Final Exam ESE 405/505 December 15,2008 - Washington … ·  · 2008-12-07Final Exam ESE 405/505...

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Final Exam ESE 405/505 December 15,2008 Your Name: So\V\-t\OfhS Your ID #: There are 4 problems in this examination.

Transcript of Final Exam ESE 405/505 December 15,2008 - Washington … ·  · 2008-12-07Final Exam ESE 405/505...

Final Exam ESE 405/505

December 15,2008

Your Name: So\V\-t\OfhS

Your ID #:

There are 4 problems in this examination.

1.(30 pts) Consider the following 25 samples.

Sample XlXlXl

10.06290.06360.0640

20.06300.06310.0622

30.06280.06310.0633

40.06340.06300.0631

50.06190.06280.0630

60.06130.06290.0634

70.06300.06390.0625

80.06280.06270.0622

90.06230.06260.0633

100.06310.06310.0633

110.06350.06300.0638

120.06230.06300.0630

130.06350.06310.0630

140.06450.06400.0631

150.06190.06440.0632

160.06310.06270.0630

170.06160.06230.0631

180.06300.06300.0626

190.06360.06310.0629

200.06400.06350.0629

210.06280.06250.0616

220.06150.06250.0619

230.06300.06320.0630

240.06350.06290.0635

250.06230.06290.0630

(a) Determine X and R charts using all sample points. You should see that bothX and R charts out-of-control.

(b) Remove samples 14, 15, and 22. (The remaining sample points are within the

UCL and LCL of the new X and R charts formed without sample points 14, 15,

and 22.) Using the remaining samples, estimate the standard deviation, ux.

(c) Determine the 6-(J limit using the result of part (b).(d) If the specifications are at 0.0630 ± 0.0015, determine the value of the process

capability ratio, Cpo

(This page is left blank for your work.)

CC\')

0.0640,--'-·_-

.•I UC L;O.063893

~ 0.0635

01III

~ 0.0630-1\ ~\1\/\/ "'.../\r\. !X;0.062952l ~ 0.0625

O.06:W~

."yj)I LCL=0.062011

,

.,.. . ..,.,2

468101214161820

Sampl~,

O.0024-!

WIu c L=O~00;2368.•..:

'" 0.0018'" ... .'!II:i 0.0012 I ___/"\A· I\ I\/ ,'" I R=O.OOO92

E . ,~ 0.0006

o.oo~~

--. y.•..•. VI LCi.=O,

,•,........2

4681012' 141618202224

Sample

/\Ux -=- ~I d~-

( Y\ -::;. 3 ~ Q.

o I 0 00 <32-3, / \ \ 6 <1'3 -:::::. O. 00 t) <t t) 6

W i\-ho--t- S<>WI pIE'> 14- 10;- <L. 22. ::: 0,000 i'2?, )) ,

(()/\

X + 30X :::

::::[0, o6t4-Q 2 ) 0 I o6lf4--0 (:) J

ex w \4 0 J- ~c.lV' p\-e .s. 14- i (S:-) ~ 2-.2- -:.:: 0 I 0628 ~-)

Cd) 0lD030~ -..... ~---

b ~ 0; 0()0 l;.l!-'/)

2.(20 pts) Consider the following 16 samples. Each sample consists of 4 inspections.Determine a control chart for nonconformities per unit. Is the process in control?

Sample Number ofNonconformities1

1

23

32

41

50

62

71

85

92

101

11

012

213

1

141

152

163

1.4

Y\=- 4 m ~·I .()

CL =- AA -=- L M ~IW\ =f:!- X.L/f\ "') 1'tV\

-=- (;2l ( 4 )/ I 6 -=- 0 I 4-~L

(ACL::. AJ: -+ ~ fM: (n "",OIv.:n+3~1.

-= I \~96

I ~ ~ JOI;,~L-(L ~ M _ S ~ M(V\ =- 0\ 4-11.- '3 '+

.::-0 \~~~ ~ 0

UCl=L396

1.2

it:!

:5 1.0•..

l. 0.8.•..c.::I

8 0.6.sl

~ 0.4~ .

0.2

0.0

U=0.422

LCL=O

2 4 8 . 10

SafT1)1e

12 14 16

----- -- --

3.(20 pts) Consider a c-chart for 6-(J control corresponding to 16 nonconformities among30 units inspected.

(a) Determine the a-risk based on this chart.(b) Determine the fi-risk if the average number of defects is actually 2 (i.e., c=2.0).

c~) c ~ 16/30 -=- OIS-~3 ) Do: l6UCL -=- C 't- "3 ~ ~ 2- \ 123>

L C L -:::: C - :5 JC -:::- \ \ is "5 7 -"/ 0

rA -=:.- \7K)~ D< Lc L\ C'. \ -r PJ-of D >vCLI c ')

~ -==- ?r-o~ t> < 0 \ 0 IS-is ~ -t PV6t D > 2. \ 7 2.3 \ o· ~~3 ~

o t\J-. :::.. 0, 0 I 7

c b') r::.. f vot D < veL I c.. \

~ = f' hJ~ D < ~, 1"L \ 2. ")

--

PVO( () <. LCL{ c \

f\-o f D ~ 0 \ ~ '\

4.(30 pts) A process is in statistically control with x = 39.7 and Ii = 2.5. The controlchart uses a sample size of n = 2. Specifications are at 40 ± 5. The quality characteristicis normally distributed.

(a) Determine the potential capability of the process, Cpo

(b) Determine the actual capability of the process, i.e., Cpk = min( Cpu, Cp1 ).

(c) Determine how much improvement could be made in the value of the fractionnonconforming, i.e., p, if the mean could be centered at the nominal value .

f\ -=- 2. )

......

X=-39,7 R=o2,t;)

~ -()~ ~ RId 'L -:::.')~,~ II, l2.8- =. '2.:2.u;

4-(;- - 3 S-

6 (2.. . .Z-/ t )1\

--ft.s - '3q I 1Cb"

C~V\ -:::.

(A~L- Y-

-:: O. 8-D

. ) -...-~ - -3 (2.2/6)3D;

/\ ~ - lS~ _3,'1 \ -, -1S--C p~ -::: ::..0,.130- 3[2,2..1')f\ (' 1\ C PK":-' ~;yj; nee pv I C P..t ) -=- 0 I I I

pvv ~ X < L ~ L '\ -t P VQ ~ x. "/ V\ S L ~

- pv-o ~ l- < L~Li ")+ p"", ~ to 7 ~S:';-Y: ')(; X lIx

- pt.-() ~ ~. < ."~S--]~17_~ -;- PYt? f ~ ....,.t-I-~- 3~~1 "'\2.,2..\6 2.\2..I~

b, D ~~ 34- <6

1\if) P