chuong 3 SPC7tools.pdf

Thi gian: 27/9/2014

4/10/2014

7 Cng cu Quan ly cht lng c ban

7 Basic QC Tools

KIM SOAT QUA TRINH BNG PHNG PHAP THNG K ( SPC)

2 SPC: Statistical Process Control

Ni dung

Phn 1: gii thiu v SPC

Lch s v vai tr ca SPC

Qun tr cht lng v phn tch d liu

Phn 2: 7 cng c thng k c bn:

Mc ch p dng

Cch xy dng

Bi tp thc hnh

Mc tiu kha hc

Sau khi kt thuc kha hc, hc vin s:

Nhn thc c ngha v tm quan trng ca hot ng thng k v phn tch d liu

Hiu r v s dng c 7 cng c thng k c bn

p dng c cc cng c thng k c bn vo trong cng vic

Gp phn nng cao hiu qu hot ng cho cng ty

Lch s p dng v vai tr ca SPC

Walter A. Shewhart ti nh my AT&T's Western Electric pht trin, p dng control chart v khi nim kim sot cht lng qua thng k t 1924.

Trin khai kim sot cht lng qua thng k cho nhiu nh my quc phng Hoa K trong th chin II

Deming gii thiu k thut SPC vo nn cng nghip Nht Bn sau chin tranh

Cc cng ty Nht pht trin v p dng SPC rt mnh m trong h thng qun l cht lng theo TQM ca h

Lch s p dng v vai tr ca SPC

Kim tra cht lng c in c thc hin bng vic quan st nhng c tnh quan trng ca thnh phm v chp nhn / loi b thnh phm.

Ngc li vi iu , SPC s dng nhng cng c thng k quan st kt qu lm vic ca qu trnh sn xut/ cng vic nhm d on nhng sai lch quan trng m c th dn ti vic loi b sn phm.

Gi thit nn tng cho phng php SPC l bt k qu trnh sn xut no s sn xut sn phm c thuc tnh thay i nh so vi gi tr thit k, thm ch khi dy chuyn sn xut chy bnh thng, v nhng dao ng ny c th c phn tch thng k kim sot qu trnh.

Quyt nh da trn phn tch d liu l nguyn tc ca qun tr cht lng

7

Qun tr cht lng

Hng vo khch hng

Vai tr ca Lnh o

Tham gia ca mi ngi

Qun l theo qu trnh

Tip cn theo h thng

Ci tin lin tc Quyt nh da trn s kin

Quan h vi nh cung ng

Kt qu phn tch d liu l c s ra quyt nh

8

Quyt nh

u t u?

Ngun lc cn cung cp?

o to ci g?

Cho ai?

Sn phm no cn pht trin?

Ci tin ci g? u?

Khc phuc, Phng nga vn g?

Quyt nh phi da trn d liu

Quyt nh a trn cm tnh

thiu tin cy

Khong

co d

lieu

Qun l da trn d liu

Khng c qun l

Hng i khng

r rng

Ri ro cao

9

Nguyn tc k thut thng k

1. Thu thap so lieu

2. X ly so lieu

3. Phan tch so lieu

4. a ra c hoi cai tien

10

Cc cng c thng k

Biu line / biu ct / biu trn

07 cng c thng k c bn

07 cng c mi

Cc k thut ly mu

Cng c thng k nng cao: hi quy, phng sai

07 CNG C THNG K C BAN

1. PHIU KIM TRA

2. BIU PHN B

3. BIU XNG CA

4. BIU PARETO

5. BIU KIM SOAT

6. BIU PHN TAN

7. BIU PHN TNG

12

nh ngha khi nim Qu trnh (theo ISO9000:2005)

QU TRNH L tp hp cc hot ng c lin quan hoc tng tc ln nhau s dng ngun lc bin i u vo thnh u ra gia tng gi tr

SAN PHM L kt qu ca qu trnh

13

M HNH M TA QU TRNH

NHN LC PHNG TIN

PHNG PHAP L/GAM SAT

Cc hot ng hoc

qu trnh con

U VO

U RA

14

Mu dng cho thu thap d lieu hoc kim tra

Phieu San pham:

So lo:

LOAI KHUYET TAT SO LAN LAP LAI TONG SO %

Sai mau ///// ///// ///// ///// // 25 37%

Day ,mong ///// ///// / 12 18 %

Tong so khuyet tat 67 100% 15

Cng c 1: PHIU KIM TRA

PHIU KIM TRA

1. Mc ch p dng : thu thp d liu bng phng php n gin v phng nga vic qun kim tra

2. Phn loi:

2.1 Phiu thu thp d liu:

2.1.1 Phiu thu thp loi li/ khuyt tt

2.1.2 Phiu thu thp nguyn nhn

2.1.3 Phiu thu thp d liu phn b

2.2 Phiu dng kim tra:

2.2.1 Phiu checklist

2.2.2 Phiu t nh gi

16

Cch xy dng phiu kim tra

Thit k Phiu thu thp d liu

1. Xc nh r mc ch thu thp v mc tiu mong mun

2. Xc nh r cch thc thu thp : who , when , where,

cch thc

3. c tnh tng s lng d liu cn thu thp

4. Xc nh dng (format) ca phiu

5. p dng th

6. nh gi so vi mc tiu ra

7. p dng chnh thc

17

Cch xy dng phiu kim tra

Thit k Phiu dng kim tra

1. Xc nh r mc ch thu thp v mc tiu mong mun

2. Xc nh hng mc cn kim tra

3. Xc nh trnh t hng mc kim tra

4. Xc nh trng s ca tng hng mc da trn mc

quan trng

5. Xc nh dng ca phiu

6. p dng th v nh gi

7.p dng chnh thc

18

Cu hi v tr li

BIU PARETO

20

Mc ch p dng

S dung nguyen tac 20/80 trong san xuat, kinh

doanh, cuoc song

Chuyen van e ln thanh nhng van e nho

Xac nh cac yeu to quan trong nhat : so t nhng

quan trong

Ch ra ni can cai tien, khac phuc, tap trung no lc.

Giup s dung tot nhat nguon lc han che 21

Cch xy dng biu Pareto

Xc nh phng php v thi gian thu thp d liu theo

nguyn nhn hoc vn cn phn tch

Thu thp d liu

Sp xp d liu vo trong bng theo th t tng dn ca

tn sut ca tng loi nguyn nhn hoc loi vn .

Tnh phn trm v phn trm lu k ca tng loi so vi

tng tn sut ca ton b nguyn nhn/vn

V bng tay hoc s dng phn mm Excel/chuyn dng

22

Bang tong hp d lieu

Loai NN So lan % Luy ke%

Cha ao tao 65 54.17 54.17

May h 33 27.50 81.67

Sai P/ phap 12 10.0 91.67

Nguyen lieu

loi

8 6.67 98.33

Thieu kiem tra 1 0.83 99.17

Ban TP loi 1 0.83 100

Khac 0 0.0 100

23

Bieu o pareto

0

20

40

60

80

100

120

2p 1p 4p 3p 0p 7p 5p 6p

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

tan suat

luy ke

24

Bi tp thc hnh

25

Biu xng c

26

Mc ch p dng

Xac nh nguyen nhan goc re cua cac van e phc tap

Giup cho de dang trong cai tien san pham, he thong , dch vu.

Tm nguyen nhan cua s bien ong chat lng va moi quan he cua chung thong thng qua 6 van

e c ban: con ngi, MMTB, phng phap,

nguyen vat lieu, giam sat- o lng va moi

trng.

27

Cach xay dng

1) Xc nh vn (hu qu)

2) V Xng sng i din cho vn

3) Xc nh cc nguyn nhn chnh ca vn bng phng php ng no

4) Ni kt cc nguyn nhn chnh ti Xng sng bng nhng mui tn nghing

5) ng no tm nguyn nhn th ca nguyn nhn chnh

6) Ni kt cc nguyn nhn th ti nguyn nhn chnh

7) Lp li cc bc 5 v 6 cho cc nguyn nhn th tng t nh nguyn nhn chnh (thng t 4 n 5 cp)

8) Phn tch nh gi cc nguyn nhn chnh v th ( c th s dng biu pareto)

9) Quyt nh v c hnh ng thch hp 28

Bieu o xng ca nh hng nguyen nhan

Bc 1: Quyet nh tnh chat cua van e(hau qua)

Bc 2: Viet tnh chat va ve xng song cua bieu

o

Tnh chat (hau qua)

Xng song

29

Bieu o xng ca nh hng nguyen

nhan

Bc 3: Ve xng ln

Bc 4 : Ve xng va, nho, dam 30


Xng nho

Xng dam

31


Bc 5 kiem tra e khong bo sot nguyen nhan

Bc 6 xac nh va anh dau cac nguyen nhan quan

trong nhat

32


33


Bc 7: ien cac thong tin lien quan (ten

san pham, ten qua trnh, ten bo phan/

phong ban xay dng bieu o)

34


Cac loai tnh chat(hau qua): 1. Chat lng: kch thc,

trong lng, o tinh khiet,

t le khuyet tat, so loi, khieu

nai

2. Chi ph: t le li nhuan, lo,

chi ph vat lieu, chi ph, chi

ph nhan cong, so gi lam

viectac ong len san pham,

chi ph hoat ong..

3. Nang suat: thi gian san

xuat, san lng, t le hoat

ong 4. An toan: t le tai nan, so tai

nan, tan suat tai nan, sc

khoe

5. Tinh than lam viec: t le co

mat, so kien ngh cai tien, t

le tham d, t le vang mat

Cac nhom nguyen nhan anhhng

en tnh chat(hau qua): 4 en

8 nhom => hnh thanh xng

ln

1. 5M

Man (con ngi) Machine(may moc, thiet

b)

Method (phng phap, cong nghe, cach lam)

Material (vat lieu, chi tiet, thong tin)

Measurement (o lng, giam sat..)

2. 7 yeu to :

Jigs, tools (cong cu, o ga) Van chuyen 5M

35

Nhng ieu lu y

1. Lay y kien t nhieu ngi (4-10)

2. Lay tat ca cac nguyen nhan

3. Dien at cac tnh chat(hau qua) bang gia tr

4. Kiem tra, bo sung, cap nhat lai bieu o xng ca theo

thi gian

5. Ve bieu o xng ca cho 1 tnh chat(hau qua)

6. Xac nh va anh dau cac nguyen nhan quan trong:

Da tren thu thap d lieu

Thao luan da tren kinh nghiem va tri thc

Bieu quyet

7. Thu thap d lieu tai ni lam viec e xay dng bieu o

xng ca

36

TAM HIEN

1. Hien vat

2. Hien trng

3. Hien thc

37

Brain - storming

Moi ngi cung nhau lam viec =>phan ng day

chuyen s suy ngh => phat trien cac y kien tot

hn

38

4 Quy tac Brain-storming

1. Nghiem cam s ch trch & phe bnh

2. T do & linh hoat

3. So lng y kien quan trong hn noi dung

y kien

4. Theo uoi y kien cua ngi khac neu

thay co tia sang

39

Thc hien

1. Chon tnh chat cua van e can quan tam

2. Mi cac ca nhan co lien quan 4-10 ngi,

xac nh nhom trng & th ky

3. Chuan b cac card giay

4. Brain storming e a ra cac nguyen nhan anh hng en tnh chat

5. Phan loai cac card giay theo nhom

nguyen nhan cung loai => at ten, hnh

thanh xng va

40

Thc hien

6. Xac nh xng ln : nhom cac xng

va vao cung mot ho co lien quan => at

ten, hnh thanh xng ln (4 8 nhom)

7. Lap vao hnh xng song cua bieu o

8. Kiem tra con sot nguyen nhan khong

9. Xac nh cac nguyen nhan cho la quan

trong

10. ien cac thong tin lien quan

41

Lu y

1. Ky thuat xac nh xng nho : 5WHY

2. Tranh bieu o xng ca suy dinh dng

Hau qua

Vat lieu Cong nhan

May moc Phng phap

42

Bieu o xng ca nh hng phng phap

cai tien

Tnh chat : cach thc e cai tien van e nao o (at ben phai bieu o).

V du: cach thc nang cao doanh so ban hang

Xac nh cac bien phap can thiet e cai tien van e (xng ln, va, nho, dam)

43

Bieu o xng ca nh hng phng phap cai tien

How to

increase

sales

44

10 iem kiem tra bieu o xng ca

1. Co con sot nguyen nhan nao khong?

2. Cac nguyen nhan liet ke co u chi tiet e

co the hanh ong trong thc te khong?

3. Xng ln, va, nho, dam co c sap

xep 1 cach he thong?

4. Th t cua cac nguyen nhan co the truy

ngc xuoi c khong?

5. Co bat ky nguyen nhan nao khong lien

quan en tnh chat khong ?

45

10 iem kiem tra bieu o xng ca

6. Co xac nh th t u tien cac nguyen nhan

hay bien phap trong yeu khong?

7. Co nguyen nhan nao dien ta m ho khong?

8. Cac nguyen nhan e cap en tuoi, kch thc,

nhiet o, o am.co c liet ke cac gia tr khong?

9. Tnh chat co cu the e moi ngi de dang hieu

khong? co the thu thap d lieu e kiem chng

khong?

10. Co nhieu y kien cua nhieu ngi c liet ke

tren bieu o khong?

46

Biu kim sot Control Chart

47

02/10/2014 48 If you cant measure it you cant manage it !

School of Industrial Management



o chiu cao ca mt ngi, gi X l i lng th hin chiu cao ca ngi , X c l bin ngu nhin ?

m s ngi n ca hng trong ngy th 7, gi X l i lng th hin s ngi m c, X c l bin ngu nhin?

Bin ngu nhin ri rc (Discrete Random Variable)

Bin ngu nhin lin tc (Continuous Random Variable)

BIN NGU NHIN ?

C th ni l tt ca cc i lng m ta gp trong thc t u l cc bin ngu nhin v chng s phai thuc mt trong hai nhm ri rc hay lin tuc.



Quy lut phn phi xc sut ca bin ngu nhin l s tng ng gia cc gi tr c th c ca n v cc xc sut tng ng vi cc gi tr .

Bt k mt hnh thc no (m thng l th hoc bng s hay cng thc) biu din mi quan h gia cc gi tr c th c ca mt bin ngu nhin v xc sut tng ng ca chng th u c coi l hnh thc biu hin quy lut phn phi xc sut ca bin ngu nhin y.

Xc nh lut phn

phi ca bin ngu

nhin

Statistics

Statistics

POPULATION (N)

Parameters: 2

SAMPLE

Statistics: x, s, s2

Thng k suy din

n

Thng k m ta

Ly vi d

Cai chung ta rt mun bit, nhng ko th bit chinh xac

Cai chung ta c th bit

c lng

Tham s thng k

Statistics

Statistics

POPULATION (N)

Parameters: 2

SAMPLE Statistics: x, s, s2

n

Khong tin cy

-anh i bng n

-Khi n N: x s

c lng tham s thng k da trn c s nao ?

ng dng quy lut phn phi

x

x 1, x 2,

Vn : quy lut phn phi nao ?

n bao nhiu la u ? mong mun

chinh xac n u

Statistics

Statistics Qui lut phn phi thng gp: Phn phi Binh thng

Normal Distribution

Statistics

Statistics Lu y: Phn phi Binh thng Phn phi binh thng chun ha (Phn phi chun) Normal Distribution Standard Normal Distribution



Phai xac nh c ba thong so chnh * ng trung tam (x Center Line)

* ng gii han tren (UCL Upper Control Limit).

* ng gii han di (LCL Lower Control Limit).

Phan anh, mo ta c quy luat thay oi ngau nhien cua ai lng can

kiem soat

Cau truc cua mot

bieu o kiem soa t

Phan biet khuyet tat

& Phe pham



Upper Control

Limit

Lower

Control

Limit



m c, phn

loi. Ph phm, khuyt tt

o c, xu xng



S kin m c 1. Ph phm * Phn trm ph phm (p) * S lng ph phm (np) 2. Khuyt tt * Vng c hi ko i (c) * Vng c hi thay i (u)

Loai bieu o kiem soat X - R

Bieu o phan tch qua trnh: s dung e xac nh xem qua trnh co c kiem soat hay khong.

Bieu o kiem soat qua trnh: dung e xac nh tnh trang bat thng cua qua trnh .

84



R

oc hieu bieu o e anh gia tnh trang on nh:

Mot qua trnh trong trang thai on nh hay trong tnh

trang kiem soat : neu cac iem d lieu khong nam

ngoai cac gii han kiem soat hoac khong tao ra xu

hng. Cac iem sau ay cung ch ra qua trnh c

kiem soat:

25 hoac hn cac iem d lieu nam trong gii han kiem soat .

Trong so 35 iem d lieu ch co 1 iem d lieu nam ngoai ng gii han kiem soat ma qua iem nay cung

khong xac nh c co iem bat thng.

Trong so 100 iem d lieu , ch co mot hoac 2 iem d lieu nam ngoai gii han kiem soat ma qua iem nay

cung khong xac nh c co iem bat thng

97

oc hieu bieu o e anh gia tnh trang on nh:

Mot qua trnh trong trang thai khong on nh ( bat

thng) hay khong trong tnh trang kiem soat trong

nhng trng hp sau:

Cac iem d lieu hoac mot so iem d lieu nam

ngoai ( tren hoac di ) ng gii han kiem

soat.

Mac du cac iem d lieu nam trong gii han

kiem soat, no ch ra mot trong cac xu hng sau:

98

Cac trang thai khong on nh

Dang mot ben ng tam

a) 7 iem lien tiep mot ben ng tam

b) 10 trong 11 iem lien tiep

c) 12 trong 14 iem lien tiep

d) 14 trong 17 iem lien tiep

e) 17 trong 20 iem lien tiep

99


Dang xu hng:

06 hoac 07 iem lien tiep, tiep tuc tang hay giam

100


4/ Dang chu ky

101


Dang ke can cac ng kiem soat:

2 trong 3 iem

3 trong 07 iem

4 trong 10 iem

102


Dang ke can ng trung tam

103

p dng biu kim sot 1/ Chn cc ch tiu cht lng quan trng cn kim sot,

ch tiu phi d o cho php can thip kp thi vo qa trnh

sn xut

2/ Lp biu kim sot phn tch

3/ Xy dng mt biu kim sot kim sot qu trnh

4/ Kim sot qu trnh sn xut

5/ Tnh ton li cc ng kim sot khi c s thay i :

My mc

Qui trnh cng ngh

Ngun nguyn vt liu 104

Biu phn tn

105

Bieu o phan tan la g?

Xet 2 loai ac tnh d lieu X va Y

1. Neu X bien oi => Y bien oi : s tng

quan

2. Phng phap th nghiem thong ke e

xac nh s hien hu cua moi quan he X

va Y: phan tch s tng quan

106

Cach thc s dung bieu o phan tan

1. Xem xet

lieu co moi

quan he

khong?

107

Cach thc s dung bieu o phan

tan

2. Co nhng ket qua bat thng khong?

108

Cach thc s dung bieu o phan

tan

3. Xem xet co can phan vung so lieu khong?

109

Xay dng bieu o phan tan

V du : Kiem tra moi quan he gia nhiet o cuon day va nhiet o be mat cua motor

110

1. Chuan b bieu o phan tan

Bc 1 : thu thap d lieu tng quan X & Y

So cap d lieu > 30

Bc 2 : xac nh Xmax

, Xmin

, Ymax

, Ymin

Xmax

= 44,5 Xmin

= 30,6 => Xmax

Xmin

= 13,9

Ymax

= 26,9 Ymin

= 15,9 => Ymax

Ymin

= 11,0

Xac nh n v cua truc X & truc Y

111


Bc 3 : a cac cap

so lieu len o th

1 iem

2 iem trung nhau

3 iem trung nhau

c

c

112


Bc 4 : ien cac thong tin can thiet len bieu o

114

2. Kiem tra moi tng quan

Bc 1 : ve ng trung v ng

So d lieu n le : ng trung v i qua iem

gia cua cac iem

So d lieu n chan : ng trung v i qua

trung iem cua 2 iem nam gia cac iem

Bc 2 : ve ng trung v ngang

115


116


Bc 3 : em cac so iem nam cac o vuong khac nhau

117


Bc 4 : tnh n+ va n

-

v du : n+ = n

1 + n

3 = 18+18= 36

n- = n

2 + n

4 = 7 + 7 = 14

So sanh n+ va n

- xac nh n

min

Neu n

+ n

- th n

min = n

-

n

min = 14

118


Bc 5 : xac nh s tng quan

S dung bang dau hieu tng quan

Neu nmin

< gia tr trong bang dau hieu tng quan

=> ket luan : co moi tng quan X & Y

Neu nmin

> gia tr trong bang dau hieu tng quan

=> ket luan : khong co moi tng quan X & Y

V du : nmin

= 14 < gia tr trong bang la 15 => X va Y co

moi tng quan vi mc y ngha 0,01 (1%)

119

Bang dau hieu tng quan

120

Cc c tnh tng quan

1.Tng quan gia nguyn nhn v kt qa - v d:

tinh khit ca nguyn vt liu v c tnh ca sn

phm

Hm lng Ag v dn in

Khong cch v s lng cuc gi gim

S bo gi v t l hp ng

121

Cc c tnh tng quan

2. Tng quan gia kt qa v kt qa v d :

bn ko v cng ca thp

Sn lng v t l khuyt tt

Chiu cao v cn nng ca con ngi

S hp ng v doanh thu

S khch hng v t l khiu ni

122

Cc c tnh tng quan

3.Tng quan gia nguyn nhn v nguyn nhn :

S tch cc ca hc vin v s tch cc ca gio

vin

Nhit nung v thi gian nung

Tng s thnh phn cht A v thnh phn cht B

trong nguyn liu

Ap lc cn v thi gian cn trong qu trnh cn

123

Biu phn b

124

MC CH P DNG

Biu din lng ln gi tr d liu di dng

biu quan h n gin

Cho bit mi lin quan ca tn sut xut hin

D dng nhn thy s phn b ca d liu

Nhn ra c bin ng trong d liu khng

D bo tng lai da trn d liu

125

Biu phn b

GHD GHT

o rong lp

Bien gii lp

lp

TAN SUAT

h

Gia tr trung bnh 126

1/ Tnh so lp : k>5; k

Cach xay dng

4/ Tnh gia tr trong bien gii lp au tien

[ Xmin h/2 ; Xmin + h/2]

5/ Xac nh cac gia tr bien gii lp con lai

128

Cach xay dng

6/ em tan suat xuat hien

TT BIEN GII LP GIA TR

TRUNG TAM

TAN SUAT f d f.d f.d2

1

2

3

4

5

6

7

8

9

10

xmin h/2 xmin + h/2

.

xmin

X0 ...

..

fmax

-4

-3

-2

-1

0

1

2

3

4

5

0

0

129

1

/22

0

N

NfdfdhS

hN

fdXX

130

V d

B d liu khch hng n mua Pizza

KH1 khng mua; KH2 mua 2. 0 2 1 2 2 4 1 3 1 2 1 2 2 4 3 4 1 4 3 2 2 3 2 1 2 2 1 2 2 1 4 2 2 1 2 1 2 2 1

2 1 2 1 2 1 2 1 2 1 2 2 2 1 2 1 2 1 1 2 2 2 3 1 4 2 2 3 2 2 2 1 2 3 2 2 4 2

2 4 4 1 2 2 2 3 2 2 1 2 2 4 2 1 2 4 2 1 7 2 1 2 2 3 1 2 1 1 2 1 2 2 2 1 2 2

1 2 1 2 2 2 4 2 4

V d: Ca hng Pizza

Mean = 2.032258

Max = 7

Min = 0

Range = 7

Vi 7 ct th rng mi ct

W= Range/Columns=7/7=1

33

65

812

0 0 1

0

10

20

30

40

50

60

70

1 2 3 4 5 6 7

Slices of Pizza

Histogram

V d: Ca hng Pizza

Histogram

Nhn xt:

n hng 2 phn pizza l thng thng nht

Phn b bn hng hiu qu cho d bo ngy sau

Nu bn l nh qun l bn s ci thin g t thng tin ny

DANG BIEU O

135

DANG BIEU O

Phn b u Phn b lch tri Phn b lch phi

Phn b hai nh Phn b nhiu nh

136

OC BIEU O

Hnh

so

loai Giai thch dang bieu o iem can kiem tra

a Dang

chung

Can oi, tan suat cao nhat trung

tam, tan suat giam dan ve 2

canh,o rong bieu o nho hn gii

han dung sai

o th on nh

b Dang lc o th dang rang lc, tan suat

cao, thap xen lan nhau

Tnh toan sai khi lam

tron so/ xu hng cua

ngi o

c Nghieng

trai hoac

phai

Trung tam phan bo lech trai hoac

phai

Sai so he thong hoac

cac thanh phan khong

ong nhat

d Vach nui o th khong can xng, co vach

nui dng ng ben trai hoac ben

phai

a loai bo nhng san

pham khong at khoi lo

hang, hoac co xu hng

sai lech nao o cua

ngi o/hoac thiet b

o

137

OC BIEU O

Hnh

so

loai Giai thch dang bieu o iem can kiem tra

e Dang bnh nguyen Tan suat cua moi lp gan

bang nhau

Tron lan nhieu phan bo

khac nhau, can phan

vung so lieu theo 5W1H

f Dang hai nh Tan suat trung tam

thap, o th co 2 nh

2 phan bo khac nhau b

tron lan, can phan vung

so lieu theo 5W1H

g Dang ao co lap Ben trai hoac phai cua

bieu o, co ao nho nam

co lap

Co s tron lan 1 so

lng nho sp khong at

hoac co s bat thng

trong qua trnh san

xuat/ hoac sai loi trong

qua trnh o

138

Nang lc qua trnh

Nang lc qua trnh (process capability): kha

nang cua mot qua trnh e san xuat ra cac

san pham co dung sai thong so ky thuat mong

muon hay t le khuyet tat cho phep (dung sai

nam trong khoang cho trc theo thiet ke)

trong mot giai oan lau dai nao o.

139

Benefits of 6approach

-level Defect rate (ppm)

Costs of poor quality Status of the

company

6 3.4 < 10% of turnover World class

5 233 10-15% of turnover

4 6210 15-20% of turnover Current standard

3 66807 20-30% of turnover

2 308537 30-40% of turnover Bankruptcy

Financial Aspects



nh gia nha cung cp

Ch so kha nang qua trnh CP - C

pk

1. Tieu chuan 2 pha GHT&GHD

2/

2/

61

6

LCLUCL

XLCLUCLK

LCLUCLKC

LCLUCLC

PK

P

o lch chuan

K mc o nghieng cua bieu o

151


pk

2. Tieu chuan co gii han 1pha GHT hoac GHD

S

GHDXC

S

XGHTC

P

P

3

3

152

S dung CP khi bieu o co trung tam phan

bo gan trung tam cua gii han dung sai

GHT&GHD

S dung Cpk

khi bieu o co trung tam phan

bo lech khoi trung tam cua gii han dung

sai GHT&GHD


pk

153

Chuan mc anh gia kha nang cua qua trnh

1. CP

>= 1,67 qua trnh tha kha nang, on nh, tm cach

kiem soat n gian hn, chi ph hieu qua hn

2. 1,67 > Cp>= 1,33 qua trnh co u kha nang, tnh huong

ly tng, duy tr

3. 1,33 > Cp >= 1,00 qua trnh co dau hieu khong u kha

nang, phai thc hien kiem soat chat che qua trnh khi

Cp tien gan ti 1, khuyet tat se bat au xay ra can x

ly

4. 1,00 > Cp >= 0,67 qua trnh khong u kha nang, khuyet

tat a xay ra, phai cai tien qua trnh

5. 0,67 > Cp qua trnh qua kem, chat lng hoan toan

khong thoa man, phai cai tien qua trnh, ieu tra

nguyen nhan, a ra bien phap khan cap, co the phai

xem xet lai gii han dung sai cua tieu chuan khi can

thiet

154

Cong thc ,

1

/1

2

1

2

1

N

NXX

N

X

X

N

i

N

i

ii

N

i

i

X

155

Biu phn vng 5W1H

156

Mc ch ng dng

Cng c kt hp vi cc cng c thng k khc

tng kh nng phn tch d liu

Dng phn tch d liu. D liu ban u c

th xut pht t nhiu ngun, nhiu loi b trn

chung nh ca, ngy trong tun nn khng th

hiu c ngha.

Tch ring cc d liu khc nhau theo yu cu

phn tch 157

Cch p dng

Trc khi thu thp d liu phn tch cc d liu t nhiu ngun khc nhau c th nh hng n kt qu Thit lp vic thu thp d liu vi cc thng tin mong mun

Khi v biu ( phn tn, phn b, kim sot) dng mu sc, cc mark khc nhau biu th cc d liu t cc ngun khc nhau (phng php phn tng)

Phn tch cc nhm ph c phn tng ring r.

158

Biu phn vng 5W1H

159

Bieu o phan vung 5W1H

Sau khi thu thp s liu v v biu => phn tch cho thy kt qu tt ( nhng kt qu ny c th c sai li) hoc kh xc nh c c th v tr hoc vn cn ci tin, cn :

Phn vng theo 5W1H => xc nh c chnh xc vn cn ci tin:

Who : ai

What : ci g

When : khi no, thi gian no

Where : ni chn, b phn, khu vc

Why : ti sao

How : cch thc, phng php 160

Biu phn vng 5W1H

D lieu thng c phan tang theo:

May moc thiet b

Ca

Bo phan

Nguyen lieu

Nha cung ng

Ngay trong tuan

Thi gian trong ngay

San pham

161

Ky thuat phan tch d liu

3 kha canh can phan tch:

Mc o

Xu hng

Dao ong

162

Mc o

So sanh ket qua thc te cua d lieu vi :

Muc tieu

Ke hoach

nh mc

Ket qua cung ky thi gian trc

oi thu canh tranh

Chuan oi sanh(benchmarking)

163

Khong at

Mc o

at Muc tieu/ke hoach/ nh mc/

Ket qua cung ky thi gian trc/

oi thu canh tranh/chuan oi sanh

164

Xu hng

Xu hng

xau tang

dan hoac

giam dan

165

o dao ong

Dao ong qua

ln?

166

03 04 05 07 08 09 1/06 2/06 3/06. 12/06

LI NHUAN

THI GIAN

THC TE

MUC TIEU

OI THU CANH TRANH

So lieu qua kh, hien tai, tng lai

167

Phan vung Why - How

WHY

Tai sao

HOW

Bien phap

..

..

..

..

..

..

..

..

Bien phap

tot

Duy tr

168

Q&A

169

Documents

chuong 3 SPC7tools.pdf