DIEN D A N
Dieu do nhan qua va Pareto -
Cdng CU kiem soat chat Imrng hieu qua
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Tdng cgc Ti§u chuin Do lUdng Chit lifpng Bd Khoa hpc vd Cdng ngh$
d nhieu nudc tren the gidi, dac biet la Nhat Ban va My, bieu dd nhdn qua va Pareto ia nhihig cdng cu Itiem soat chat liTgfng dufdc suT dting rdng rai va t h i hi§n rd tinh hi^u qua cua nd trong qua trinli san xua), kinh doanh. T^i Viet Nam, cac cdng cu kiem soat chat iiTdng nay tuy khdng mdi nhiAig rt ddigrc pho bien va ap dung. Thdng qua bai vi§'t diTdi d§y, tac gia hy vpng cac to chdc/doanh nghiep co them thdng tin de lufa chpn thufc hanh cac bilu dd nay, gdp phan kiem soat chS't Idigfng hieu qua.
Bieu do nhan qua
Nam 1953, Gido sU ngUdi Nhat Ban Ishikawa (1915-1989) da khdi qudt quan diem, y kien eiia cdc ky sU tai mpt nhd may ddng tdu dudi dang mpt bieu dd nhan - qua. Khi bieu dd nay dUdc dUa vao sii dung trong thtfc te, nd da chufng minh dUdc tinh hdp ly, hifu Ich, sau dd dUdc phd bien rdng rdi tai nhilu cdng ty d Nhdt Ban va ngay nay da dUde dp dung tai nhieu nUde tren the gidi.
Bieu do nhan qua Id mpt edng cu giiip td chiic/doanh nghiep dUa ra nhufng nhdn dinh nham tim ra nguyen nhan gd'c re eua van de ttf mpt hien tUdng quan sdt tha'y hodc ed the xay ra. Bieu dd nhan qua cdn minh hpa cho mdi quan he nhdn qua giCfa cdc nguyen nhan khdc nhau dUdc xdc dinh vdi tdc dpng bode hien tUdng dUdc quan sdt thd'y.
Bieu dd nhan qua ed dang gid'ng nhu mdt eon ea, trong dd cd eac xUdng trung tam, xUdng chinh, phu. Cu the:
XUdng trung tam: Dd la nhCfng van de, tdc ddng ed the la: Chat lUdng san p h i m (cd san
p h i m , ldi, ty le ldi...); ket qua boat dpng (hieu suit ldm viec, thdi ban giao hdng...).
XUdng chinh va phu: DUde the hien thdng qua nhCfng nguyen nhan dien hinh: Ddi vdi sdn xudt gdm 5M (Man Con ngUdi, Machine Mdy mdc. Method PhUdng phdp. Material Nguyen vat lieu, Measurement Stf do ludng); ddi vdi dich vu gdm 5P (People Con ngUdi, Process
Qud trtnh. Place Dia diem.
Provision Stf cung cap. Patron Khdeh hdng).
De xay difng mpt bieu dd nhdn qud hieu qua, mang lai nhilu ldi ich trong phan tich vd thtfc hdnh, to chifc/doanh nghiep c i n nghien cufu them 4W: Who Ai ldm; What Ldm cdi gi; When
Khi ndo; Where 6 ddu? Gido sU Ishikawa da diic ket viec xay dtfng bieu dd nhdn qua gdm 10 budc sau:
Budc 1: Vach rd nguyen nhan tdc ddng hoac hien tUdng anh hudng den chat lUdng san p h i m / dich vu.
Budc 2: Ddt cdc hien tUdng;, tdc ddng d ben phai trong m S
cdi hop. Ve mdt dUdng xUdng sd'ng trung tam hudng ddn hop dd.
Budc 3: Suf dung phUdng phap nao cdng (huy ddng tri nao tap the), ttfng budc tiep can xdc dinh cdc nguyen nhan chinh va vaa d l cd the xay ra.
Budc 4: Moi nguyen nhan chinh ddt trong mpt cdi hop va ket noi vdi xUdng trung tam bdi mpt dudng nghieng. Td chiic/
doanh nghipp eIn phai linh boat trong viec xdc dinh xUdng nguyen nhan chinh, thdng thudng cdc nguyen nhdn chinh cd the dUdc xdc dinh theo 5M (trong san xud't) hoac 5P (trong dich vu).
Trong ca hai qua t r t n h nay, mdi trudng vd do lUdng cung thUdng dUdc suf dung.
Budc 5: Xac dinh cdc nguyfen n h a n phu ben canh cdc nguy§n n h a n chinh, dUa vdo trong bieu dd.
Budc 6: Tiep tuc tim hiiu them cac nguyen n h a n cd the cho den khi moi n h a n h tim r a dUcfc mdt nguyen n h a n gdc r l . Vi§c tiep tuc tim r a cac nguy§n nhdn giup d l y m a n h hieu biet sau hdn vl
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K H O A H O C s°*^^"9^^ 2011Hoat tfdng ^ -- ^u - .... r,/^....
DIEN D A N
qud trinh. Qua trinh dat cau hdi tim nguyen n h a n ed the ket thuc khi nguyen nhan dUde kiem sodt theo yeu clu da ddt ra.
Budc 7: K i l m tra gid tri logic ciia mdi chudi nguyen nhdn.
Budc 8: Kiem tra tinh d l y dii ciia bieu dd.
Budc 9: Ddt ten eho bieu dd.
Budc 10: Thdo ludn v l bieu do.
Viec xdy dtfng vd phan tich bieu dd nhan qua giiip td ehifc/
doanh nghiep hinh dung xuyen sud't todn bp nguyen nhan eua mpt van dl/hien tUdng, trong dd dae biet la viec xdc dinh dUdc nguyen nhan gd'c rd; gdi md ra cac hien tUdng vUdt ra ngoai gidi ban, giiip to chufc/doanh nghiep trong viec phat hien ra cdc nguyen nhan t i l m tang.
Dtfng dUde mdt bieu dd hieu qua la mdt nhiem vu khdng de dang, ed the ndi rang, nhCfng td chufc/doanh nghiep thdnh Qong trong giai quyet van d l kiem sodt chat lUdng la nhCfng ddn vi thdnh edng trong viec tao ra mdt bieu do nhan qua bCiu Ich. Khi xay dtfng bieu do nhan qua, viec huy dpng tri nao tap thd la rat c i n thiet trong viec phan tich vd tap hdp cdc nguyen nhan.
Viec xdc dinh t i m quan trpng cua cdc nguyen nhan, tdc dpng phai bang each suf dung cdc dCf lieu khach quan ed tinh khoa hpc vd logic. Khi mdi quan h.% giiJa nguyen nhan gdc r l va t i e dpng da dUdc xdc dinh, td chufc/doanh
nghipp c i n tien hdnh do lUdng chiing. Neu khdng the do lUdng, c i n cd gang tim nhUng dac tinh thay the phu hdp.
Td chiic/doanh nghiep cd the suf dung bieu dd nhan qud nhU mdt dang van ban. Van ban nay se dUdc cap nhat song song vdi viec thu thap dU lieu hodc thii nghiem cdc giai phdp khdc nhau nham gidi quyet van d l .
Bieu ltd Pareto (nguyen tac 80:20)
Nguyen t i e 80:20 dUde Vilfredo Pareto (1848-1923) Nhd kinh te hpc ngUdi Y khdm phd nam 1897 khi dng tinh cd nghien eiiu nhCfng quy luat v l eua cai vd thu nhap d nUde Anh the ky XIX. Ong nhan tha'y, theo mdu nghien eUu, h l u het lUdng thu nhdp va ciia cai thupc v l tay mpt nhdm ngUdi thieu so'.
Vao diu nhiing nam 50 cua the ky XX, Giao sU ngUdi My Joseph Juran (1904-2008) da tiep tuc Ung dung va khdm phd nguyen tac 80:20 ndy trong cdng cupc di tim chat lUdng cao cho san p h i m . Ong da gpi khdm phd ciia minh la "Nguyen tac Pareto"
(hay cdn gpi la nguyen tac 80:20).
Chinh nguyen tac 80:20 nay da trd thdnh linh hdn cho cupc each mang chat lUdng toan clu.
Ddng thdi, ong cCing dUa ra thuat ngCf "Sd' It trpng yeu Vital few"
de d l cap den sd lUdng nho cdc nguyen nhan nhtfng lai cd nbijfng tdc dpng ldn deii ket qua vd "Sd nhilu bijfu Ich Useful many" d l cap den ta't ea cdc yeu to khac vd nhCfng yeu td nay gidi thich nguyen nhdn gdy ra p h i n tdc dpng nhd hdn.
Nguyen t i e 80:20 khang dinh rang, mpt thieu sd' nguyen nhan
"nguyen lipu dau vao" hoac edng sufc thudng ddn den da so nhUng
Biiu do Pareto
ket qua "san pham diu ra" hoac nhCfng thanh qua. Dilu nay cd the dUdc hieu nhU sau: 80%
Idi/khuyet tat do 20% nguyen nhdn cd the gay ra; 80% ngan sdch chi cho thiet bi den ttf 20%
mat hang; 80% ldi nhuan den tif 20% khach hang; 80% phan nan tu 20% sU phuc vu cua td chUe/
doanh nghiep; 80% thdi gian ciia y td danh cho 20% benh nhan;
80% nhCfng quyet dinh dUa ra trong budi hpp den tU 20% ciia thdi gian hpp; 80% cai tien den ttf 20% nhan vien.
Con so' 80, 20 khdng cd nghia la diing hoan todn, d day Juran mudn ndi den: Chung ta c i n tap trung vao cdc van d l "So' It trpng yeu" (nam trong 20%) de dUa ra cdc bien phdp gidm thieu sai ldi, cai tien nhCfng van d l quan trpng nha't lidn quan den c h i t lUdng san phlmf Vay bieu dd Pareto dupc sii dung khi ndo? Pareto dupc suf dung de phdn tich cdc nguyen nhdn ciia van de, ddng thdi giiip xdc dinh nhanh ehdng cdc nguyen nhan chinh theo hudng true tiep.
Ca'u triic bieu dd Pareto bao gdm: Cdc biin sd tren true hodnh (gdm cdc yeu to: Khuyet tat; con ngUdi; thiet bi; phUdng phap;
nguyen vat lieu; thdi gian). Cdc bien sd tren true tung (gdm: Tiln te; chat lUdng; thdi gian; stf an
So thang 11.2011 xrys^ ) ; iJf\n 21
DIEN D A N
todn...). Cdc cot (the hidn do ldn ciia cdc bien tren true hoanh).
Dudng phdn trdm tich liiy.
Qua trtnh xdy dtfng bieu dd Pareto gdm 8 bUde sau:
Budc 1: Xdc dinh pham vi van d l md td chiic/doanh nghipp mudn cd nhilu thdng tin hdn ve cac ldi cd the xdy ra.
Budc 2: LUa chpn nhtfng nguyen nhdn hoac nhijfng vdn de cin dUdc xem xet (cd the sii dung ket hdp vdi bieu dd nhdn qua hodc Brainstorming Huy dpng tri ndo tap the).
Budc 3: Lifa chpn ddn vi do ludng cd y nghia nhdt lien quan den van d l cua td chUc/doanh nghiep, vi du: T i n s u i t hodc gid
7
ca.
Budc 4: Thu thdp sd lieu (bao gdm eiia cdc loai van de khdc nhau).
Budc 5: Lap bang tinh: Xdc dinh tdng sd Idi/khuyet tat eho mdi loai van d l vd tong sd cac Idi/khuyet tat cua td't ea cdc van dl. Tinh % Idi/khuyet tat cho mdi loai van d l khde nhau vd cdng liiy tien. Neu ed nhilu van d l khdng thudng xay ra hodc xay ra vdi ty le thd'p (< 10%) vd tdng cua chung < 15% thi tap hdp nhiJng van de dd lai trong mpt cot gpi la cdt "khdc"
Budc 6: Sap xep theo sd lUdng hodc ty le % eiia Idi/khuyet tat tif ldn nhd't den nhd nha't.
Budc 7: Ve bipu dd.
Budc 8: Dat ten cho bieu dd.
VI du: Ap dung nguyen t i e 80:20, ta cd the xdc dinh dUdc siic cdng, x\idc vd Id hdng la nguyen nhan chinh gay ra hien tUdng san p h i m due bi ldi (xem bang vd biiu do).
Muc tieu ciia viec xay dtfng va phdn tich Pareto Id phdn tdch
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104 42 20 10 ti 4 14 200
Ttfng tfch lOv
104 146 166 176 182 186 200
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r,2 21 10
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2 7 100
I'han trdm tich luy r,2 73 83 88 91 93 100
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Bi^u 66 Pareto
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Loai ktujy^t t^t
cdc Idi/khuyet tat eiia van d l ldm hai loai: "Vital' few" vd "Useful many" De ldm dUdc dilu nay, td chufc/doanh nghiep phai xdc dinh dUde diem duft gdy tren dUdng tdng p h i n trdm tich luy eiia bieu dd Pareto. Trong thtfc te, viec xdc dinh diem diit gay ciia dUdng
?ong Pareto trong nhilu trUdng hdp Id khong rd rang, khi dd ta cd the dilu chinh nguyen t i c 80:20.
Nguyen nhdn chinh ciia van d l dupe xdc dinh Id cdt cao nhat trong bieu dd Pareto, sau dd de'n cdc nguyen nhan thii 2, 3,... tUdng ling vdi dp cao cua cdt tiep theo.
Sau qud trtnh thtfc hien cdc bien phdp loai bo Idi/khuyet tdt vd cai tien, dudng cong Pareto "mdi"
dUde ve tren cung mpt bieu dd vdi dudng Pareto "gd'c" Dilu nay giiip ehi ra nhiing tdc ddng ciia stf thay ddi. Sd' lieu thu t h a p cua cac van d l hodc nguyen n h a n giong
nhau nhLfn(,f lai den tU cac dia diem, thic't hi khac nhau phai du'o'c the hien Irong cac bieu do Pareto sat canh nhau. Ddi vdi do'n \i do lu'o'ng cua cac van de hoac nguyen nhan giong nhau, VI du tan suat, gia ca. phai difdc sap xep lan lu'o't.
Pareto la mot trong nhCfng cong cu kiem soat chat lifcfng manh nhat. NhCfng van de xay ra thu'dng XUVCMI nhat khong phai lut)n la quan trong nhat, Bdi vay, to chu'c/doanh nghiep phai luon xac dinh: Nhifng gi tac dong ldn nhat tdi nhiifng muc tieu kinh doanh va khach hang ciia minh. Td chUc/doanh nghiep CO the dat dUo'c nhieu tac dung hdn nifa tU viec siJf dung bieu do Pareto, sau khi da hoan thanh viec thifc hien bieu dd nhan qua ddi vdi cac nguyen nhan gdc re can dUdc Uu tien giai quyet •
