Types of Forecasting Techniques. Qualitative Forecasting Methods. Quantitative Forecasting Methods. Quantitative Forecasting Methods

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1 MS0 Busiss orcasig Mhods Iroducio Lcurr: Dr. Iris Yug Room : P7509 l No.: msiris@ciyu.du.hk Imporac of Busiss orcasig I markig, oal dmad for producs mus b forcasd i ordr o pla oal promoioal ffor. I fiac, irs ras mus b prdicd so ha w capial acquisiios ca b plad ad fiacd. I prsol maagm, forcass of h umbr of workrs rquird i diffr job cagoris ar rquird i ordr o pla job rcruiig ad raiig programs. I producio schdulig, prdicios of dmad for ach produc li for spcific wks ad mohs allow h firm o pla producio schduls ad ivory maiac. I procss corol, forcass of h bhavior of h idusrial procss i h fuur ar rquird so ha h umbr of dfciv ims producd ca b miimizd. yps of orcasig chiqus Qualiaiv orcasig Mhods Quaiaiv orcasig Mhods Qualiaiv orcasig Mhods hs mhods ar usd wh hisorical daa ar scarc or o availabl a all. hy grally us xpr opiio o prdic fuur vs subjcivly Advaag usful wh hisorical daa ihr ar o availabl or ar scarc. or xampl, sals of w produc, virom ad chology ovr h log rm. Disadvaag Subjciv 3 Quaiaiv orcasig Mhods Quaiaiv orcasig Mhods hs mhods ar usd wh hisorical daa ar availabl. hy grally cosruc a forcasig modl from availabl daa or hory o do forcass. Advaag Objciv. Oc h udrlyig modl or chiqu has b chos, h corrspodig forcass ar drmid auomaically. hy ar fully rproducibl by ay forcasr. Disadvaag Nd daa Movig Avrag im Sris/Uivaria Mhods Expoial Dcomposiio Smoohig Mhods Quaiaiv orcasig Box-Jkis rasfr ARIMA ucio Modls Causal/Mulivaria Mhods Irvio Vcor Aalysis Auorgrssiv Modls Simpl ad MuliplRgrssio Mhods 5 6

2 im Sris/Uivaria Mhods h objciv of h im sris mhods is o discovr h par i h pas valus of a variabl. Assumig ha h hisorical par will coiu, his mhod xrapola i io h fuur ad us i o prdic fuur valus of h variabl of irs. Advaag rquir hisorical daa of o variabl oly; usful wh hisorical daa par dos o chag Disadvaag cao valua h impac of chags i ohr variabls. 7 Causal/Mulivaria Mhods Mak us of h rlaioship bw h variabl o b forcas ad h ohr variabls ha xplais is variaio o do h forcas. Advaag ca valua h impac of chags i ohr variabls. Disadvaags difficul o idify ohr variabls. rquir hisorical daa o all variabls of h modl. dpd o h fuur valus of h ohr variabls 8 Wha is a im Sris? im-sris Compos A im sris is a sris of obsrvaios o a paricular variabl collcd ovr a priod of im (usually a qually spacd irvals). s of im sris daa daily sock pric, xchag ras, ma mpraur mohly sals, moy supply, producio, ivory lvl quarrly GDP aually populaio rd Sasoal im-sris Cyclical Irrgular 9 0 rd Compo Cyclical Compo Ovrall upward or dowward movm Daa ak ovr a priod of yars Sals Upward rd Upward or dowward swigs May vary i lgh Usually lass - 0 yars Sals Cycl im

3 Sasoal Compo Upward or dowward swigs Rgular pars Obsrvd wihi yar Sals Summr Wir Sprig all im (Mohly or Quarrly) 3 Radom or Irrgular Compo Erraic, osysmaic, radom, rsidual flucuaios Du o radom variaios of Naur Accids Shor duraio ad o-rpaig orcas Error Aalysis 0 0 Radom rrors Cyclical ffcs o accoud for 0 0 rd o accoud for Sasoal ffcs o accoud for Accuracy Masurs orcas rror or rsidual Ma rror Ma absolu rror Ma squard rror Y ME MAE MSE 6 Accuracy Masurs Naïv Mhods Prcag rror PE ( Y ) 00 Naïv Modl Naiv rd Modl Ma prcag rror MPE PE Naiv Ra of Chag Modl Naiv Sasoal Modl Ma absolu prcag rror MAPE PE 7 Naiv rd ad Sasoal Modl 8 3

4 Naiv Modl Assum ha rc priod ar h bs prdicors of h fuur + Y Naiv Modl : Sals of ovs for h ABC compay (99-000) Quarr Yar Y 9 Naiv rd Modl Esima rd by akig h diffrc bw his ad las priod + Y + ( Y Y Y + ( Y Y ) 3 + ( 00) 900 ) Naiv Ra of Chag Modl or som purposs, h ra of chag migh b mor appropria ha h absolu amou of chag + Y Y Y Y 056 Y Y 3 00 Naiv Sasoal Modl Nx quarr h variabl will ak o h sam valu i did i h corrspodig quarr yar ago + Y 3 Y 750 Naiv rd ad Sasoal Modl Y 3 h rm forcass h sasoal pars ad h rmaiig rm avrags h amou of chag for h pas quarrs (rd). Y ( Y Y 3 Y ) + L+ ( Y ) 3

5 Naiv rd ad Sasoal Modl ( Y Y3) + ( Y3 Y) + L+ ( Y Y0) Y+ ( 600) hil s U-saisic his saisic allows a rlaiv compariso of formal forcasig mhods wih aïv approachs ad also squars h rrors ivolvd so ha larg rrors ar giv much mor wigh ha small rrors. 6 Dfiiio of hil s U-saisic U {( {( Y + + Y + ) / Y } Y ) / Y } Irprig hil s U-saisic U : h aïv mhod is as good as h forcasig chiqu big valuad. U < : h forcasig chiqu big usd is br ha h aïv mhod. h smallr h U- saisic, h br h forcasig chiqu is rlaiv o h aïv mhod. U > : hr is o poi i usig a formal forcasig mhod, sic usig a aïv mhod will produc br rsuls