【正文】 U+RT)1+(SU+RT)2+…+(SU+RT) n queue setup process wait move 1 2 n W/C …….. WIP 55 Expected Queueing Time Activation Queueing Time Assumption: M/M/1queueing system E(Q) = a/[s(as)] 。 前置時間 : 1期間 0 1 2 3 4 5 6 7毛需求排程到貨預估在手量計劃核發(fā) 2 5 0 2 0 0 2 5 0 1 5 0 2 0 0 3 0 0 1 5 0 2 5 0 料件 110固定數(shù)量訂購 。 前置時間 : 3期間 0 1 2 3 4 5 6 7毛需求排程到貨預估在手量計劃核發(fā) 2 4 0 0料件 122固定數(shù)量訂購 。 LT ? – not enough capacity ? Actual output ? actual input – work released late, may run out of work – feeding w/c behind schedule, idle capacity, late order Dispatching Rules ? First e, first served (FCFS) ? Earliest Job Due Date (EDD) ? Earliest Operation Due Date (ODD) ? Operation start dates ? Critical ratios (CR) ? Shortest process time (SPT) ? Other methods 79 Dispatching Rules Dis p a t c h i ng R u l eJ ob P roc e s sT i m e(da ys )A rri va lD a t eD ueD a t eO pe ra t i onD ue D a t eF C F S E DD ODD SPTA 4 223 245 2332 4 1 3B 1 224 242 2393 2 2 1C 5 231 240 2404 1 3 4D 2 219 243 2421 3 4 280 Capacity Management Pla nni ngHoriz onE xte nt T imePeri odsDec isio ns T ec hni que sRe sourc epla nni ng(lo ng ra ng e)Bey ondone y earMonth l yQuar te rl yY ea rl yPla nt co nstru ct ionE qui pment Proc.Manp ower pla nni ngGrossca lc u la t ionBOLOper at inghori zo n p la n(medi um r an ge )Up toone y earW ee kl y Manp ower tra nsfersW ork pla n ad just mentsAlt er na t e rou ti ngMake /Bu ySubco ntr ac t ingCa pa cit yre qui re mentspla nni ngE xe cu t ion(short ra nge )One tofourwee ksDai l yW ee kl yOrde r re l ea seOver ti meAlt er na t e rou ti ngOrde r ove rl ap pin gOper at ionseque nc ingI/O co ntr o l81 製造環(huán)境特性 特性 Job Shop Repetitive/Batch 產品定位策略 Maketoorder Maketostock Engineertoorder Assembletoorder 產量 低 高 批量 分攤 setup cost 1 Queue, move, wait time 高 (70% ~90%) 低 產能 Standard hours Cycle time Routings 變動 固定 Dispatching 複雜 FCFS layout 功能別佈置 產品別佈置 SFC 推式 (push) 拉式 (pull) Reporting detail 高 低 82 製造環(huán)境 比較 OneofaKind Fixed location Fixed by job site Trucks, cranes Single product High Very long Satellites, construction Plant Organization Routing Material Handling Product Mix Amount WIP Time to Manufacture Examples Job Shop Variable by product Functional departments Fork lifts, tote bins Many products High Variable by product Tools, furniture Repetitive Fixed by assembly line Fixed by line Conveyors, containers Similar products Low Short Auto assembly, tires Flow Shop Fixed by plant Fixed by plant Conveyors, pipelines Similar products Low Short with long runs Oil, steel, cement Source: APICS, CPIM materials 1998 83 Conclusions ? Managing order LTs requires managing both priority and capacity ? Capacity plans should use the broadest possible product groups that go through similar manufacturing operations ? Capacity must be adequate to support the MPS and handle additional unplanned demands 。 前置時間 : 4期間 0 1 2 3 4 5 6 7毛需求排程到貨預估在手量計劃核發(fā) 6 0 0 061 CRP Computation ? Setup time putation for planned order ? Run time putation for planned order ? Setup time putation for open order ? Run time putation for open order ? CRP load report 62 Planned Order Releases W e e kPa r t 1 2 3 4 5 6 71001101211222004002400600025040000150500240002004000600030040024000150400240002504000063 Setup Time Matrices for FG 週零件 1 2 3 4 5 6 7W C 1 100110121122合計300003030152507030150751203015250703015004530152575145301525070W C 2 100110121122合計010025350100010010150250100253501015025010001001015025W C 3 100110121122合計0015015000303000150150003030001530450015015000303064 Run Time Matrices for FG 週零件 1 2 3 4 5 6 7W C 1 100110121122合計5000005006252006000142537520003000357550025060001350750200009503752006003000417562520060001425W C 2 100110121122合計03000450048000300003000375600097503000450048000300600090003000030003006000900W C 3 100110