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 requirements-Philip 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

Positioning of a company based on Garvin`s Model

1. Performance

2. Features

3. Reliability

4. Conformance

5. Durability

6. Serviceability

7. Aesthetics

8. Perceived quality

Dimensions of quality1.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 quality3.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 customers 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 Industry-

Mehta and Bharadwaj-Chapter 14

Quality Assurance for Textiles and Apparel-

Sara 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-uses1. 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 childrens clothing. Only childrens upper

outerwear. Sizes 2t to 12.

Wisconsin Law(ATCP 139)-a State regulation:

No drawstrings in the hood and neck area of all

childrens clothing. All childrens 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 Apparel-

Sara 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.

*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?

SPECIFICATION GUIDELINES FOR PIECE GOODS INSPECTION

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


Mehta and Bharadwaj-Chapter 2,Pages 14-20 and pg 75-77

and Chapter 3

Fabric- defects

Woven- Knitted- Broken end Barre

Broken Pick Birdseye

Coarse end/Pick Coarse yarn

Color Fly Yarn Dropped stitches

Double end/double pick Fine yarn

End out Missing Yarn

Mispick Needle Line

Hole Run

Shade Bar Tucking Defect

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 Graniteville 78

Allows max. 4 penalty

points to one linear yard

Allows max.10 points

per linear yard

Max.no.of points

per linear yard=

fabric width /9

width in inches.

Points for only length

wise defects and holes

Warp as well as filling

defects carry pointsLength of defect is

counted-can be weft

or warp

Not sensitive to width

of fabric

Sensitive to width of

fabric

Sensitive to width

of fabric

Total defect points per

100square yards should

not exceed 40

If no. of penalty points

are

4 point system

Size of defects (Inches) Assigned Points

3 inches or less 1

Over 3 but not over 6 2

Over 6 but not over 9 3

Over 9 inches 4

All textiles are evaluated on a square yard computation. The formula used to determine the point count level of a roll of fabric is as follows:

Total Points x 3,600 = Points per 100 yard2

Inspected Yards x Cuttable Fabric Width (in)-----------------------------------------------------------------------------------------------------------------------------------------------------

10 point system

Size of Defect (Inches) Warp Assigned Points

1 inch or less 1

1 to 5 inches 3

5 to 10 inches 5

10 to 36 inches 10

Size of Defect (Inches) Weft Assigned Points

1 inch or less 1

1 to 5 inches 3

5 inches to half width 5

Large than half width 10

Fabric Check ListDivision/Season: Style:

Fabric Pattern#: Type

Fabric Supplier: Roll #:

Piece Length:

1)General Appearance (against weaving/dyeing/ printing standard): ________

2)Construction:Check against hand standard): ________

3)Width( as specified in contract): ________

4)Piece length (as per tag and packing list): ________

5)Design/Pattern and colors/shades (as per approved strike off or lab dip): ________

-Any repeat variation ________

6)MAJOR DEFECTS1-Centre to Selvedge variation _________

2- End to End shading _________

3-Broken or missing ends/Picks _________

4-Torn ,Wavy, Folded or Tight Selvedges _________

5- Coarse Yarn in Warp or Weft _________

6- Holes _________

7-Double or multiple ends/picks _________

8-Loom stop marks _________

10-Noticeable Shade or filling bars _________

11-Noticeable Dead Crease mark/line _________

12-Noticeable Dye Streaks and stains through the roll _________

13- Bowing or skewing _________

14- Reed marks _________

15-Foreigh matter/soiled yarn _________

16-Neps _________

17-Oil Stains _________

18----------- ________

Gap standards for Piece goods Inspection

Testing

The analysis and evaluation of a material or

product to assess its characteristics, quality

or performance.

Test method- is a definitive procedure for

the identification, measurement, and

evaluation of one or more qualities,

characteristics or properties of a material,

product, system or service that produces a

test result.

Testing of fabrics Precision: the degree of agreement within a

set of observations or test results obtained by using a test method.

Accuracy: the degree of agreement between the true value of the property being tested ( an accepted standard value) and the average of many observations made according to the test method, preferably by many observers.

Reliability

Testing conditions

Standard Humidity and temperature

conditions to be maintained-

Relative humidity-65+2%

Temperature 21+1oC(70+ 2oF)

Min. 4 hrs in standard test conditions to

reach equilibrium

Testing of fabrics Fabric Strength Yarn Count, Yarn Twist, Fabric

construction, Fabric weight and width.

Yarn Slippage

Color fastness- to light, washing, rubbing, sunlight,

perspiration, chlorine ,dry cleaning, heat etc.

Dimensional Changes In Fabrics Due To Laundering, Dry-

cleaning, Steaming, Pressing

Bow and Skewness

Fabric Thickness

Pilling

Abrasion Resistance

Testing of fabrics

Each individual to conduct testing of fabrics in the F&T testing lab and record the following in the log book:

1The test being conducted

2.The standard used

3.The test requirements

4.Method of testing and

5.The instrument used

6. Any special instructions/ conditions for the test.

Session 11-14

Testing at lab

Session 15

Trims DefectsRef: Mehta and Bharadwaj-Chapter 3

Trims Defects

Sewing threads-

Imperfections in the yarn

Finish

Color

Package density

Winding

Yardage

Trims defects -ZippersTo check for-

Dimensions

Locks at ends and tab-

to be securely attached

Color of tape

Tape quality- no

wrinkling/puckering

Fading of color on

washing or ironing

Deformities due to

washing/ironing

Kinds of defects-

Ratcheting

Shear

Slider distortion

Sewing

Bottom stop

Hump

Popping

Wrongly placed closures at zip

end

Chemical degradation

Design problems

Trim Defects

Buttons

Clear holes

Uniform thickness

Color

Laundering/ironing/dry

cleaning pressures

No cracked edges or

sharp edges at holes

Uniform distance of

holes

Buckles

Sharp edges

Color/material-

appropriate for use

Snap Fasteners

Close properly

Metal quality

No sharp edges after

attaching

Testing of TrimsZippers Durability of finish of zippers to laundering

Colorfastness of zippers to laundering

Colorfastness of zippers to light

Colorfastness of zippers to crocking

Colorfastness of zippers to laundering

Durability of finish of zippers to dry cleaning

Resistance of zippers to salt spray (fog)

Measuring of zipper dimensions

Strength tests of zippers

Operability of zippers

Testing of Trims

Buttons

Impact Resistance

Shape

Uniformity

Resistance to Unsnapping - Snap Fasteners

Hook and loop fasteners

peel strength

sheer strength

shrinkage,

color fastness

Testing of Trims

Elastic-

Resistance to degradation (becoming loose,

losing elasticity) due to laundering

Elastic Limit Testing

Fusible Interlining

Bond Strength

Shrinkage and Stretch

Delamination and Strike back

Testing of Trims

Sewing threads Friction testing

Colorfastness test & abrasion resistance

Yarn number testing

Twist balance

Shrinkage

Strength and Elongation

Twist

Evenness

Diameter (Thickness)

Mid term

Post mid term session 17,18

Procedures practiced for Quality

Control and Assurance

(Cutting,Fusing)


Mehta and Bharadwaj-Page 34-42

Cutting room Quality procedures

Cutting Deptt.-activities

Fabric inspection

Pattern making

Marker planning

Spreading

Cutting

Bundling

Ticketing

Fusing

Pattern

Basic block + seam allowances = working patterns

working patterns are graded= full set patterns

Full set patterns adjusted for fabric characteristics e.g shrinkage factors= production patterns

Each graded paper pattern must have the following information written on it-size,cut,grain line and name of component part.

Requirements of Marker Planning

1) Nature of the fabric and desired result in

the finished garment-

pattern alignment to grain

design characteristics of finished style

pattern style

2) Requirements of quality in cutting

knife clearance

pattern count

appropriate labeling

3)Requirements of Production Planning

Factors affecting Marker Planning

Fabric Characteristics

Differences in face & back.

Lengthwise /crosswise symmetry

Need for matching the design

Length of design repeat

Fabric width

Characteristics of Pattern pieces

As number of garment sizes on marker increases the fabric utilization becomes better.

Marker making Check ListDivision/Season: Style:

Fabric Pattern# and Swatch: Roll #:

Piece Length:

Width of Piece Goods:

Fabric properties- Directional/Non-Directional

.

Cutting -Spreading

Factors affecting spreading

form or nature of the material package

Direction of the material surface w.r.t the

cutting table surface

Direction of surface nap or design w.r.t

the ends of the spread.

Cutting -Spreading Process of Spreading- requirements

Splice points to be marked- to avoid fabric flaws

Shades to be sorted out

Ply direction

Stability of the lay

Alignment of plies- length and width

Ply tension

Static elimination

Distortion of spread

Fusion of plies

Cutting-requirements

Precision of cut

Clean edges-

no fraying or jagged edges

Unscorched , Unfused surface-appropriate cutting

equipment;

shape of the part and

condition of the knife

Support of the lay

Consistent cutting

Depth of spread

no. of plies and the thickness of ply

Density of material-fabric weight-fibre;yarn size and count

Cutting-requirements

Quality criteria-

Knife Clearance

Accuracy of cut-

marker precision

stability of the lay

proper cutting sequence

Cutting pitch

Choice of appropriate cutting knife

Condition of knife blade

1. Temperature-Need an optimum ``glue-line

temperature or ``interface temperature``. Once this

temperature is reached the bonding will occur.

At the correct temperature, the resin changes from a

dry solid to a viscous liquid which penetrates the

fibers by suitable application of pressure. After

cooling this re-solidifies and bonding occurs thus.

If the temperature is not reached- fusing will not

take place as resin will not polymerize.

If the temperature is exceeded-can have problems of

`strike-back'; adhesive migration and low bond

strength can be experienced.

Fusing- process parameters

2.Time-The function of the time element is to compensate for the delay in the transmission of heat from the source to the fusible agent. It is simply the time duration the composite should be exposed to heat. This time component relates to-

The time when the 2 plates of the press actually meet with the correct specific pressure or the time for which the assemblies are actually in the heating zone if a continuous press is used.

The type of interlining used i.e whether it has a low or high melt adhesive system or if it has a light or heavy weight substrate.

The type of application for which the fusible is to be used

The nature of the shell fabric being used.

The type of fusing equipment employed.

Fusing - process parameters

Fusing - process parameters3.Pressure - pressure is necessary to ensure

that intimate contact is effected between fusible interlining and the shell fabric.

Adequate heat transfer takes place

Controlled even penetration of the of the adhesive takes place into the fibers.

Pressure is normally recommended depending on the viscous or flow property of the glue.

4.Cooling cooling is very necessary for the bonding to take place after the fusing process is over

Fusing - process parameters Sequence of the process parameters-

first heat should be applied to raise the temperature of the interlining-fabric composite to the glue-line temperature.

Pressure is then applied to enable the adhesive dots of interlining to penetrate the base fabric.

Heat and pressure should not be applied together as this may result in flattening of adhesive dots and resulting unnecessary stiffness in the fused fabric due to increasing area of contact between fabric and interlining.

Flattening of adhesive dots also result in less penetration of adhesive onto the base fabric thus reducing the peel-bond strength.

Cooling after the final pressure.

Fusing Performance parameters also depend on-

material and weight of the substrate and

fiber content- cotton and rayon give softer hand

feel;polyester and nylon are used for their strength,

stability and resiliency.Blends of fibers are very

common.wool and hair fibers may be used to provide

resiliency and shape retention and used in wool piece

goods.

resin application methods - commonly used- others include-

scatter coating preformed systems

dry dot printed coating extrusion laminating

paste coating & emulsion coating

Fusing -Quality parameters

Quality problems associated with fusing

Strike back

Strike through

Shrinkage

Delamination

Color change

Bubbling

Boardiness

Session 19,20

Understanding quality procedures in

sampling

Different stages of samples

Product development process

Proto Sample

Fit sample

Size set sample

Sealor/sealed sample

Pre production sample/

pilot run sample

TOP sample

Shipment sample

Sampling process

Photo Samples/Salesman Samples

Sampling Process Once the merchandiser/designer approve the proto sample

then specs are corrected and fit sample is made.

Corrections on the fit sample lead to a graded size specs and size set

Photo samples/salesman samples in correct design/color and sample size are submitted next

Pre production sample (PPS)/pilot run sample is sent with the bulk fabric and all trims in correct placement with the required after treatment and packaging to make the buyer aware of the shipment which is expected from bulk.

A counter sample or sealed sample is sent along with all corrections made , in correct construction and correct trims with any special instructions from the buyer to the production for production reference.

Sewing room Quality procedures

Quality Assurance for Textiles and Apparel-Sara J. Kadolph-Page

375,

Managing Quality in the apparel Industry-Mehta and Bhardwaj

Ch 2

Type of Sample Size Material Stages at which it is sent PurposePrototype Samples Average Nearest substitute of fabric At which suppliers are still trying to confirm the

style and trying to get an order

To finalize Fit, construction, and converting sketch/design into

garment.

Salesman samples Average Exactly same fabric After approval of prototype, still trying to get

order from buyer

To know the opinion of the store owners whether the style would sell

in the market or not, and the demand of that product.Helps to book

colorwise-size wise quantities

Fit sample Average Could be substitute if not available. Made after order is booked. Refining a fit & construction from either prototype or salesman

sample, and/or make changes to these samples as required in the

design.

Size-set samples All sizes Exactly same fabric, trims and other value

added work

After fit and construction of average size is

approved.

The purpose is to check the actual approval for production of all the

sizes and also to approve the desired value added work (like printing,

embroidary etc.) to be done on the garment.

Sealer's sample Average Exactly same fabric, trims and other value

added work

After Size-set for the style has been approved. This sample sealed for the bulk i.e. manufacturer will have to make the

exact pieces for bulk.

Pre-production

sample/Advertisement/Photosh

oot sample

Average Exactly same When the initial yardage of bulk fabric is

received.

This is made for advertisement, making catalogue, photoshoot or only

for buyer's referance that how the garment will look like finally.

Top of production Average Exactly same During the execution of production order. To see whether the bulk pieces are coming out alright or not, whether

the quality and construction is matching to the sealer sample or not.

Vendor always tries to select the best quality pieces to send as TOPs.

Shipment samples Average Exactly same Before sending the shipment to the buyer's

warehouse.

Shipment sample is a representative of bulk reaching buyer's

warehouse/DC. It goes from vendor to buyer's office, to buyer's

warehouse/distribution centre and finally to Store. Shipment sample

need to be in correct colour, trims, packing etc.aganist which DC will

check the bulk quantity received.

Q.A in sewing department

Two aspects-

1. Operator training as related to quality -operators

to be

1. Aware of the quality standards of the organization

2. Aware of the quality parameters with regards to the

product's fit ,appearance and construction

3. Aware of what constitutes a defect and how to avoid

it.

4. Aware of the correct usage of the fabric and trims

being used.

Q.A in sewing department

2. Setting quality standards for sewing

operations

Written quality specs for each operation

spi

Seam type, stitch type, machine type

Matching and/or balancing requirements

Sketch and /or Sample of quality standard

for each operation

Tolerances if any

Sewing defects

Needle hole damage

Feed damage

Skipped stitches

Thread break

Broken/joint stitches

Seam grin

Seam pucker

Pleated seam

Wrong spi

Uneven stitch density

Oil spots/stains

Poorly formed stitches

Sewing defects

1. Needle damage

Causes holes, picked threads, ruptured threads

or other damages to the fabric.

Caused by wrong size or type of needle, blunt

needle, needle point damaged, needle heat or

machine needle feeding.

Can be remedied by changing the needle or

adjusting the feed mechanism.

Sewing defects

2. Feed Damage-

Causes damage on the fabric surface or on seam

Caused by incorrect type of teeth, excessive pressure by foot,improper alignment of feed dog and presser foot, damaged throat plate or excessive machine speed

Remedied by adjusting the feed dog teeth,pressure of the foot,or changing the damaged throat plate

Sewing defects

3. Skipped stitches-

Causes excessively long stitches of two or

more stitch lengths during the stitch cycle

Caused by the hook irregularly failing to pick

up the loop of thread from the needle`s eye .

Can be remedied by adjusting the type of

needle, length of needle, bobbin hook

position,matching thread to needle

Sewing defects

4. Thread breaks-

Caused by too thick a thread for the needle,too thin a thread for the needle, needle heat,operator working unrhythmically or tight tensions

Remedied by adjusting the correct thread size to needle size, adjusting the machine tension, operator training and using a treated thread to counter needle heat.

Sewing defects

5. Broken stitches

Cause unseemly seam appearance and less strength of the seam

Caused by wrong stitch type,too tight tensions,a badly formed joint in the seam where the second line of stitches run over the first and crack it, sharp feeds and too great a pressure

Can be remedied by adjusting the feed dog position and pressure,adjusting the tension,selecting the correct stitch type for the seam.

Sewing defects

6. Seam grin-

Causes the seam stitch line to be seen and

seam to open up when pressure is applied

Caused by too loose a tension or too large a

stitch length or the wrong type of stitch.

Can be remedied by adjusting the stitch

density, stitch tension or the stitch type.

Sewing defects

7. Seam pucker-

Causes the seam to appear wrinkled

Caused by differential fabric stretch,differential fabric dimensional instability,due to extension in sewing thread, due to sewing thread shrinkage,due to structural jamming, due to mismatched patterns

Remedied by using special feed systems,using dimensionally stable fabric,adjusting tension settings or changing thread type,matching performance of thread to fabric,fabric design change or sewing at bias and proper cutting respectively.

Sewing defects

8. Staggered stitches-

Causes poor appearance of the seam

Caused by yarns in the fabric deflecting

needle away from the straight line of

stitching,faulty feed motion,incorrect needle

Remedied by stitching on a slightly bias angle

where the fabric is hard woven,adjusting the

feed mechanismor changing the needle.

Sewing defects

9. Improperly formed stitches-

Causes reduced stretch in the stitch line,causes needle thread to show on the underside or bobbin thread to be visible on top

Caused by poor tension,incorrectly adjusted stitch timing or improperly fitting machine components

Remedied by adjusting the feed mechanism, stitch timing,tension

Sewing defects

10. Variable stitch density

Caused by insufficient foot pressure, slippery

or sticky surface of fabric

Remedied by increasing the pressure or using

specialized feed systems.

Seaming defects

Incorrect width of inlay

Incorrect shape of sewing line

Insecure back stitch

Twisted seam

Mismatched checks/stripes

Reversed garment parts

Wrong seam type

Wrong shade of thread

Extraneous part caught in seam

Assembly defects

Finished components not correct to

size/shape/symmetry

Components/parts wrongly positioned

Garment parts pleated/twisted/showing

bubbles/fullness

Parts shaded

Wrong one way direction

Mismatched trimming

Pressing and finishing defects

burnt or scorched garments

water spots or stains

gloss or change in color

flattened nap or surface

broken/damaged trims

incorrectly formed crease

garments not thoroughly dried

lining defects- creases, shine marks, pleats

shrinkage/elongation due to heat moisture or incorrect

pressing

Inspection

Quality Assurance for Textiles and Apparel-Sara J. Kadolph

Chapters 11-13,

Managing Quality in the apparel Industry-Mehta and Bharadwaj

;Chapter 2 Page 42-74,

Act-

if positive results-

action is taken to replicate

the process improvements

across the board

standardization necessary here

if negative results-

plan stage is revisited

and cycle is repeated

Deming`s PDCA cycle

Plan

Check

Act Do

Check-

results of DO stage analyzed

desired objectives met or not

Planning-

what the customer

needs and wants

determine process

goals thru this

examine current process

in view of these goals

Do

implementation of this plan

implemented as a test

case in controlled setting

Inspection Loop

Inspection

Detection of defects

Feedback of the defects

to appropriate

personnelDetermination of

causes of defects

Correction of defects

Inspectors- Requirements1. Technical knowledge about the job

2. Good vision and color perception

3. Attention to detail

4. Thoroughness in procedure

5. Self-directed

6. Ability to take decisions without bias

7. Ability to work in a team

8. Reasonable knowledge of mats

9. Interest in maintaining the company's reputation for quality merchandise

10. Ability to communicate clearly- verbally and in written form

Inspection or audit

The visual examination or review of materials, product components and finished products on the basis of their adherence to some established set of standards ,specifications or requirements.

Can have inspection at different stages of the process- in-process inspection

Or at the end of the process- end process or final inspection.

Types Of Inspections- based on

stage in the production process

Inspection

At Source At arrival In ProcessFinished

Goods Vendor

Raw

Material

Fabric

Trims

Acc to

Dept

Acc to

Process

Stability

Setup

Patrol

Spreading

& Cutting

Sewing

Finishing

TYPES OF INSPECTION Material inspection

Inspection at the raw material stage.

Source inspection Inspection at the suppliers place including materials, components,

products or documents

In-process inspection Visual inspection of all parts, components and materials during the

production process

In-coming goods inspection Inspection done for goods outsourced

Vendor inspection Inspection done to check vendors facility and operations.

Product inspection Inspection done to ensure whether the product meets the required

standards and specification

Inspection or audit1. Raw Material Inspection

Fabric Inspection

length,

width,

quality level (visual and testing) and

Uniformity requirements

Trims Inspection

Interlinings Inspection.

2. In-Process Inspection

Spreading

Cutting

Sewing

Fusing and Printing Operation

Pressing and Finishing Operation

Inline Inspection quality parameters

Spreading- Ply alignment, Ply tension, Fabric characteristics

and variations,

Splicing requirements and points,

width and length variation

Type of spread Marking

No. of pattern parts, grain line, pattern alignment, marker width, notches

Cutting- Frayed edges, pattern precision, notches, drills count

Embroidery/Printing Placement, wrong color, wrong print, measurements, missing parts

TYPES OF INSPECTION IN

APPAREL INDUSTRY INLINE INSPECTION

Self inspection/no external inspection

100% inspection

Random inspection

FINAL INSPECTION

100% inspection

Spot checking

Arbitrary inspection

Statistical or acceptance sampling

In-Process inspection Procedure Complete operational flow chart

Determine Inspection Points

Determine whether 100% or random sampling required.

Amount to be inspected in random sampling depends on-

Kind of Product

Quality policy of the company

Buyer requirements

Other factors such as time, financial constraints, labor restrictions etc.

Operation breakdown and flow

chart

Men's Tunic Shirt

In-Process inspection- Random

Sampling Procedure e.g.

1.Should audit complete finished bundle

2. Inspect every 4th bundle of every operator/operation based on the quality parameters of buyer's AQL or company standards

3. If bundle is rejected, then return the bundle to the operator and inspect the next 3 bundles.

4. If 3 bundles are o.k then go back to inspecting every 4th bundle

INLINE INSPECTION FOR

CONTINUOUS PRODUCTION

Inspection done using statistical sampling plans called

Continuous Sampling Plans (CSP)

Combination of 100% inspection and statistical sampling

Example:

100% inspection till a specified number of pieces are found

acceptable

Inspection of only fraction of the pieces produced

If a defective piece is found, revert to first step and follow

same procedure

* Specified number depends upon Accepted Outgoing Quality Level (AOQL)

122

Continuous Sampling Plan

Inspect 100%

i

Consecutive

acceptable

units

Inspect fraction f

of the units

Defect

found in

sample

NO

YES NO

YESFLOW OF

THE CSP-1

PLAN

In-Line Inspection

In-line inspection should be conducted at least once a shipment.

The checking criteria may be as below:

To check the fabric quality in terms of color shade, hand feel and printed patterns against the standards.

To check the measurements of semi-products against the size specification. When checking this, fabric shrinkage, stretch ability and other factors that may affect the measurement during manufacturing process must be taken into consideration.

In-Line Inspection

To check all trimmings in terms of color, function and shape against the approved trim cards, which include labels, hangtags, embroidery, prints, zippers, buckles, etc.

To check the construction in terms of styling and workmanship against the sealed sample.

As the non-conforming products are found, the maker should be pushed taking an immediate corrective action in order to have an immediate improvement

Classification Of Defects Critical Defect -A defect is defined as a defect that is

1)resulting in hazardous or unsafe conditions for individual using it or (2) Prevent performance of the tactical function of a major end item.

The critical defects can be

1)Loose components, i.e. buttons, snaps, stones or other miscellaneous parts or any extraneous element is found within a product (insect, part of accessory).;

2) Any items, which have sharp point, sharp edge, or potentially dangerous components, which can cause injury .i.e. broken needles, staples, snaps, rivets, wire and pins;

3) Drawstrings at head or neck for baby or kids products; and

4) Threads or trim which are excessively long or loose which could present a choking hazard to a baby or child if they become entangled.

Classification Of Defects

Major Defect -A defect is defined as a

major defect that results in failure, or

reduces materially ,the usability of the unit

of product for its intended purpose.

The major defects can be holes, broken

seam, obvious stains permanent in nature,

etc.

Classification Of Defects

Minor Defect -A defect is defined as minor

defect that is not likely to reduce the

usability of the product, but nevertheless

may negatively influence the sales.

The minor defects can be untrimmed

thread-ends, slight dirt in a non- noticeable

zone which can be removed, etc.

Product/defect Zones

Garment Zones- Areas which according to their visibility levels to the customer are accorded a status and the acceptance or rejection of the defect is prioritized according to the area or zone in which it occurs.

Based on the kind of defects occurring in specific zones, decisions are taken to accept or reject the product.

Product zones ref sara k.

Zone 1or A- areas with high visibility that are likely to be viewed at close distance at time of purchase. Shirts fronts till waist, back till a/h, bottoms- front; flared skirt- till low hip

Zone 2 or B- areas which are not visibly dominant but are visible in normal use. front waist area, back from A/h to 10 cm above hem , bottoms- back.

Zone 3 or C- areas normally hidden in everyday use but could be visible on occasions. shirt side seams , hem area, bottoms- hem of a long skirt full trouser-between knee and hem area, inseam area.

Garment Defect Zones

How to measure

Blazer/Jacket/Vest/Coat

A.Across chest - Measure straight across front at narrowest point between armhole seams. (Garment must

be fastened)

B.Chest/bust- Measure straight across front body, 1" below armhole, from edge to edge

C.Bottom/sweep - Measure along the bottom edge of garment.

D.Total body length from high point of shoulder- Measure from shoulder seam at neck straight down to the

bottom edge of garment.

E.Shoulder seam- -Measure from neck seam along shoulder to armhole seam.

F.Armhole (curved)- -Measure from the joint point of shoulder seam at armhole to joint point of underarm

seam at armhole, following the shape of curve line

G.Armhole (straight)- -Measure straight from the joint point of shoulder seam at armhole to joint point of

underarm seam at armhole.

H.Upper arm(1 " below armhole)- - measure straight across sleeve seam, parallel to sleeve opening.

I.Sleeve length from shoulder- -Measure from joint of shoulder seam at sleeve to bottom edge of sleeve

J.Sleeve length from centre back- -Measure from centre back neck seam across to shoulder seam, down to

bottom edge of sleeve.

K.Sleeve (2" above cuff)- -Measure 2" above cuff or finished edge, straight across sleeve (from edge to

edge).

L.Sleeve opening- -Measure along the edge of sleeve

M.Across shoulder- -Measure straight across back from shoulder/sleeve seam to shoulder/sleeve seam.

N.Across back - Measure straight across back at narrowest point between armhole seams

O.Centre back length - Measure from centre back neck seam, straight across to the bottom edge of garment.

P.Neck opening - Measure along neck seam from centre front to centre back.

Q.Flap width - Measure along the top of flap (from edge to edge).

R.Flap depth - Measure from centre of top edge of flap to bottom edge

S.Welt pocket opening - Measure along the welt pocket opening (from edge to edge).

T.Chest pocket from neck point - Measure from high point of shoulder seam at neck to top of flap or welt.

Jeans/Pants/Shorts/Skirt

Woven Bottom - Jeans/Pants/Shorts/SkirtA. Waist relaxed

B. High hip

C. Low hip

D. Thigh

E. Knee

F. Leg opening

G. Inseam

H. Outseam

I. Front rise

J. Back rise

K. Back pocket width

L. Back pocket depth

M. Front pocket opening

N. Centre back length

(for skirts )

O. Sweep

(for skirts only)

A. Measure along the centre of waistband. (Garment must be fastened)

B. Measure across hip at specified distance (usually 4" at centre front and side seams) below waist seam.

C. Measure across hip at specified distance (usually 8" at centre front and side seams) below waist seam.

D. Fold garment with inseams matching. Measure across the garment from front crease to back crease at bottom of crotch seams.

E. Fold garment with inseams matching. Specify distance (inches or cm) below crotch seam along inseam. Measure straight across leg from front crease to back crease at indicated point.

F. Measure along the bottom of leg.

G. Fold garment with inseams matching. Measure from cross of crotch seam straight along to the bottom of leg.

H. Fold garment with inseams matching. Measure straight along seam line from bottom of waistband to bottom of leg opening.

I. Measure from waist seam to crotch seam. If there is no waist seam, measure from top of the pants to crotch seam.

J. Measure from waist seam to crotch seam. If there is no waist seam, measure from top of the pants to crotch seam.

K. Measure along the pocket opening (from edge to edge).

L. Measure from top edge down to bottom edge at centre of pocket

M. Measure along pocket edge from waist seam to side seam, following the shape of curve line.

N. Measure waistband seam to the bottom hem. If there is no waistband, measure from the top of skirt to the bottom hem.

O. Measure along the bottom edge of hem.

Blouse/Shirt

Woven Top - Woven Shirt/BlouseA.Across chest

B. Chest/bust

C. Bottom/sweep

D. Total body length from high point of shoulder

E. Shoulder seam

F.Armhole (straight)

G. Upper arm

H. Sleeve (2" above cuff)

I. Cuff opening

J. Sleeve opening

K. Sleeve length from shoulder

L. Sleeve length from centre back

M. Across shoulder

N. Across back

O. Centre back length

P. Neck opening

Q. Neck opening inside

R. Front neck depth

S. Collar point to point

T. Neck circumference

U. Chest pocket from neck point

V. Chest pocket from centre front

A. Measure straight across front at narrowest point between armhole seams. (Garment must be fastened)

B. Measure straight across front body, 1" below armhole, from edge to edge

C. Measure along the bottom edge of garment

D. Measure from shoulder seam at neck straight down to the bottom edge of garment

E. Measure from neck seam along shoulder to armhole seam.

F. Measure straight from joint of shoulder seam at armhole to joint point of underarm seam at armhole.

G. (1" below armhole), measure straight across sleeve seam, parallel to sleeve opening.

H. Measure 2" above cuff or finished edge, straight across sleeve (from edge to edge), all pleats open.

I. Measure at middle of cuff across sleeve from fold to fold with cuff closed

J. Measure along the edge of sleeve.

K. Measure from shoulder/sleeve seam along top to bottom edge of sleeve

L. Measure from centre back neck seam across to shoulder seam, down to bottom edge of sleeve (Include cuff).

M. Measure straight across back from shoulder/sleeve seam to shoulder/sleeve seam.

N. Measure straight across back at narrowest point between armhole seams

O. Measure from centre back neck seam, straight across to the bottom edge of garment.

P. Measure along neck seam from centre front to centre back.

Q. Measure from inside edge of collar straight across to opposite inside edge of collar.

R. Create an imaginary line across neck at high point shoulder. Measure at centre front from the imaginary line to front neck seam.

S. Measure along the outer edge of top collar from point to point.

T. Measure from centre of button to the end of buttonhole along middle of collar band.

U. Measure from high point of shoulder seam at neck to top of pocket.

V. Measure from centre front to edge of pocket.

Knit Top

Knit topA. Chest/bust

B. Bottom/sweep

C. Upper arm

D. Sleeve opening

E. Armhole (curved)

F. Total body length from high point of shoulder

G. Sleeve length from shoulder

H. Sleeve length from centre back

I. Across shoulder

J. Neck opening inside

K. Front neck depth

L. Chest pocket from neck point

M. Chest pocket from centre front

N. Minimum neck stretch

A. Measure straight across front body, I" below armhole, from edge to edge.

B. Measure along the bottom edge of garment

C. (1" below armhole), measure straight across sleeve seam, parallel to sleeve opening.

D. Measure along the edge of sleeve.

E. Measure from the joint point of shoulder seam at armhole to the Joint point of underarm seam at armhole, following the shape of curve line.

F. Measure from shoulder seam at neck straight down to the bottom edge of garment

G. Measure from joint of shoulder seam at sleeve to bottom edge of sleeve.

H. Measure from centre back neck seam across to shoulder seam, down to bottom edge of sleeve.

I. Measure straight across back from shoulder/sleeve seam to shoulder/sleeve seam.

J. Measure from inside edge of collar straight across to opposite inside edge of collar.

K. Create an imaginary line across neck at high point shoulder. Measure at centre front from the imaginary line to front neck seam.

L. Measure from high point of shoulder at neck to top of pocket.

M. Measure from centre front to edge of pocket.

N. Stretch neck, do not overextend. Measure straight across the neck opening at neck seam inside edge to edge.

Final Inspection

It is the last inspection done before the buyer inspection

All the buyer specifications are checked for-

1. Form Fit checking

2. Sewing- needle damages, sewing defects, assembly defects, quality of seam, placement of labels, cleanliness , correct trims

3. Measurements

4. Final handfeel and look

5. Packing and packaging

Final Inspection

Final inspection can be conducted under the

following conditions :

The quantity in carton boxes must be at least up

to 80% of the total shipped quantity.

The sewing or assembly process must be

finished for the balance quantity (20% of the

total shipped quantity).

Final Inspection

Types of final inspection

No inspection

100%inspection

spot checking

arbitrary sampling

statistical sampling

Final Inspection

Spot checking - inspection of random shipments. Some shipments are inspected while others are not at all inspected

Arbitrary sampling - a certain percentage of shipment is inspected and the accept or reject decision is based on the inspection.

A major drawback is that either too little or too much is inspected.

Final Inspection

Statistical sampling-is a system based on the theory that a given amount of samples drawn at random from the production lot will reflect the percent defective in the lot with certain tolerance limits for the percent defectives and within certain limits of probability.

Acceptance sampling plans are used in statistical sampling as a tool to determine the lot acceptance or rejection of the lot

Acceptance Sampling System

SAMPLING PLANS AND

PROCEDURES

FOR

INSPECTION BY ATTRIBUTES

ANSI/ASQ Z1.4-2003

(ISO 2859-1)

(MIL-STD 105E)

History Standard military sampling procedures for inspection by attributes were

developed during World War II. Army Ordnance tables and procedures were

generated in the early 1940's and these grew into the Army Service Forces

tables. At the end of the war, the Navy also worked on a set of tables.

In the meanwhile, the Statistical Research Group at Columbia University

performed research and outputted many outstanding results on attribute

sampling plans. These three streams combined in 1950 into a standard called

MIL-STD. 105A. It has since been modified from time to time and issued as

105B, 195C and 105D. MIL-STD. 105D was issued by the U.S. government in

1963.

In 1971, it was adopted by the American National Standards Institute as ANSI

Standard Z1.4 and in 1974 it was adopted (with minor changes) by the

International Organization for Standardization as ISO Std. 2859.

The latest revision is MIL-STD 105E and was issued in 1989, and was

cancelled in February 1995 to reduce cost through the elimination of

duplication. ANSI/ASQ Z1.4 is nearly identical to MIL-STD 105E.


Acceptance sampling is used to determine whether to accept or reject a lot of material that has already been produced.

A lot is defined as a quantity of product accumulated under uniform conditions. For example, from one production line or machine.


Importance

Acceptance sampling

Do not provide any direct form of quality

improvement.

Not to inspect quality into the products, but

rather as an audit tool to ensure that the output of a

process conforms to requirements.


Aim

To induce a supplier to maintain a process average at least as good as the specified Acceptable Quality Limit (AQL), whilst at the same time providing an upper limit for the risk to the consumer of accepting the occasional poor lot.


Why not use 100% Inspection?

6 situations where 100% inspection is often not practical:

When testing is destructive

When inspection costs are extremely high

When time or technology limitations are constraints

When lot sizes are very large and the probability of inspection error is very high

When supplier quality history is good enough to justify less than 100% inspection

When potential liability risks are high enough to warrant some form of continuous monitoring

Acceptance Sampling SystemAdvantage

Less expensive because of less inspection.

There is less handling of the products.

It is applicable to destructive testing.

Fewer personnel are involved in inspection activities.

It often greatly reduces the amount of inspection error.

The rejection of entire lots often provides a stronger motivation to the supplier for quality improvement.

Acceptance Sampling SystemDisadvantage

Risk of accepting bad lots and rejecting good

lots.

Less information is usually generated.

Acceptance sampling requires planning and

documentation of the acceptance sampling

procedure whereas 100% inspection does not.

Acceptance Sampling System >>>

Accept the lots Reject the lots

Acceptable O.K. Producers Risk

RejectableConsumers

RiskO.K.

Decision

Quality

Risk


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.



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 Z1.4-

2003)

Also defined as- the maximum percentage defective that for the

purpose of sampling inspection can be considered satisfactory as a

process average.



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 SystemThree 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)


Attributes (MIL-STD 105E, ANSI/ASQ Z1.4)Sample Size Code Letters

to

to

to

to

to

to

to

to

to

to

to

to

to

to

and

150,001

500,001

Lot or Batch Size

501

1,201

3,201

150,000

500,000

over

2

9

16

26

51

91

8

15

25

50

90

150

3,200

10,000

35,000

500

1,200

151

281

D

10,001

280

35,001

D

D

C

General Inspection LevelSpecial Inspection Level

C

C

B

B

C

D

E

E

E

A

A

A

A

B

B

D

E

C

C

D

H

A

A

A

B

B

B

C

F

G

G

C

E

F

C

D

D

A

B

B

S-3S-2S-1

A

J

J

K

G

G

H

E

E

F

C

C

D

S-4

A

A

B

L

M

N

H

J

K

E

F

G

C

C

D

I

A

A

B

N

P

Q

K

L

M

G

H

J

D

E

F

II

A

B

C

P

Q

R

L

M

N

D

H

J

K

E

F

G

III

B

C

Sample

size Sample

code size 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 40 65 100 150 250 400 650

letter 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 Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re

A 2 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

B 3 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22 30 31

C 5 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22 30 31 44 45

D 8 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22 30 31 44 45

E 13 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22 30 31 44 45

F 20 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

G 32 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

H 50 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

J 80 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

K 125 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

L 200 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

M 315 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

N 500 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

P 800 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

Q 1250 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

14 15 21 22

Single Sampling Plan For Normal Inspection ( Master Table)

Acceptable Quality Limit (Normal Inspection)

1 2R 2000 2 3 3 4 5 6 7 8 10 11



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

Make decision

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 Inspect Resample



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.


Attributes (MIL-STD 105E, ANSI/ASQ Z1.4)Sample Size Code Letters

to

to

to

to

to

to

to

to

to

to

to

to

to

to

and

E

III

B

C

D

H

J

K

F

G

L

M

N

P

Q

R

II

A

B

C

D

E

F

G

H

J

K

L

M

N

P

Q

I

A

A

B

C

C

D

E

F

G

H

J

K

L

M

N

S-4

A

A

B

C

C

D

E

E

F

G

G

H

J

J

K

S-3S-2S-1

A

A

B

B

C

E

F

C

D

D

F

G

G

H

A

A

A

B

B

B

C

D

E

C

C

D

E

E

A

A

A

A

B

B

General Inspection LevelSpecial Inspection Level

C

C

B

B

C

D

E

D

D

C

151

281

D

10,001

280

35,001

3,200

10,000

35,000

500

1,200

26

51

91

8

15

25

50

90

150

2

9

16

150,001

500,001

Lot or Batch Size

501

1,201

3,201

150,000

500,000

over

Sample

size Sample

code size 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 40 65 100 150 250 400 650

letter 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 Re Ac Re Ac Re Ac Re Ac Re Ac Re Ac Re

A 2 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

B 3 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22 30 31

C 5 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22 30 31 44 45

D 8 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22 30 31 44 45

E 13 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22 30 31 44 45

F 20 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

G 32 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

H 50 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

J 80 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

K 125 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

L 200 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

M 315 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

N 500 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

P 800 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

Q 1250 0 1 1 2 2 3 3 4 5 6 7 8 10 11 14 15 21 22

7 8 10 11 14 15 21 22

Single Sampling Plan For Normal Inspection ( Master Table)

Acceptable Quality Limit (Normal Inspection)

1 2R 2000 2 3 3 4 5 6



Acceptance Sampling SystemDefinitions & Terminology

Normal Inspection - Used at the start of the inspection activity.

Tightened Inspection - Used when the vendors recent quality

history has deteriorated (acceptance criteria are more stringent

than under normal inspection)

Reduced Inspection - Used when the vendors recent quality

history ahs been exceptionally good (sample sizes are usually

smaller than under normal inspection).

Acceptance Sampling SystemSwitching 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

Defect criteria and tolerances

Measurement criteria-how to measure

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 consumers 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.



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.:

number of nonconforming

number of units inspectedPercent nonconforming = X 100


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.


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.


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.


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.

assqc

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