概率统计分布表

精品文档精心整理精品文档可编辑的精品文档标准正态表x0.000.010.020.030.040.050.060.070.080.090.00.50000.50400.50800.51200.51600.51990.52390.52790.53190.53590.10.53980.54380.54780.55170.55570.55960.56360.56750.57140.57530.20.57930.58320.58710.59100.59480.59870.60260.60640.61030.61410.30.61790.62170.62550.62930.63310.63680.64060.64430.64800.65170.40.65540.65910.66280.66640.67000.67360.67720.68080.68440.68790.50.69150.69500.69850.70190.70540.70880.71230.71570.71900.72240.60.72570.72910.73240.73570.73890.74220.74540.74860.75170.75490.70.75800.76110.76420.76730.77040.77340.77640.77940.78230.78520.80.78810.79100.79390.79670.79950.80230.80510.80780.81060.81330.90.81590.81860.82120.82380.82640.82890.83150.83400.83650.83891.00.84130.84380.84610.84850.85080.85310.85540.85770.85990.86211.10.86430.86650.86860.87080.87290.87490.87700.87900.88100.88301.20.88490.88690.88880.89070.89250.89440.89620.89800.89970.90151.30.90320.90490.90660.90820.90990.91150.91310.91470.91620.91771.40.91920.92070.92220.92360.92510.92650.92790.92920.93060.93191.50.93320.93450.93570.93700.93820.93940.94060.94180.94290.94411.60.94520.94630.94740.94840.94950.95050.95150.95250.95350.95451.70.95540.95640.95730.95820.95910.95990.96080.96160.96250.96331.80.96410.96490.96560.96640.96710.96780.96860.96930.96990.97061.90.97130.97190.97260.97320.97380.97440.97500.97560.97610.97672.00.97720.97780.97830.97880.97930.97980.98030.98080.98120.98172.10.98210.98260.98300.98340.98380.98420.98460.98500.98540.98572.20.98610.98640.98680.98710.98750.98780.98810.98840.98870.98902.30.98930.98960.98980.99010.99040.99060.99090.99110.99130.99162.40.99180.99200.99220.99250.99270.99290.99310.99320.99340.99362.50.99380.99400.99410.99430.99450.99460.99480.99490.99510.99522.60.99530.99550.99560.99570.99590.99600.99610.99620.99630.99642.70.99650.99660.99670.99680.99690.99700.99710.99720.99730.99742.80.99740.99750.99760.99770.99770.99780.99790.99790.99800.99812.90.99810.99820.99820.99830.99840.99840.99850.99850.99860.99863.00.99870.99870.99870.99880.99880.99890.99890.99890.99900.99903.10.99900.99910.99910.99910.99920.99920.99920.99920.99930.99933.20.99930.99930.99940.99940.99940.99940.99940.99950.99950.99953.30.99950.99950.99950.99960.99960.99960.99960.99960.99960.99973.40.99970.99970.99970.99970.99970.99970.99970.99970.99970.99983.50.99980.99980.99980.99980.99980.99980.99980.99980.99980.99983.60.99980.99980.99990.99990.99990.99990.99990.99990.99990.99993.70.99990.99990.99990.99990.99990.99990.99990.99990.99990.99993.80.99990.99990.99990.99990.99990.99990.99990.99990.99990.99993.91.00001.00001.00001.00001.00001.00001.00001.00001.00001.0000

n\p0.0050.0100.0250.0500.1000.2500.7500.9000.9500.9750.9900.99510.00000.00020.00100.00390.01580.10151.32332.70553.84155.02396.63497.879420.01000.02010.05060.10260.21070.57542.77264.60525.99157.37789.210310.596630.07170.11480.21580.35180.58441.21254.10836.25147.81479.348411.344912.838240.20700.29710.48440.71071.06361.92265.38537.77949.487711.143313.276714.860350.41170.55430.83121.14551.61032.67466.62579.236411.070512.832515.086316.749660.67570.87211.23731.63542.20413.45467.840810.644612.591614.449416.811918.547670.98931.23901.68992.16732.83314.25499.037112.017014.067116.012818.475320.277781.34441.64652.17972.73263.48955.070610.218913.361615.507317.534520.090221.955091.73492.08792.70043.32514.16825.898811.388814.683716.919019.022821.666023.5894102.15592.55823.24703.94034.86526.737212.548915.987218.307020.483223.209325.1882112.60323.05353.81574.57485.57787.584113.700717.275019.675121.920024.725026.7568123.07383.57064.40385.22606.30388.438414.845418.549321.026123.336726.217028.2995133.56504.10695.00885.89197.04159.299115.983919.811922.362024.735627.688229.8195144.07474.66045.62876.57067.789510.165317.116921.064123.684826.118929.141231.3193154.60095.22936.26217.26098.546811.036518.245122.307124.995827.488430.577932.8013165.14225.81226.90777.96169.312211.912219.368923.541826.296228.845431.999934.2672175.69726.40787.56428.671810.085212.791920.488724.769027.587130.191033.408735.7185186.26487.01498.23079.390510.864913.675321.604925.989428.869331.526434.805337.1565196.84407.63278.906510.117011.650914.562022.717827.203630.143532.852336.190938.5823207.43388.26049.590810.850812.442615.451823.827728.412031.410434.169637.566239.9968218.03378.897210.282911.591313.239616.344424.934829.615132.670635.478938.932241.4011228.64279.542510.982312.338014.041517.239626.039330.813333.924436.780740.289442.7957239.260410.195711.688613.090514.848018.137327.141332.006935.172538.075641.638444.1813249.886210.856412.401213.848415.658719.037328.241233.196236.415039.364142.979845.55852510.519711.524013.119714.611416.473419.939329.338934.381637.652540.646544.314146.92792611.160212.198113.843915.379217.291920.843430.434635.563238.885141.923245.641748.28992711.807612.878514.573416.151418.113921.749431.528436.741240.113343.194546.962949.64492812.461313.564715.307916.927918.939222.657232.620537.915941.337144.460848.278250.99342913.121114.256516.047117.708419.767723.566633.710939.087542.557045.722349.587952.33563013.786714.953516.790818.492720.599224.477634.799740.256043.773046.979250.892253.67203114.457815.655517.538719.280621.433625.390135.887141.421744.985348.231952.191455.00273215.134016.362218.290820.071922.270626.304136.973042.584746.194349.480453.485856.32813315.815317.073519.046720.866523.110227.219438.057543.745247.399950.725154.775557.64843416.501317.789119.806321.664323.952328.136139.140844.903248.602451.966056.060958.96393517.191818.508920.569422.465024.796729.054040.222846.058849.801853.203357.342160.27483617.886719.232721.335923.268625.643329.973041.303647.212250.998554.437358.619261.58123718.585819.960222.105624.074926.492130.893342.383348.363452.192355.668059.892562.88333819.288920.691422.878524.883927.343031.814643.461949.512653.383556.895561.162164.18143919.995921.426223.654325.695428.195832.736944.539550.659854.572258.120162.428165.47564020.706522.164324.433026.509329.050533.660345.616051.805155.758559.341763.690766.76604121.420822.905625.214527.325629.907134.584646.691652.948556.942460.560664.950168.05274222.138523.650125.998728.144030.765435.509947.766354.090258.124061.776866.206269.33604322.859524.397626.785428.964731.625536.436148.840055.230259.303562.990467.459370.61594423.583725.148027.574629.787532.487137.363149.912956.368560.480964.201568.709571.89264524.311025.901328.366230.612333.350438.291050.984957.505361.656265.410269.956873.1661T分布n\p0.7500.8000.8500.9000.9500.9750.9900.9950.99750.99900.999511.00001.37641.96263.07776.313812.706231.820563.6567127.3213318.3088636.619220.81651.06071.38621.88562.92004.30276.96469.924814.089022.327131.599130.76490.97851.24981.63772.35343.18244.54075.84097.453310.214512.924040.74070.94101.18961.53322.13182.77643.74694.60415.59767.17328.610350.72670.91951.15581.47592.01502.57063.36494.03214.77335.89346.868860.71760.90571.13421.43981.94322.44693.14273.70744.31685.20765.958870.71110.89601.11921.41491.89462.36462.99803.49954.02934.78535.407980.70640.88891.10811.39681.85952.30602.89653.35543.83254.50085.041390.70270.88341.09971.38301.83312.26222.82143.24983.68974.29684.7809100.69980.87911.09311.37221.81252.22812.76383.16933.58144.14374.5869110.69740.87551.08771.36341.79592.20102.71813.10583.49664.02474.4370120.69550.87261.08321.35621.78232.17882.68103.05453.42843.92964.3178130.69380.87021.07951.35021.77092.16042.65033.01233.37253.85204.2208140.69240.86811.07631.34501.76132.14482.62452.97683.32573.78744.1405150.69120.86621.07351.34061.75312.13142.60252.94673.28603.73284.0728160.69010.86471.07111.33681.74592.11992.58352.92083.25203.68624.0150170.68920.86331.06901.33341.73962.10982.56692.89823.22243.64583.9651180.68840.86201.06721.33041.73412.10092.55242.87843.19663.61053.9216190.68760.86101.06551.32771.72912.09302.53952.86093.17373.57943.8834200.68700.86001.06401.32531.72472.08602.52802.84533.15343.55183.8495210.68640.85911.06271.32321.72072.07962.51762.83143.13523.52723.8193220.68580.85831.06141.32121.71712.07392.50832.81883.11883.50503.7921230.68530.85751.06031.31951.71392.06872.49992.80733.10403.48503.7676240.68480.85691.05931.31781.71092.06392.49222.79693.09053.46683.7454250.68440.85621.05841.31631.70812.05952.48512.78743.07823.45023.7251260.68400.85571.05751.31501.70562.05552.47862.77873.06693.43503.7066270.68370.85511.05671.31371.70332.05182.47272.77073.05653.42103.6896280.68340.85461.05601.31251.70112.04842.46712.76333.04693.40823.6739290.68300.85421.05531.31141.69912.04522.46202.75643.03803.39623.6594300.68280.85381.05471.31041.69732.04232.45732.75003.02983.38523.6460310.68250.85341.05411.30951.69552.03952.45282.74403.02213.37493.6335320.68220.85301.05351.30861.69392.03692.44872.73853.01493.36533.6218330.68200.85261.05301.30771.69242.03452.44482.73333.00823.35633.6109340.68180.85231.05251.30701.69092.03222.44112.72843.00203.34793.6007350.68160.85201.05201.30621.68962.03012.43772.72382.99603.34003.5911360.68140.85171.05161.30551.68832.02812.43452.71952.99053.33263.5821370.68120.85141.05121.30491.68712.02622.43142.71542.98523.32563.5737380.68100.85121.05081.30421.68602.02442.42862.71162.98033.31903.5657390.68080.85091.05041.30361.68492.02272.42582.70792.97563.31283.5581400.68070.85071.05001.30311.68392.02112.42332.70452.97123.30693.5510410.68050.85051.04971.30251.68292.01952.42082.70122.96703.30133.5442420.68040.85031.04941.30201.68202.01812.41852.69812.96303.29603.5377430.68020.85011.04911.30161.68112.01672.41632.69512.95923.29093.5316440.68010.84991.04881.30111.68022.01542.41412.69232.95553.28613.5258450.68000.84971.04851.30061.67942.01412.41212.68962.95213.28153.5203460.67990.84951.04831.30021.67872.01292.41022.68702.94883.27713.5150470.67970.84931.04801.29981.67792.01172.40832.68462.94563.27293.5099480.67960.84921.04781.29941.67722.01062.40662.68222.94263.26893.5051490.67950.84901.04751.29911.67662.00962.40492.68002.93973.26513.5004500.67940.84891.04731.29871.67592.00862.40332.67782.93703.26143.4960510.67930.84871.04711.29841.67532.00762.40172.67572.93433.25793.4918520.67920.84861.04691.29801.67472.00662.40022.67372.93183.25453.4877530.67910.84851.04671.29771.67412.00572.39882.67182.92933.25133.4838540.67910.84831.04651.29741.67362.00492.39742.67002.92703.24813.4800550.67900.84821.04631.29711.67302.00402.39612.66822.92473.24513.4764560.67890.84811.04611.29691.67252.00322.39482.66652.92253.24233.4729570.67880.84801.04591.29661.67202.00252.39362.66492.92043.23953.4696580.67870.84791.04581.29631.67162.00172.39242.66332.91843.23683.4663590.67870.84781.04561.29611.67112.00102.39122.66182.91643.23423.4632600.67860.84771.04551.29581.67062.00032.39012.66032.91463.23173.4602610.67850.84761.04531.29561.67021.99962.38902.65892.91273.22933.4573620.67850.84751.04521.29541.66981.99902.38802.65752.91103.22703.4545630.67840.84741.04501.29511.66941.99832.38702.65612.90933.22473.4518640.67830.84731.04491.29491.66901.99772.38602.65492.90763.22253.4491650.67830.84721.04481.29471.66861.99712.38512.65362.90603.22043.4466660.67820.84711.04461.29451.66831.99662.38422.65242.90453.21843.4441670.67820.84701.04451.29431.66791.99602.38332.65122.90303.21643.4417680.67810.84691.04441.29411.66761.99552.38242.65012.90153.21453.4394690.67810.84691.04431.29391.66721.99492.38162.64902.90013.21263.4372700.67800.84681.04421.29381.66691.99442.38082.64792.89873.21083.4350710.67800.84671.04411.29361.66661.99392.38002.64692.89743.20903.4329720.67790.84661.04401.29341.66631.99352.37932.64592.89613.20733.4308730.67790.84661.04381.29331.66601.99302.37852.64492.89493.20573.4289740.67780.84651.04371.29311.66571.99252.37782.64392.89363.20413.4269750.67780.84641.04361.29291.66541.99212.37712.64302.89243.20253.4250760.67770.84641.04361.29281.66521.99172.37642.64212.89133.20103.4232770.67770.84631.04351.29261.66491.99132.37582.64122.89023.19953.4214780.67760.84631.04341.29251.66461.99082.37512.64032.88913.19803.4197790.67760.84621.04331.29241.66441.99052.37452.63952.88803.19663.4180800.67760.84611.04321.29221.66411.99012.37392.63872.88703.19533.4163810.67750.84611.04311.29211.66391.98972.37332.63792.88603.19393.4147820.67750.84601.04301.29201.66361.98932.37272.63712.88503.19263.4132830.67750.84601.04291.29181.66341.98902.37212.63642.88403.19133.4116840.67740.84591.04291.29171.66321.98862.37162.63562.88313.19013.4102850.67740.84591.04281.29161.66301.98832.37102.63492.88223.18893.4087860.67740.84581.04271.29151.66281.98792.37052.63422.88133.18773.4073870.67730.84581.04261.29141.66261.98762.37002.63352.88043.18663.4059880.67730.84571.04261.29121.66241.98732.36952.63292.87953.18543.4045890.67730.84571.04251.29111.66221.98702.36902.63222.87873.18433.4032900.67720.84561.04241.29101.66201.98672.36852.63162.87793.18333.40191000.67700.84521.04181.29011.66021.98402.36422.62592.87073.17373.39051200.67650.84461.04091.28861.65771.97992.35782.61742.85993.15953.3735F分布P=0.90n\m123567810152030139.8649.5053.5955.8357.2458.9159.4459.8661.2261.7462.2628.539.009.169.249.299.359.379.389.429.449.4635.545.465.395.345.315.275.255.245.205.185.1744.544.324.194.114.053.983.953.943.873.843.8254.063.783.623.523.453.373.343.323.243.213.1763.783.463.293.183.113.012.982.962.872.842.8073.593.263.072.962.882.782.752.722.632.592.5683.463.112.922.812.732.622.592.562.462.422.3893.363.012.812.692.612.512.472.442.342.302.25103.292.922.732.612.522.412.382.352.242.202.16113.232.862.662.542.452.342.302.272.172.122.08123.182.812.612.482.392.282.242.212.102.062.01133.142.762.562.432.352.232.202.162.052.011.96143.102.732.522.392.312.192.152.122.011.961.91153.072.702.492.362.272.162.122.091.971.921.87163.052.672.462.332.242.132.092.061.941.891.84173.032.642.442.312.222.102.062.031.911.861.81183.012.622.422.292.202.082.042.001.891.841.78192.992.612.402.272.182.062.021.981.861.811.76202.972.592.382.252.162.042.001.961.841.791.74212.962.572.362.232.142.021.981.951.831.781.72222.952.562.352.222.132.011.971.931.811.761.70242.932.542.332.192.101.981.941.911.781.731.67262.912.522.312.172.081.961.921.881.761.711.65282.892.502.292.162.061.941.901.871.741.691.63302.882.492.282.142.051.931.881.851.721.671.61P=0.99n\m123567810121416182014052.184999.505403.355624.585763.655928.365981.076022.476106.326142.676170.106191.536208.73298.5099.0099.1799.2599.3099.3699.3799.3999.4299.4399.4499.4499.45334.1230.8229.4628.7128.2427.6727.4927.3527.0526.9226.8326.7526.69421.2018.0016.6915.9815.5214.9814.8014.6614.3714.2514.1514.0814.02516.2613.2712.0611.3910.9710.4610.2910.169.899.779.689.619.55613.7510.929.789.158.758.268.107.987.727.607.527.457.40712.259.558.457.857.466.996.846.726.476.366.286.216.16811.268.657.597.016.636.186.035.915.675.565.485.415.36910.568.026.996.426.065.615.475.355.115.014.924.864.811010.047.566.555.995.645.205.064.944.714.604.524.464.41119.657.216.225.675.324.894.744.634.404.294.214.154.10129.336.935.955.415.064.644.504.394.164.053.973.913.86139.076.705.745.214.864.444.304.193.963.863.783.723.66148.866.515.565.044.694.284.144.033.803.703.623.563.51158.686.365.424.894.564.144.003.893.673.563.493.423.37168.536.235.294.774.444.033.893.783.553.453.373.313.26178.406.115.184.674.343.933.793.683.463.353.273.213.16188.296.015.094.584.253.843.713.603.373.273.193.133.08198.185.935.014.504.173.773.633.523.303.193.123.053.00208.105.854.944.434.103.703.563.463.233.133.052.992.94218.025.784.874.374.043.643.513.403.173.072.992.932.88227.955.724.824.313.993.593.453.353.123.022.942.882.83237.885.664.764.263.943.543.413.303.072.972.892.832.78247.825.614.724.223.903.503.363.263.032.932.852.792.74257.775.574.684.183.853.463.323.222.992.892.812.752.70267.725.534.644.143.823.423.293.182.962.862.782.722.66277.685.494.604.113.783.393.263.152.932.822.752.682.63287.645.454.574.073.753.363.233.122.902.792.722.652.60297.605.424.544.043.733.333.203.092.872.772.692.632.57307.565.394.514.023.703.303.173.072.842.742.662.602.55Excel公式1.正态分布函数Excel计算正态分布时，使用NORMDIST函数，其格式如下：NORMDIST（a，μ，σ，累积）其中，“累积”：若为TRUE，则输出分布函数值，即P{X≤a}；若为FALSE，则为概率密度函数值．示例：已知X服从正态分布，μ＝600，σ＝100，求P{X≤500}．输入公式NORMDIST(500,600,100,TRUE)得到的结果为0.158655，即P{X≤500}=0.158655．2、正态分布函数的反函数Excel计算正态分布函数的反函数使用NORMINV函数，格式如下：NORMINV（p，μ，σ），此公式计算a，使P{X≤a}=p3标准正态分布反函数=NORMSINV(0.975)3、t分布Excel计算t分布的值,采用TDIST函数，格式如下：TDIST（a，自由度，侧数）其中，“侧数”：指明分布为单侧或双侧：若为1，为单侧；此命令输出P{T>a}若为2，为双侧．此命令输出P{|T|>a}示例：设T服从自由度为24的t分布，求P(T>1.711)．已知t＝1.711，df=24，采用单侧，则T分布的值：TDIST(1.711,24,1)得到0.05，即P(T>1.711)=0.05．4.t分布的反函数Excel使用TINV函数得到t分布的反函数，格式如下：TINV（α，自由度）输出T分布的α/2分位点：t_α/2_(n)若求临界值tα(n)，则使用公式＝TINV(2*α,n)5.返回F分布的函数是FDISTFDIST(x,degrees_freedom1,degrees_freedom2)函数FDIST的计算公式为FDIST=P(F>x)，5.F分布的反函数FINV(probability,deg_freedom1,deg_freedom2)已知probability=P(F>x)，求x精品文档精心整理精品文档可编辑的精品文档第四章库存控制4.1概述一.库存和库存分类库存:处在储存状态的物资的数量库存分类:1.生产储备(周转储备)2.商品储备(流通储备)(周转储备)3.国家储备(安全储备)二.为什么周转仓库要进行库存控制？1.周转储备的二重性:一方面保障生产和流通的顺利进行；另一方面又闲置,延缓生产,需要付出费用。2.周转储备应当有一个合理的限度：太多了,不行：需要多的保管用具用料和人员，保管费用增加；太少了,不行：会造成缺货，产生缺货费用，也造成费用增加。应该不多不少,以能恰好保证生产和流通需要为限。3.合理库存:包括储备分布,储备品种结构,储备数量,储备费用合理。三.库存过程概述：库存过程可以分成：订货过程：从发出订货到订货成交为止。商流过程─┐库存增加进货过程：从订货成交到货物入库为止。物流过程─┘保管过程：从货物入库到货物出库为止。物流过程库存不变销售出库过程：从货物点交到货物出库发运止,商,物流过程库存减少四.库存控制的原理：为了控制库存量，由库存过程可知，可控制订货进货过程，也可控制销售出库过程。都可以达到目的。但是，控制销售出库过程，意味着限制用户的需求，影响社会需求，不好。所以最好采用通过控制订货进货过程的办法来控制库存量。这样，不但可主动控制库存量，而且不影响社会效益。因此，本章的思路，就是研究怎样通过控制订货进货过程的办法来控制库存量。五.订货策略的含义：包括三个方面的内容：１.什么时侯订货，即订货时机，或订货点。２.订多少，即订货点。３.如何实施，即订货方法。六.库存费用：１.订货费：含义：订货过程中发生的全部费用。包括差旅费，订货手续费，通讯费，招待费以及订货人员有关费用。特点：每一次订货中订货费与订货量的多少无关。若干次订货的总订货费与订货次数有关。公式：设一次订货费为c0,且每次订货费都相等,如在Ｔ期间内共订了ｎ次货，每次订货量为Ｑｏ，Ｔ期间内的总需求量(也即Ｔ期间内的总订货量)为Ｄ，则Ｔ期间内的总订货费为：C0QC0Q0图4-1可见，如Ｔ期间的总需求量Ｄ确定不变时，平均订货费的大小与订货批量成反比。如图4-1所示。２.保管费：含义：保管程中发生的全部费用。包括：入、出库时的装卸搬运堆码检验费用；保管用具用料费用；仓库房租水电费；保管人员有关费用；保管过程中的货损货差；保管物资资金的银行利息。特点：保管费用与保管数量的多少和保管时间的长短有关。设单位物资单位时间的保管费为c1，平均库存量为，则Ｔ期间的总保管费C1为：C1Q0图4-2C1Q0图4-2而Ｔ期间内的平均保管费为：可见平均保管费与订货批量成正比。如图4-2所示：QQ图4-3TQ0tR图4-4TQ0Qp对于持时到货的情况（图4-4），设进货的速率为p、销售的速率为R，订货批量为Q0，则所能达到的最高库存量Qmax为：T期间的平均库存量等于：所以T期间的平均保管费等于：3.进货费与购买费：含义：所谓进货费，就是进货途中的全部费用，即运杂费。包括：运费、包装费、装卸费、租赁费、延时费、货损货差等。购买费，即物资的原价。特点：进货费与购买费都与订货批量无关，批量订多订少都不安影响其总进货费和购买费。我们把这种与订货批量无关的费用称为固定费用，而把那些与订货批量有关的费用称作可变费用。因此，进货费与购买费是固定费用，而订货费、保管费、缺货费、补货费是可变费用。设单位物资的进货费为c3，单价为Ｋ，订货批量为Ｑ0，则总进货费与购买费Ｃ3为：Ｃ3=（c3+Ｋ）Ｑ0如为简化起见，用Ｋ表示固定费用，则Ｃ3可表示为：Ｃ3=（c3+Ｋ）Ｑ0≈ＫＱ0则平均固定费用：4.总费用：即各项费用的总和。即：Ｃ＝Ｃo＋Ｃ1＋Ｃ3总平均费用为：4.2经济订货批量一.概述：1.什么叫经济订货批量？所谓经济订货批量，就是从经济的观点出发在各种库存情况下，考虑怎样选择订货批量，使得库存总费用最省最经济。把这个使得库存总费用最省最经济的订货批量，叫经济订货批量。2.应用经济订货批量公式的意义：1）可以使得纵费用最省；2）可以达到库存控制的目的。3.应用经济订货批量公式的前提条件：1)公式适用于订货不受限制的情况。即什么时侯想订货就能订到货，想到哪里订就能到那里订。2)公式适用于单一品种的情况。3)公式不但适用于确定型，也适用于随机型。二.瞬时到货情况下的经济订货批量：RQtTRQtT2TR图4-5Q0由前节（4-9）式知：＝为求使最小的订货批量，令：即：＝Q0就是常说的经济订货批量，特记为：并且可求得：分别称作经济订货周期和瞬时到货的平均总变动费用。三.持时到货情况下的经济订货批量：Q0QtQ0Qt1TtRRpp图4-6根据4-10式，其库存平均总费用：＝＋＋其中，因：pt1＝ＲＴ＝Ｑo所以，而＝ＫＲ所以，为求使的总费用最小的订货周期Ｔ，令：得：即：说明：1.持时和瞬时的区别：；持时导致保管费用减少，从而导致Q*增大、订货周期增长而总平均可变费用减少。2.持时的效果相当于减少了保管费用，这是因为边进货边销售，有些货物没入库就销售掉了，使保管费用减少了。极端的情况下，所有货物都不入库，直接从供应地运到用户。皮包公司就是这么做的。3.持时因子当p趋向无穷大，则就趋向于1，持时也就变成了瞬时，所以瞬时乃是持时的特殊情况。4.3随机型库存控制方法一.概述：１.随机型：即库存参数中，至少有一个是随机变量的库存模型。所谓随机变量是其值是随时间而随机变化的，不能预先知道它在将来某一时刻确切的取值。２.主要的随机型库存参数有：1)需求速率Ｒ：单位时间的需求量。2)订货前置期Ｔk：从发出订货到所订货物入库为止的时间间隔。3)前置期需求量ＤL：订货前置期中的总需求量。4)订货点Qk的确定：订货点Qk是发出订货时的实际库存量。控制订货点Qk的高低，可以控制库存量。如Qk取得高，则所订货物到达入库时，原来库存物资还没销售完，从而库存水平升高，保管费用增加；如Qk太低，则所订货物到达入库时，原来的库存物资早已销售一空，产生了缺货，影响销售利润和库存满足率。所以Qk是一个进行库存控制的决策变量。Qk的最佳值最好是恰好等于“DL”，即：Qk＝“DL”但“DL”是随机变量，没有确定值，所以为了确定Qk，需要用到随机变量的知识来求解。一般，我们取Qk等于“DL”的平均值，再加上一个合适的保险裕量Qs，即：Qk＝＋Qs其中：是平均前置期需求量，Qs称为安全库存量。5)安全库存量Qs的求法：所谓安全库存，是在库存控制中为防止在订货前置期间内销售缺货而设置的库存量。是在平均前置期需求量上附加的一个保险裕量。如果“DL”服从正态分布,即: