 0Available 0 0 0 0 0 0Net Requirements 0 0 6 6 6 6Planned Order Receipts 0 0 6 6 6 6Planned Order Releases 6 6 6 6 0 0-=Item Level Lead On Safety Already LotCode Code Time Hand Stock Allocated SizeGT-1 1 2 0 0 0 LFL-Week Number: 1 2 3 4 5 6 -Gross Requirements 0 0 6 6 6 6Scheduled Receipts 0 0 0 0 0 0Available 0 0 0 0 0 0Net Requirements 0 0 6 6 6 6Planned Order Receipts 0 0 6 6 6 6Planned Order Releases 6 6 6 6 0 0-=Item Level Lead On Safety Already LotCode Code Time Hand Stock Allocated SizeGT-2 1 2 0 0 0 LFL-Week Number: 1 2 3 4 5 6 -Gross Requirements 0 0 6 6 6 6Scheduled Receipts 0 0 0 0 0 0Available 0 0 0 0 0 0Net Requirements 0 0 6 6 6 6Planned Order Receipts 0 0 6 6 6 6Planned Order Releases 6 6 6 6 0 0-=Item Level Lead On Safety Already LotCode Code Time Hand Stock Allocated SizeFL 1 2 0 0 0 LFL-Week Number: 1 2 3 4 5 6 -Gross Requirements 0 0 12 12 12 12Scheduled Receipts 0 0 0 0 0 0Available 0 0 0 0 0 0Net Requirements 0 0 12 12 12 12Planned Order Receipts 0 0 12 12 12 12Planned Order Releases 12 12 12 12 0 0-=Item Level Lead On Safety Already LotCode Code Time Hand Stock Allocated SizeGD 1 2 0 0 0 LFL-Week Number: 1 2 3 4 5 6 -Gross Requirements 0 0 6 6 6 6Scheduled Receipts 0 0 0 0 0 0Available 0 0 0 0 0 0Net Requirements 0 0 6 6 6 6Planned Order Receipts 0 0 6 6 6 6Planned Order Releases 6 6 6 6 0 0-=Item Level Lead On Safety Already LotCode Code Time Hand Stock Allocated SizeEH 1 2 0 0 0 LFL-Week Number: 1 2 3 4 5 6 -Gross Re