ASSQC

Session 1,2 What is quality Quality related terms & Definitions Ref: Managing Quality in the apparel Industry-Mehta and Bharadwaj:Chapter 1

Quality Assurance for Textiles and Apparel-Sara J. Kadolph ;Chapter 2

How do we define quality?

Traditional definitions of Quality • Fitness for use- Joseph Juran

• Conformance to requirementsPhilip Crosby

Quality defined • "Quality" is defined as that combination of design and properties of materials of a product which are needed for the intended end use and level of the market in which it is sold. • "Requisite Quality" is defined as the design and composition of a product, which has been thoroughly proved by adequate development work, in order to establish its reliability under the conditions to which it will be subjected in use and to avoid producing too high a grade of product for the intended market.

Quality Defined • A holistic definition of Quality can be – • Quality is a dynamic state associated with products, services, people ,processes and environments that meets or exceeds expectations (Goetsch and Davis 1994) • Can have a (Garvin) – – – –

Product perspective, Producer's perspective or Consumer's perspective Value perspective

product • In this view, quality is determined as a precise and measurable variable and difference in quality reflects differences in the quality of some ingredient or attitude seen to be possessed by a product. In this view quality and quantity has direct relation

customer • In this view, definitions are based on the premise that solely the user determined quality. Individual customers are assumed to have different wants or needs and goods that best satisfy the preference are the one they regarded, as having the highest perceived quality. Quality is fitness for use that this view also reflects a highly personalized and subjective view

manufacturing • This view focuses on manufacturing and engineering practices. It emphasis conformance to specified requirements. The higher the degree that meets specified requirements the higher the quality. This view seeks to ensure that the deviations from standards set design specifications are minimized. • To achieve the quality of conformance means improving in the design of the • •Equipment •Materials •Supervision •Control •Training

Value based • The base for this view is physiological understanding of the meaning of value. Consequently, customers have been conditioned to accept that the quality of product is determined by the price. There fore price and quality have a direct relation ship

Dimensions of quality • 1. 2. 3. 4. 5. 6. 7. 8.

Positioning of a company based on Garvin`s Model Performance Features Reliability Conformance Durability Serviceability Aesthetics Perceived quality

Dimensions of quality •1.Performance: (will the product do the intended (planed or proposed) job). Potential costumer usually evaluate a product to determine if it will perform certain specific functions and determine how well it perform them. •Example: producing document case leather bag, for what purpose does is bag produced, does the bag has multi function pocket?

2.Reliability: (how often does the product fail?) different products may need repair over their service life. The leather machineries should be also reliable so as to increase productivity •Example: when we produce the leather garment, it needs higher attention during stitching. Because the nature of the needle is like cuter edge type and stitch the component by cutting the part. So re stitching is not done, means no repair and only rejection.

Dimensions of quality 3.Durability: (how long does the product last?).This is the effective service life of the product customer obviously want products that performed satisfactorily over a long period of time. 4.Serviceability: (how easy is it to repair the product?). There are many industries where the customer’s view of quality is directly influenced by how quickly and economically a repair or routine maintenance activity can be accomplished. Example: planned maintenance of stitching machine. 5. Aesthetics: what does the product look like?). this is the visual appeal of the product, often taking into account factors such as style, color, shape, packaging alternatives and other sensory features. 6.Features :( what does the product do? ). Usually customer associate high quality with products that have added features: that is, those that has features beyond the basic performance of the competition

Helena M de Klerk and Stephina J Lubbe;Journal of Family Ecology and Consumer Sciences, Vol 32, 2004

Quality in the garment Industry • • • •

Still at inspection level – AQL Quality is inspected into the product. A few firms are attempting SPC. Still a long way to go to finally reach global quality standards

Why improve quality? • • • •

FOB is getting lesser Delivery time is getting lesser Costs are increasing. We need to keep providing better service to hold the buyers’ attention. – Provide indisputable quality – Provide indisputable quality at better costs.

Importance of QUALITY • The consumer quality expectations have gone up • Consumer is too busy to come back and complain • Consumer is not interested to take special care of the product • Consumer spending on apparel has reduced • Stringent consumer protection laws • Stores cannot afford a dissatisfied customer • Working with non-quality vendors is costly

Terms related to quality • Quality Assurance – 1. All those planned and systematic actions necessary to provide adequate confidence that a product or service will satisfy given requirements for quality. 2. The establishment and maintenance of ALL activities and functions concerned with the attainment of requisite quality"

Terms related to quality • Quality Control – 1.The operational techniques and the activities used to fulfill the requirements of quality is called quality control. It is the regulatory process through which we measure actual quality performance, compare it with quality goals and act on the difference. 2. The systems required for programming and coordinating the efforts of the various groups in an organization to maintain the requisite quality" As such Quality Control is seen as the agent of Quality Assurance or Total Quality Control

Quality related terms • Quality Management -That aspect of the overall management function that determines and implements the quality policy. • Quality System -The organizational structure, responsibilities, procedures, processes and resources for implementing quality management

Session 3,4 What is Quality Standard and Quality Grade Different textile and apparel standards Ref:Managing Quality in the apparel IndustryMehta and Bharadwaj-Chapter 14 Quality Assurance for Textiles and ApparelSara J. Kadolph-Chapter 3

Standards • Standard– a set of characteristics or procedures that provide a basis for resource and production decisions. • Standardization - is the process of developing and applying rules for a consistent and uniform approach to a specific activity for the benefit and with the cooperation of all concerned.

Standards-uses 1. Used to define weights and measures 2. Used to set forth practices and expectations in the field. 3. Used to describe the characteristics of a product in a precise and consistent fashion. 4. Used to describe a minimum level of performance and safety. 5. Used to convey information about a product or material in a consistent manner. 6. Enhances efficiency –standardization of parts, processes and products enables economies of scale in production. 7. Standardization leads to enhanced competition.

Types/Levels of standards • Company Standards-describe general characteristics or features of a product or service or they describe a required level of performance. • Useful for the design, purchase, development and production departments as they may be developed by the company itself or adopt other organization's standards for its specific purpose.

Types/Levels of standards • Industry standards – reflect consensus among companies in an industry or among individual members of a profession. • Developed by trade associations or professional bodies.

Levels/Types of standards • Voluntary standards- allows individuals or companies to determine on their own whether to adopt a standard. • ASTM –one of the largest voluntary standards development system in the world • Mandatory standards – adoption is required by law or regulation. Mostly related to health or safety issues.

Comparison between Various U.S. Drawstring Standards

• Neck area Prohibitions• ASTM Standard (F1816-97) –a Voluntary national standard: • No drawstrings in the hood and neck area of certain children’s clothing. Only children’s upper outerwear. Sizes 2t to 12. • Wisconsin Law(ATCP 139)-a State regulation: • No drawstrings in the hood and neck area of all children’s clothing. All children’s clothing. Sizes 0 to 16.

Levels/Types of standards • International standards-standards are used internationally to facilitate trade and technology transfer among nations • Goal is to – Enhance product quality and reliability at reasonable prices – Improve health and safety and environmental protection – Reduce hazards – Produce greater compatibility of goods and services – Simplify and improve product and service usability – Increase distribution efficiency

Different standardizing bodies ( refer Sara Kadolph; Mehta and Bhardwaj) • ASQC- American Society for Quality control • ASQC_TNT- American society for quality control-textiles and needle trade division • ASTM- American Society for Testing and Materials • AATCC-American association of textile chemists and colorists • ANSI-American national standards Institution • ISO- International organization for standardization • BSI- British Standards Institute • BIS- Bureau of Indian Standards. • AQC of AAMA – Apparel Quality committee of American Apparel Manufacturer's Association.

Grade • The process of assigning a numerical value based on the number, size,and severity of defects observed during a visual inspection; the symbol, number, or letter used for any step in a multistep standard reference scale for a quality characteristic.

Session 5,6 What is Quality Specification Concept of Tolerances Ref: Quality Assurance for Textiles and ApparelSara J. Kadolph-Chapter 3 and 10

Specifications • Is a precise statement of a set of requirements to be satisfied by a material, product, system or service that indicates the procedures for determining whether each of the requirements is satisfied. • Requirements- are non negotiable.they need to be met for the specs to be satisfied.

Specifications • Specs describe requirements- in terms and/or numerical values. • Minimum – is the least or lowest acceptable value for any given parameter or dimension • Tolerance - describes the range of acceptable values. • Not all specs will include tolerances

Types of specifications • Open- allows for consideration of multiple vendors and includes a description of the character and /or performance desired in the product or material to be purchased. • Closed – specifies the exact material, component, or product by manufacturer or vendor and includes style numbers, trade names or other such specific identities.

Application of specifications. 1. Used to describe the materials ,procedures, dimensions and performance for a particular product or style. 2. Reflect the standard- co. standards, costs, customer needs and expectations and implementation abilities. 3. Used as a communication tool- for production, for suppliers and for customer. 4. To negotiate bids and contracts 5. Used for purchasing materials for production 6. Used as a determinant for quality.

SPECIFICATION GUIDELINES FOR PIECE GOODS INSPECTION *Fabric Yardage / Width *Hand feel / Quality *Color / Print *Fabric Weight *Wash & Dry Shrinkage *Color Fastness * What percent of goods inspected prior to cutting? * Are shade controlled and segregated by lots at storage stage? * Use of a light box? * Spectrophotometer? * What is the light source used? * Is there pre-testing on the shrinkage prior cutting? * How is the pre-testing done? * Records on shade bands?

Garment spec sheets • Specification sheets provide important details to ensure the correct execution of patterns into finished garments. • Spec sheets help to produce accurate samples, which improves turnaround time and simplifies communication during all stages of manufacturing and quality control. • Spec sheets include detailed technical diagrams, construction notes, finished garment measurements, fabric yields and material and trim details.

Session7,8 Assignment 1- assigned on 20.08.10; To be submitted on 27.8.10; time- 3 hrs(2 sessions) ; marks -20

Assignment 1- 20 marks • Prepare a garment specification sheet for a garment of choice, inspect the garment and record the inspection report in the prescribed format. • Individual assignment • Criteria of evaluation • Selection of garment- 3 marks • Specification sheet-7 marks • Inspection report – 10 marks

O

Session 9,10 Fabric Inspection ;Defects Testing Ref:Managing Quality in the apparel IndustryMehta and Bharadwaj-Chapter 2,Pages 14-20 and pg 75-77 and Chapter 3

Fabric- defects • Woven-

Knitted-

• • • • • • • • • • •

Barre Birdseye Coarse yarn Dropped stitches Fine yarn Missing Yarn Needle Line Run Tucking Defect ………….

Broken end Broken Pick Coarse end/Pick Color Fly Yarn Double end/double pick End out Mispick Hole Shade Bar Slub Thick and Thin Places

• ……..

Fabric • Inspection And Grading – 4 point system – 10 point system – Graniteville 78 system

Fabric grading 4 point system

10 point system

Allows max. 4 penalty points to one linear yard

Allows max.10 points per linear yard

Points for only length wise defects and holes

Warp as well as filling defects carry points

Sensitive to width of Not sensitive to width fabric of fabric Total defect points per If no. of penalty points 100square yards should are >> Risk Decision

Quality

Accept the lots

Reject the lots

Acceptable

O.K.

Producer’s Risk

Rejectable

Consumer’s Risk

O.K.

Acceptance Sampling System Definitions & Terminology

Sampling Plan: A sampling plan indicates the number of units of products from each lot or batch which are to be inspected (sample size or series of sample sizes) and the criteria for determining the acceptability of the lot or batch (acceptance and rejection numbers)

Inspection by Attributes: Inspection by attributes is inspection whereby either the unit of the product is classified simply as conforming or nonconforming (Good or Bad), or the number of nonconformities in the unit of products is counted, with respect to a given requirement or set of requirements.

Acceptance Sampling • Attribute sampling is usually based on Poisson statistics, where sample size and acceptance number (maximum number of BAD units in the sample) are specified. • This generates an Operating Characteristic (OC) that is a plot of the probability of lot acceptance (or confidence level) vs. percent defective in the total lot from which the sample was randomly selected – which take the form of Acceptance sampling charts or tables.

Acceptance Sampling System Definitions & Terminology

Acceptable Quality Limit (AQL): The AQL is the quality level that is the worst tolerable process average when a continuing series of lots is submitted for acceptance sampling. (ANSI/ASQ Z1.42003) Also defined as- the maximum percentage defective that for the purpose of sampling inspection can be considered satisfactory as a process average.

Acceptance Sampling System Definitions & Terminology Inspection Level. The inspection level determines the relationship between the lot size and the sample size.

3 general inspection level – I , II, III • Level II is designated as normal and will be used unless another inspection level is specified. • Level I requires about half the amount of inspection of inspection as level II, and is used when reduced sampling cost are required and a lower level of discrimination can be tolerated. • Level III requires about twice the amount of inspection as level II, and is used when more discrimination is needed. 4 special inspection levels – S1, S2, S3, S4 • Use special inspection level when sample size must be kept small and larger sampling risks can be tolerated.

Acceptance Sampling System Three Types of Sampling Plans – – –

Single Sampling Plan. Double Sampling Plan. Multiple Sampling Plan.

Provisions for each type of sampling plan 1. Normal Inspection 2. Tightened Inspection 3. Reduced Inspection

Sampling Procedures for Inspection by Attributes (MIL-STD 105E, ANSI/ASQ Z1.4) 1. Determine the lot size 2. Choose the inspection level to obtain the desired sample size code letter 3. Determine the appropriate type of sampling plan to use (single, double or multiple) and the provision of the plan (single, tightened or reduced) 4. Enter the appropriate table with the desired AQL and sample size code letter to find the type of sampling plan to be used (sample size, acceptance and rejection number)

Sampling Procedures for Inspection by Attributes (MIL-STD 105E, ANSI/ASQ Z1.4) Sample Size Code Letters

Lot or Batch Size

Special Inspection Level

General Inspection Level

S-1

S-2

S-3

S-4

I

II

III

8 15 25

A

A

A

A

A

A

B

A

A

A

A

A

B

C

A

A

B

B

B

C

D

50 90 150

A

B

B

C

C

D

E

B

B

C

C

C

E

F

B

B

C

D

D

F

G

280 500 1,200

B

C

D

E

E

G

H

B

C

D

E

F

H

J

C

C

E

F

G

J

K

3,200 10,000 35,000

C

D

E

G

H

K

L

C

D

F

G

J

L

M

C

D

F

H

K

M

N

D

E

G

J

L

N

P

to

150,000 500,000

D

E

G

J

M

P

Q

and

over

D

E

H

K

N

Q

R

2 9 16

to

26 51 91

to

151 281 501

to

1,201 3,201 10,001

to

35,001 150,001 500,001

to

to to

to to

to to

to to

Sampling Procedures for Inspection by Single Sampling Plan For Normal Inspection ( Master Table Attributes (MIL-STD 105E, ANSI/ASQ Z1.4) Sample size

Sample

code

size

letter

Acceptable Quality Limit (Normal Inspection) 0.010 0.015 0.025 0.040 0.065 0.10

0.15 0.25

0.40

0.65

1.0

1.5

2.5

4.0

6.5

10

15

25

4

Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac

A

2

B

3

C

5

D

8

E

13

F

20

G

32

H

50

J

80

K

125

L

200

M

315

N

500

P

800

0 1

1 2

2

1 2

2 3

3

1 2

2 3

3 4

5

1 2

2 3

3 4

5 6

7

1 2

2 3

3 4

5 6

7 8 10

1 2

2 3

3 4

5 6

7 8 10 11 14

1 2

2 3

3 4

5 6

7 8 10 11 14 15 21

1 2 2 3

3 4

5 6

7 8 10 11 14 15 21 22

1 2 2 3 3 4

5 6

7 8 10 11 14 15 21 22

0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1

7 8 10 11 14 15 21 22

1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

0 1

1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

0 1 0 1

1 2 2 3 3 4 5 6

1 2

1 2

2 3 3 4 5 6 7 8 10 11 14 15 21 22

2 3

3 4 5 6 7 8 10 11 14 15 21 22

Single Sampling Plan Select sample

Inspect sample

Make decision

The decision to accept or reject the lot is made based on the results of a single sample

Double Sampling Plan Select sample

Inspect sample

If there is not a clear accept/ reject decision from inspection of the first sample, a second sample is taken and the decision is made based on the results of the combined samples.

Is sample clear accept or reject

Resample

Make decision

Inspect Resample

Sampling Procedures for Inspection by Attributes (MIL-STD 105E, ANSI/ASQ Z1.4)

Example:A lot containing 12, 000 units is to be inspected using General Inspection Level II to a 2.5% AQL. Single sampling plan is to be used.

Sampling Procedures for Inspection by Attributes (MIL-STD 105E, ANSI/ASQ Z1.4) Sample Size Code Letters Lot or Batch Size

Special Inspection Level

General Inspection Level

S-1

S-2

S-3

S-4

I

II

III

8 15 25

A

A

A

A

A

A

B

A

A

A

A

A

B

C

A

A

B

B

B

C

D

50 90 150

A

B

B

C

C

D

E

B

B

C

C

C

E

F

B

B

C

D

D

F

G

280 500 1,200

B

C

D

E

E

G

H

B

C

D

E

F

H

J

C

C

E

F

G

J

K

3,200 10,000 35,000

C

D

E

G

H

K

L

C

D

F

G

J

L

M

C

D

F

H

K

M

N

D

E

G

J

L

N

P

to

150,000 500,000

D

E

G

J

M

P

Q

and

over

D

E

H

K

N

Q

R

2 9 16

to

26 51 91

to

151 281 501

to

1,201 3,201 10,001

to

35,001 150,001 500,001

to

to to

to to

to to

to to

Sampling Procedures for Inspection by Single Sampling Plan For Normal Inspection ( Master Table Attributes (MIL-STD 105E, ANSI/ASQ Z1.4) Sample size

Sample

code

size

letter

Acceptable Quality Limit (Normal Inspection) 0.010 0.015 0.025 0.040 0.065

0.10

0.15

0.25

0.40

0.65

1.0

1.5

2.5

4.0

6.5

10

15

25

4

Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac

A

2

B

3

C

5

D

8

E

13

F

20

G

32

H

50

J

80

K

125

L

200

M

315

N

500

P

800

0 1

1 2

2

1 2

2 3

3

1 2

2 3

3 4

5

1 2

2 3

3 4

5 6

7

1 2

2 3

3 4

5 6

7 8 10

1 2

2 3

3 4

5 6

7 8 10 11 14

1 2

2 3

3 4

5 6

7 8 10 11 14 15 21

1 2

2 3

3 4

5 6

7 8 10 11 14 15 21 22

1 2

2 3

3 4

5 6

7 8 10 11 14 15 21 22

1 2

2 3

3 4

5 6

7 8 10 11 14 15 21 22

1 2

2 3

3 4

5 6

7 8 10 11 14 15 21 22

1 2 2 3

3 4

5 6

7 8 10 11 14 15 21 22

1 2

2 3 3 4

5 6

7 8 10 11 14 15 21 22

2 3

3 4 5 6

7 8 10 11 14 15 21 22

0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1

1 2

Acceptance Sampling System Definitions & Terminology

Normal Inspection - Used at the start of the inspection activity. Tightened Inspection - Used when the vendor’s recent quality history has deteriorated (acceptance criteria are more stringent than under normal inspection) Reduced Inspection - Used when the vendor’s recent quality history ahs been exceptionally good (sample sizes are usually smaller than under normal inspection).

Acceptance Sampling System Switching Procedures

Assignment 2 • Students to select a set of 2 different defective garments. Each student needs to go through the garments and list down the defects. All garments need to be analyzed for all possible cutting room, sewing room, finishing room and fabric defects and their possible remedies. • Class assignment – to be completed on 1.12.10 and presented to class on 3.12.10 at 10.30 a.m • Students will be marked individually for the selection of the garment and the analysis of the defects with their possible prevention method.

Buyers Audit criteria BUYER Manual

Generally included areas

Vendor contractual terms

Fabric inspection, inline and final inspection procedures and formats to be used

Measurement criteriahow to measure

Defect criteria and tolerances

Packing ,labeling, shipping requirements

Meaning of AQL When a consumer designates some specific value of AQL for a certain nonconformity or group of nonconformities, it indicates to the supplier that the consumer’s acceptance sampling plan will accept the great majority of the lots or batches that the supplier submits, provided the process average level of percent nonconforming (or nonconformities per hundred units) that the consumer indicates will be accepted most of the time by the acceptance sampling procedures to be used. The sampling plans provided herein are so arranged that the probability of acceptance at the designated AQL value depends upon sample size, being generally higher for larger samples than for smaller one, for a given AQL. The AQL alone does not describe the protection to the consumer for individual lots and batches, but more directly relates to what might be expected from a series of lots or batches, provided the steps indicated in this sampling procedures are taken.

Acceptance Sampling System Definitions & Terminology

Percent nonconforming – The percent nonconforming of any given quantity of units of product is one hundred times the number of nonconforming units divided by the total number of units of products, i.e.: Percent nonconforming =

number of nonconforming number of units inspected

X 100

Acceptance Sampling System Switching Procedures Normal to Tightened. When normal inspection is in effect, tightened inspection shall be instituted when 2 out of 5 consecutive lots or batches have been non-acceptable on original inspection (i.e. ignoring resubmitted lots and batches for this procedure). Tightened to Normal. When tightened inspection is in effect, normal inspection shall be instituted when 5 consecutive lots or batches have been considered acceptable on original inspection.

Acceptance Sampling System Switching Procedures Normal to Reduced. When normal inspection is in effect, reduced inspection shall be instituted providing that the following conditions are satisfied:

a. The preceding 10 lots or batches have been on normal inspection and all have been accepted on original inspection; and b. the total number of nonconforming units in the samples from the preceding 10 lots or batches is equal to or less than the applicable number given in the limit number sampling table. If double or multiple sampling is in use, all samples inspected should be included, not “first” samples only ; and c. Production is at steady rate; and d. Reduced inspection is considered desirable.

Acceptance Sampling System Switching Procedures Reduced to Normal. When reduced inspection is in effect, normal inspection shall be instituted if any of the following occur on original inspection:

a. A lot size or batch is rejected; or b. A lot is consider acceptable under the special procedures for reduced inspection where the sampling procedure may be terminated without making a decision; or c. Production becomes irregular or delayed; or d. Other conditions warrant that normal inspection shall be instituted.

Acceptance Sampling System Switching Procedures Discontinuation of Inspection. In the event that 5 consecutive lots remain on the tightened inspection, inspection under the provisions of this standard should be discontinued pending action to improve the quality of submitted material.