资源描述:
《demand forecasting for inventory control forecast sensitivity》由会员上传分享,免费在线阅读,更多相关内容在工程资料-天天文库。
1、Chapter8ForecastSensitivity8.1IntroductionAlongthesupplychain,indistributioncenters,stores,dealers,soforth,forecastsareincontinualneedforinventorydecisionstoprojecttheflowofdemandsoverthefuturemonthsforeachitemstocked.Themoreaccuratetheforecasts,thebettertheinventorydecisions
2、andthemoreprofitabletheentity.A10%decreaseinthemeasureoftheforecasterrorwillresultinapproximatelya10+percentdecreaseintheamountofsafetystockneeded.Thisreducedstockisveryhelpfultotheprofitmarginontheinventorysystem.Inthischapter,aseriesofsimulationrunsaredevelopedtoapprisethef
3、ore-casteronhowsomeelementsinforecastingaffecttheaccuracyoftheforecasts.Forthispurpose,theforecastaccuracyismeasuredbythecoefficientofvariation,cov,ofthe1-monthaheadforecasterror.Afirstseriesoftestsconcernthenumberofmonthsofdemandhistorytouseindevelopingtheforecasts.Thecovism
4、easuredasthehistoryofdemandsrangefrom6to48monthsandtheforecastsareforthehorizontalandtrenddemandpatterns.Asecondseriesoftestsareaimedatmeasur-inghowforecastaccuracydependsonthechoiceofparametersandforecastmodelselected.Threeseparatesimulationsarerun;oneforthehorizontaldemandp
5、attern,anotherforthetrenddemandpattern,andyetanotherfortheseasonaldemandpat-tern.Athirdseriesoftestsdemonstratehowdamagingoutlierdemandsaretotheforecastsandtheforecastaccuracy.Twoexamplesaregiven,oneforahorizontaldemandpatternandanotherforatrenddemandpattern.8.2CovbyNMHwhenHo
6、rizontalDemandsandForecastsAsimulationisruntodeterminehowtheaccuracyoftheforecastisaffectedasthenumberofmonthsofhistory(NMH)varieswhenthedemandpatternishorizontalandahorizontalforecastmodelisapplied.Inthissimulation,theNMHofdemand©SpringerInternationalPublishingSwitzerland201
7、5107N.T.Thomopoulos,DemandForecastingforInventoryControl,DOI10.1007/978-3-319-11976-2_81088ForecastSensitivityTable8.1 AveragecovfromNMHCov25samplesbynumberofmonthshistory,NMH,using60.362thehorizontalmovingaver-120.346ageforecastmodel180.297240.292300.303360.316420.320480.318
8、historyisrandomlygeneratedfromahorizontaldemandpatternwheretheindi-v