Laborator 1 - CAF Controlul statistic de receptie al componentelor electronice Toie Mihai Grupa 441 C
Scopul lucrării: Studiul asupra calităţii produselor, ţinând c ont de standardul MIL-STD 105E: „Sampling procedures and tables for inspection by attributes”, şi STAS 3160-84, în vederea efectuării controlului controlului statistic de recepţie, prin atribute, al componentelor electronice. Desfasurarea lucrării : 1) Daţi exemple de defecte: - critice, majore, majore, minore (tip A şi B) pentru un televizor şi o sursă de alimentare; Televizor:
DEFECT CRITIC DEFECT MAJOR DEFECT MINOR TIP A DEFECT MINOR TIP B
Tub Ars Ecran zgâriat Butoane care se mișcă din suport Carcasă zgâriată
DEFECT CRITIC DEFECT MAJOR DEFECT MINOR TIP A DEFECT MINOR TIP B
Capete de alimentare îndoile Protectie proastă la supratensiune Fluctuatii mici ale tensiunii Nefunctionarea unui dn butoane
Sursa de alimentare:
2) Determinaţi corelaţia nivel de control - risc - efectivul eşantionului; Alcătuiţi planurile de control pentru un lot de componente electronice de volum N precizat mai jos pentru cele 4 categorii de defecte, în ipotezele nivel de control general (N c = II) şi severitate normală. N
AQL %
100 F
0.25 0.4 2.5 6.5 0.25 0.4 2.5 6.5 0.25 0.4 2.5 6.5 0.25 0.4 2.5 6.5 0.25 0.4 2.5 6.5
1000 J
15000 M
100000 N
500000 P
Sondaj simplu n A 50 0 32 0 20 0 20 3 50 0 125 1 80 5 80 10 315 2 315 3 315 14 200 21 500 3 500 5 500 21 200 21 800 5 800 7 500 21 200 21
Sondaj dublu R 1 1 1 4 1 2 6 11 3 4 15 22 4 6 22 22 6 8 22 22
n 50 32 13 13 50 80 50 50 200 200 200 125 315 315 315 125 500 500 315 125
A1 0 0 0 1 0 0 2 5 0 1 7 11 1 2 11 11 2 3 11 11
R1 1 1 2 4 1 2 5 9 3 4 11 16 4 5 16 16 5 7 16 16
A2 0 0 1 4 0 1 6 12 3 4 18 26 4 6 26 26 6 8 26 26
Sondaj multiplu R2 1 1 2 5 1 2 7 13 4 5 19 27 5 7 27 27 7 9 27 27
n 50 32 5 5 50 32 20 20 80 80 80 50 125 125 125 50 200 200 125 50
A1 0 0 -1 -1 0 -1 -1 0 -1 -1 1 2 -1 -1 2 2 -1 0 2 2
R1 1 1 2 3 1 2 4 5 2 3 7 9 3 4 9 9 4 4 9 9
A2 0 0 -1 0 0 -1 1 3 0 0 4 7 0 1 7 7 1 1 7 7
R2 1 1 2 3 1 2 5 8 3 3 10 14 3 5 14 14 5 6 14 14
A3 0 0 0 1 0 0 2 6 0 1 8 13 1 2 13 13 2 3 13 13
R3 1 1 2 4 1 2 6 10 3 4 13 19 4 6 19 19 6 8 19 19
A4 0 0 0 2 0 0 3 8 1 2 12 19 2 3 19 19 3 5 19 19
R4 1 1 3 5 1 3 7 13 4 5 17 25 5 7 25 25 7 10 25 25
A5 0 0 1 3 0 1 5 11 2 3 17 25 3 5 25 25 5 7 25 25
R5 1 1 3 6 1 3 8 15 4 6 20 29 6 8 29 29 8 11 29 29
A6 0 0 1 4 0 1 7 14 3 4 21 31 4 7 31 31 7 10 31 31
R6 1 1 3 6 1 3 9 17 5 6 23 33 6 9 33 33 9 12 33 33
A7 0 0 2 6 0 2 9 18 4 6 25 37 6 9 37 37 9 13 37 37
R7 1 1 3 7 1 3 10 19 5 7 26 38 7 10 38 38 10 14 38 38
AQL Critic = 0.25 Major =0.4 Minor tip A = 2.5 Minor tip B =6.5
P1=0.99 0.16 0.36 2,51
P2=0.95 0.27 0.52 2,98
P3=0.9 0.35 0.63 3,25
P4=0.75 0.51 0.84 3,74
P5=0.5 0.73 1.13 4,33
P6=0.25 1.02 1.48 4,99
P7=0.1 1.34 1,86 5,64
P8=0.05 1.55 2,1 6,05
P9=0.01 2.01 2,62 6,87
6,29
7,45
8,12
9,34
10,8
12,5
14,1
15,1
17,2
Pacc =f(p) 20 18 16 14 12 10 8 6 4 2 0 0.01
0.05
Critic=0.25
0.1
0.25
Major=0.4
0.5
0.75
Minor tip A=2.5
0.9
0.95
0.99
Minor tip B =6.5
4. Se consideră un plan de control de calitate de tipul selecţiei simple cu parametrii: N=100.000; AQL=1,5%; nivelul de control Nc
poate avea toate cele 7 valori (S 1....S4, I...III). Să se arate care dintre aceste niveluri de control este mai sever. Nc S1 S2 S3 S4 I II III
Litera
p1
p2
p3
p4
p5
p6
p7
p8
p9
0,99
0,95
0,90
0,75
0,50
0,25
0,10
0,05
0,01
D
0,130
0,640
1,310
3,530
8,300
15,900
25,000
31,200
43,200
E
0,130
0,640
1,310
3,530
8,300
15,900
25,000
31,200
43,200
G
0,470
1,130
1,670
3,010
5,190
8,190
11,600
14,000
19,000
J
1,050
1,730
2,200
3,180
4,570
6,310
8,160
9,390
12,000
L
1,450
1,990
2,330
2,980
3,840
4,840
5,890
6,570
8,000
N
1,500 1,570
1,850 1,860
2,060 2,030
2,450 2,340
2,930 2,710
3,480 3,120
4,030 3,520
4,380 3,780
5,090 4,290
P
În urma graficului, se observă că nivelul de control general, III , este cel mai sever. Zona sa de acceptare este cea mai mică, în comparație cu celelalte nivele de control. Acesta oferă deci protecție mai ridicată. La cealaltă extremă, se află nivelul special S1 ( în a cest caz coincide cu S2) , care oferă cea mai slabă protecție.
5. Se va accesa www.sqconline.com Standardul MIL-STD 105E: Proceduri de prelevare a probelor şi tabele pentru inspecţie prin atribute. Se vor introduce parametri doriţi în formularul din pagina web şi se vor nota rezultatele şi graficele realizate.
Military Standard 105E (ANSI/ASQC Z1.4, ISO 2859) Tables For a lot of 281 to 500 items, AQL=1%, and inspection level II, the normal inspection plans are:
The Single sampling procedure is:
Sample 50* items. If the number of non-conforming items is 1 or less --> accept the lot. 2 or more --> reject the lot. The Double sampling procedure is:
Step 1:
Sample 32* items. If the number of non-conforming items is 0 --> accept the lot. 2 or more --> reject the lot. Otherwise, continue to step 2.
Step 2:
Sample 32* additional items. If the total number of non-conforming items is 1 or less --> accept the lot. 2 or more --> reject the lot.
Important: This sampling plan will yield valid results only if applied with the Military Standard 105E switching rules. * Note: If the sample size(s) exceeds the lot size, apply 100% sampling of the lot.
OC Curve
The OC curve describes the probability of accepting a lot, OC(p), as a function of the proportion nonconforming (p), for the single and double sampling plans described above. ASN Curve
The ASN curve describes the average sample size, when employing double sampling, as a function of the proportion of non-conforming items (p). Quality means doing it right when no one is looking.
— Henry Ford
Military Standard 105E (ANSI/ASQC Z1.4, ISO 2859) Tables For a lot of 35001 to 150000 items, AQL=0.025%, and inspection level II, the normal inspection plans are:
The Single sampling procedure is:
Sample 500* items. If the number of non-conforming items is 0 --> accept the lot. 1 or more --> reject the lot. In this case, consider the Single sampling plan, or use the following plan:
The Double sampling procedure is:
Step 1:
Sample 1250* items. If the number of non-conforming items is 0 --> accept the lot. 2 or more --> reject the lot. Otherwise, continue to step 2.
Step 2:
Sample 1250* additional items. If the total number of non-conforming items is 1 or less --> accept the lot. 2 or more --> reject the lot.
Important: This sampling plan will yield valid results only if applied with the Military Standard 105E switching rules. * Note: If the sample size(s) exceeds the lot size, apply 100% sampling of the lot.
OC Curve
The OC curve describes the probability of accepting a lot, OC(p), as a function of the proportion nonconforming (p), for the single and double sampling plans described above. ASN Curve
The ASN curve describes the average sample size, when employing double sampling, as a function of the proportion of non-conforming items (p). It is not enough to do your best; you must know what to do, and then do your best.
— W. Edwards Deming
