SEVEN TOOLS OF QUALITY:

 

Collecting and analyzing data is the foundation on which the effective management of quality rests. The so called “seven tools of quality” will help you effectively collect and analyze data

The seven tools of quality are:

1. § Cause and effect diagram
2. § Check sheet
3. § Control chart
4. § Flow chart
5. § Histogram
6. § Pareto chart
7. § Scatter diagram

A summary of these tools are provided here.

1. CAUSE AND EFFECT DIAGRAM:

This diagram is also called as fishbone diagram because it looks like skeleton of a fish. The idea is first to identify and state the problem , which is in essence an effect if something that happened in a process and think through various causes that may have resulted in an undesired effect. Drawing a cause and effect

diagram helps one think systematically and logically. It graphically illustrates the relation between a given outcome and all the factors that influence this outcome.

2. CHECK SHEET:

A check sheet is nothing but a form used to collect data in such a way that it makes not only the collection of data easy, but also the analysis of that data automatic. Each mark in the check sheet indicates a defect. The type of defects , number of defects and their distribution can be seen at a glance, which makes analysis of data very quick and easy. Check sheet provides a logical display of data that are manually derived and yield results from which conclusions can be easily drawn.

3.CONTROL CHART:

A control chart is a simple graph or chart with time on the horizontal “x-axis vs. the quality characteristics measured on a vertical “y” axis with the control limits for the quality characteristics measured. In other words , a control chart is a continuous graphic indication of the state of a process with respect to a quality characteristic to be measured. In the case of performing the final inspection off garments. You go out on the production floor and just before shipping pull a number of samples, inspect them, and note the number of defects and calculate percent defective for several days. The result may look something like the following:

No: of samples inspected	No: of Samples Defective	% of defective
392	14	3.6
346	10	2.7
132	2	1.5
141	6	4.2
344	2	.6
170	7	4.1
164	0	0

Variations or fluctuations in data are generally caused by a large number of small differences in materials, equipments, the surrounding atmospheric conditions, physical and mental reactions of people involved etc. These small differences cause data to fluctuate or vary in a manner called “normal “ or “random” and such variations are termed normal variations . In other words, these are variations normal to the process

Occasionally, however there will be a large or unusual difference, much more important than all those small differences put together. For example , material is taken from a different lot, the machine setter makes a new setting, an inexperienced operator takes the place of an experienced operator. These large differences cause changes in a process resulting in variation in the characteristics measured in a manner called “abnormal” and these variations are called abnormal variations.

It is possible to detect this difference or to make this distinction using a statistical tool known as the control chart. Abnormal or unnatural variations have identifiable, assignable causes. This makes the diagnosis and correction of many production troubles and often brings substantial improvements in product quality and reduction in scrap and rework. So by identifying certain quality variations as

having no assignable causes or being natural to the process, the control chart tells us when to leave a process alone and thus prevents unnecessarily frequent adjustments that tend to increase the variability of the process rather than decrease it.

4. FLOW CHART:

A flow chart is a schematic diagram of a process including all the steps or operations in the sequence as they occur. The logic here is that the act of constructing a flow chart will help to clarify various steps involved in a process and result in a better overall understanding of that process. One must understand a process clearly to be better able to identify and solve its problems. Flow chart can help to understand the complete process, identify the critical stages of a process, locate problem areas and show relationships between different steps in a process

5. HISTOGRAM:

A histogram is a bar chart or bar graph. It is a graphical depiction of a number of occurrences of an event. A histogram simply shows the distribution of sample

data and gives some idea about the variability of that data. Histogram is a graphic summary of variation in a set of data, and is a simple but powerful tool for elementary analysis. A histogram can help understand the total variation of a process and quickly and easily determine the under laying distribution of a process.

6. PARETO CHART:

A Pareto chart is nothing but a histogram where a number of occurrences of an event are arranged in descending order. The quality defects are unequal in frequency , that is when a long list of defects are arranged in order of frequency, generally relatively few of the defects account for the bulk of defectiveness. Thus Pareto chart helps to identify those defects that cause most problems and by addressing those defects, most of the quality problems can be solved and improvement be made. So in this instance , it would be most effective to address fabric quality first because any improvement in fabric quality will significantly improve overall quality of the product.

7. SCATTER DIAGRAM:

A scatter diagram is a plot of one variable vs. another variable, which is dependent on the first variable. For example yarn twist may depend on the twists per inch ; moisture absorbency in a fabric may depend on fabric thickness and so on . By plotting one variable against another , it may or may not become obvious how they are related, in other words, a pattern may or may not become obvious how they are related, in other words, a pattern may or may not emerge. Various possible patterns of a scatter diagram.

LEVELS OF STANDARDS

 

There are various levels of standards

1. Company standards: These standards are useful to the company’s design , development, production , purchasing and quality control departments. These standards may be those developed by some other organizations and adopted by the company as it owns standards
2. Industry Standards: These standards are typically developed by a trade association or professional society . For example, American Chemical Society has for amny years maintained specifications for chemical reagents
3. Government Standards: These are standards either developed by the government or developed by some other organization and adopted by the government. The government standards generally tend to be related to safety or well-being of the people.
4. Full consensus Standards: These are standards developed by the representatives of all sectors, such as industry, consumer, government, academia, whohave an interest in use of these standards either as a producer or consumer.

Sources of Standards:

Various standards developing organizations such as American Society for Testing and Materials (ASTM), American National Standards Chemists and Colorists (AAtCC), American National Standards Institution (ANSI), British Standards Institute (BSI), International Standards organization (ISO) etc are the largest sources of standards.

American Society for Testing and Materials:

ASTM is a non profit organization that provides a forum for producers, users, ultimate consumers and those having a general interest to meet on common ground and write standards for materials, products, systems and services. From the work of 132 standards – writing comities, ASTM publishes standard test methods, specification, guides, classifications and terminology. ASTM’s standard development activities encompass metals, paints, plastics, textiles, petroleum,construction,energy the environment , consumer product, medical services and other areas

American Association of Textile Chemists and Colorists:

Founded in 1921, the American Association of textile chemists and colorists ahs grown from a group of 270 charter members into world’s largest textile chemistry membership society,with close to 7000 members in the U.S and 6o countries.AATCC is a source of test methods in areas of colorfastness,wetprocessing,fibre identification and textile chemistry .AATCC has published more than 175 test methods in these areas, which are contained in AATCC’s Technical Manual published every year.

American National Standards Institute (ANSI):

The ANSI has served in its capacity as administrator and coordinator of the United States private sector voluntary standardization system for 78 years. The Institute represents the interests of its nearly 1400 company, organization, government agency, institutional and international members.

The Institute ensures that its guiding principles,consensus,due process and openness are followed by more than 175 distinct entities currently accredited under one of the federations three methods of accreditation(organization, committee or canvas)

British Standards Institution:

British Standards Institution was founded in 1901 to coordinate the development of national standards . The BSI was incorporated by Royal Charter in 1929. A non-profit disturbing organization, BSI remains independent of government , industry or trade associations.

International Organization for Standards:

The International Organization for Standards is a worldwide federation of national standards bodies from some 100 countries, one from each country. ISO is an non-governmental organization established in 1947. The mission of Iso is to promote the development of standardization and related activities in the world with a view to facilitating the international exchange of goods and services and to developing cooperation in the sphere of intellectual, scientific, technological and economic activity. ISO’s work results in international agreements which are published as International Standards.

“Total Quality Management” is an enhancement to the traditional way of doing . business. It is a proven technique to guarantee survival in world class competition. Only by changing the actions of management with the culture and actions of an entire organization be transformed. TQM can be defined as follows

Total= Made up of the whole

Quality= Degree of excellence of a product on service provided

Management= Act, art of manner of handling, controlling etc

Therefore TQM is the art of managing the whole to achieve the excellence.

TQM is defined as both a philosophy and a set of principles that represent the foundation of a continuously improving organization. It is the application of quantitative mehods and human resources to improve all the processes within an organization and exceed customer needs now and in future. TQM integrates fundamental management techniques, existing improvement efforts, and technical tools under a disciplined approach.

Four P.I s of TQM:

The four important pillars or elements of TQM are:

• Involvement of all the employees
• Proper control of all processes
• Customer satisfaction
• Continuous improvement

The six basic concepts of TQM are:

• Management commitment
• Customer Satisfaction
• Employee involvement
• Continuous Process Improvement
• Supplier Partnership
• Performance Measurement

Management Commitment:

Management should be committed to improve the quality at all levels , for which the “leadership qualities” have to be imbibed by the Chief Executive Officer. The characteristics of a quality leader are:

1. § To give priority o internal and external customer’s needs
2. § To empower subordinates
3. § To emphasize improvement
4. § To emphasize prevention of defective product
5. § To train and coach the employees and not direct and supervise them
6. § To learn from problems
7. § To communicate to everyone about TQM
8. § To continuously demonstrate improvement in quality
9. § To choose quality suppliers
10. § To implement QMS effectively
11. § To encourage and recognize team effort

To start the implementation of TQM, a “Quality Council” has to be formed comprising of the CEO, Senior managers of different departments like Design, Marketing, Finance, Production and Quality Control , a Coordinator or consultant who may be from outside and representative of Labour Union. The functions of the quality control are:

1. To develop a quality policy statement
2. To develop a long term quality improvement programmes
3. Create total education and training plan
4. Determine and monitor costs of poor quality
5. Determine performance measures in different departments
6. Devise recognition and reward system for employees

Customer satisfaction:

Customers are the most important asset of any organization’s success depends on how many customers it has. Increasingly, manufacturing and service organizations are using Customer Satisfaction as a measure of quality. Total quality management aims at meeting or exceeding customer satisfaction. Customer satisfaction is known by getting feedback from the customers, through questionnaires, rating scales, toll-free telephone services, customer meets or visits, report cards, internet, employee feedback etc.

Customer satisfaction is not” objective”, but more of subjective, which is hard to measure. It is more of a feeling or attitude. James teboul has developed a model, which depicts customer satisfaction.

Employee involvement:

Involving the employees is one approach in improving quality and productivity. Only by motivating the employees, can employees be made to get involved in the functioning of the organization . Inorder to understand how an individual can be motivated, we have to understand “Maslow’s Hierarchy of Needs”. He has stated that motivation can best be explained in terms of a hierarchy of needs and there are five levels in it. These levels are survival, security, social, esteem and self-actualization. Once the lower level is satisfied, it can no longer motivate a person. Therefore, in order to motivate that type of a person, the second level has to be concentrated and so on.

Employees will be motivated by appreciation, good pay, promotion, good working conditions etc. The benefits of getting the employees involved in the functioning of the organization are:

1. Their expertise can be shared by the organization
2. Any change can be easily implemented and any corrective and preventive actions easily
3. The morale of the employees will improve
4. The organization can easily achieve its goal

Continuous Process Improvement:

It is a known fact that “perfection” is near impossible. To achieve perfection, improvement is necessary. Improvement is made by adopting the following methods.

• Viewing all work as process
• Making all processes effective and efficient
• Anticipating Customer needs
• Controlling in-process performances
• Eliminating waste and re-work
• Bench marketing
• Innovating

The 5Ms (Men, Machine, Money, Materials, & Management) constitute the input. Using the process, the product is manufactured. The feedback from the customer is got, and based on the discrepancies pointed out by him, corrective and preventive action is taken, i.e, continuous improvement is made in the process of manufacture.

The feedback from the customer is got and based on the discrepancies pointed out by him, corrective and preventive action is taken, i.e, continuous improvement is made in the process of manufacture

Supplier Partnership:

Raw materials constitute about 60% of the cost of a product. Hence the suppliers of a raw material and accessories must be considered as partners of our organization. There must be a long term commitment, trust and a shared vision between supplier and manufacturer , if a quality product has to be produced.

There are some accessories which can be manufactured by us and which can be also sourced from outside suppliers. It can be from a single supplier, or multiple suppliers. Sourcing suppliers from outside is based on the below mentioned criteria

• Criticality of the item
• Organization’s technical expertise
• Availability of supplier
• Supplier’s Management system
• Production capacity
• Price
• Flexibility of production
• Track record etc

“Just in time “concept is a very important concept as for as sourcing is concerned. Just in time means procuring the right raw materials or accessories only at the right quantity and at the right time only. This would reduce the inventory cost. The lead time is very important to implement “just in Time Inventory Control”

If the following measures can be sincerely followed, an effective manufacturer supplier partnership can be maintained:

1. Suppliers should be considered as very important for maintaining quality of products
2. Both manufacturer and supplier must respect each others independence
3. The requirements of raw materials or accessories have to be clearly laid
4. A contact has to be made for quality, quantity, price, delivery methods, payments etc.
5. Supplier should provide all data regarding his quality control
6. A product quality evaluation method has to be formulated with the supplier
7. Dispute settlements have to be clearly spelt out.
8. There must be exchange of information regarding product improvement and quality by supplier to manufacturer
9. A good relationship has to be maintained with the supplier, other than in business
10. Every move has to have the ultimate customer in mind.

Performance Measures:

Organizations must manage by “Facts” and not by “Gut Feelings”. That is organizations must take decisions based on the statistical figures and analysis and not based on a vague judgments. Each organization must develop performance measures to have factual data regarding, production, wastage, quality, etc. The areas in which performance measures have to be studied has to be decided at first. Some of the areas in which performance measures can be done are:

• § Human Resources
• § Customer complaints received
• § Production
• § R & D
• § Suppliers service ratings
• § Marketing and sales
• § Administration

The objectives of introducing performance measures are:

• 1. To establish baseline standards and reveal trends
• 2. Determine which processes are to be improved
• 3. Indicate process gains and losses
• 4. Compare goals with actual performance
• 5. Provide information for individual and team evaluation
• 6. Provide information to take decisions
• 7. Determine overall organizations performance.

Failure Mode effective Analysis:

“FMEA” is an analytical technique wherein, every component of the product is thoroughly studied for its possibilities of failure and design or other changes made to avoid failure of the components.

It is “Before the event” action and helps us to establish controls and produce a defect free, durable and reliable product, which would exceed the customer expectations. FMEA can not only be done on the product, but can also be done in other areas like Process control, maintainence etc.

The general stages of implementation of FMEA are:

• 1. Specify possibilities of failure
• 2. Specify the effect of failure and give priority number
• 3. Specify detailed action plan to rectify it
• 4. Re-evaluate the corrective action.

MANAGING QUALITY THROUGH INSPECTION:

In the beginning, to obtain an overall picture of where you stand in terms of quality, perform 100% final inspection of all styles for at least to to three weeks and collect information. The following are the defects are to look for:

• Broken buttons

• Broken Snaps
• Broken Stitching
• Defective Snaps
• Different shades within the same garment
• Dropped stitches
• Exposed notches
• Exposed raw edges
• Fabric defects
• Holes
• Inoperative zipper
• Loose/hanging sewing threads
• Misaligned buttons and buttonholes
• Missing buttons
• Needle cuts/chews
• Open seams
• Pulled / loose yarns
• Stain
• Unfinished button holes
• Zipper too short

Analyze the data collected from100% inspection. If a pattern of defects emerges, it makes a solution that much easier. If a pattern does not emerge, it means that you have widespread quality problems.

A garment can have more than one defect. Therefore, the number of defects and the number of defective samples is not the same. The most common defect found out is related to buttons. Perhaps, button quality is such that they break in

pressing, may be they are attached so poorly with the slightest stress they come off. A second area of concern here is the fabric defect. Fabric defects can be further analyzed and grouped into various categories of defects such as stains,

slubs, missing picks, dropped stitches etc. A third area of concern should be open seams. But the major problems found are unfinished buttonholes. Significant improvements can be achieved by concentrating on unfinished buttonholes and lining seams

Another major that occur is in the finishing-pressing area. Perhaps some garments are not pressed at all or material handling is such that a number of pressed garments end up wrinkled. In any inspection program it is very important to remember that the inspection program’s primary objective is to obtain information on which necessary actions can be taken. Such actions can be corrective in nature to prevent defective garments, or such actions may reflect a decision to reduce inspection frequency because of the consistently good quality of production. If you use an inspection programmes as merely a failure fixing program or a watchdog to prevent defective garments from reaching you customers.

The inspection program should not merely be a device to separate good from bad. The real value of inspection program lies in what you do with the information that you obtain from this program. The individuals selected for a quality control inspector’s job must have a lot of initiative and be able to work under the minimum supervision. They should also be tactful in dealing with people. Quality control inspectors must not be paid on a piece rate basis, but should be salaried employees. It is not how much they do , but what they do is important.

MANAGING QUALITY THROUGH TESTING:

When one mentions testing to a garment manufacturer, usually the manufacturer envisions a full fledge testing laboratory. However to effectively manage quality of garments, one does not need to have a full fledge testing laboratory. An

effective testing program can include only a pair of washer and dryer .With a washer and dryer one can find out something about shrinkage and colour fastness in laundering, durable press qualities, durability of seams, durability of fusible interlinings, if trimming and accessories will withstand appropriate washing and drying, compatibility of trimmings with the rest of garment in terms of shrinkage and colorfastness and shrinkage of zipper tape.

SYMBOLIC REPRESENTATION OF PEG-PLAN

The next step in describing the fabric design is to specify which harnesses will be lifted and which harnesses will be lowered during each pick in the unit cell of the fabric. This is done using cam draft or chain draft (CD) for cam and dobby shedding. In jacquard shedding, every warp end is controlled individually. CD diagram shows the order of lifting the harnesses and therefore the warp yams since each warp end is attached to a harness.
In CD diagram, the columns represent the harnesses and the rows represent the picks. The picks are numbered from bottom to top as in the case of unit cell; therefore, the heights of the unit cell and the CD are equal. Similarly, the width of CD and the height of DID are equal since they both show the harnesses. To indicate that a harness is lifted during insertion of a pick, the corresponding square in the CD matrix is filled or marked with an "X" as shown in figure. Conversely, a blank square means that the harness is lowered during the insertion of that particular weft. In the figure, harness 1 and harness 4 is lifted during the insertion of the first pick.

 

n practice Design, DID, & CD are combined together as shown in figure.

Such an organization of weave diagram, DID, reed plan and CD gives most of the information for the design and manufacturing of the fabric. The only information missing from this diagram is the selvages. When specifying a fabric, the specifications for the entire warp should be given, including selvages. The DID diagram and reed plan for selvages are constructed similar to the body of the fabric.

FABRIC HISTORY

Tens of thousands of years ago, early humans learned to obtain fibers from wild plants, such as wild flax, hemp, and nettles. Such fibers could be spun into thread and made into cloth textiles. People began to weave fabric during the Neolithic Era, a period that began around 8000 BC. Evidence of early weaving comes from fragments of flax fibers found in Switzerland. In some cultures, people made cloth without weaving, by pounding sheets of bark to produce a soft, flexible textile. The development of agriculture led to the domestication of fiber plants, such as cotton, hemp, and flax. Simultaneously alternative sources of yarn invented from natural, animal, mineral, chemical sources.

They are: -

• · Animal base - from sheep, rabbit, silkworm - wool, silk etc…
• · Mining of minerals - asbestos, glass etc…
• · Chemical - synthetics origin - Nylon, Polyester etc...

These fibers are converted into yarns by menace of spinning and then woven / knitted to produce fabric. The following is the history of the fabric, which is classified according to the manufacturing technology.

Ø History of weaving:

Fabric can be made in a variety of ways, such as knotting, knitting, and braiding, but most cloth is made by weaving. Weaving is usually done on a loom that holds long threads (the warp) under uniform tension so that other threads (the weft) can be inserted over and under them. Many different types and patterns of weaving are possible, depending on the fiber used and the arrangement of the threads. Ancient Egyptians wove their earliest textiles from flax, which produced linen; in southern Europe, the earliest textiles came from wool; in China, from silk; and in India, Peru, and Cambodia, from cotton

Fabric is woven with the help of machine called Loom. Weaving is an ancient technology to make cloth primarily for protection from weather and later on for wearing purposes. This technology is originated from weaving on handlooms. In the modern era, manufacturing of fabrics started with power looms and subsequently with hi-tech / sophisticated looms called shuttle less weaving machines.

NATURAL FIBERS

History of the principal natural fibers used in textiles for apparel and home fashion and the growth is as follows.

EST. DATE	FIBER	BACKGROUND AND PRODUCTION
5,000+ BC	FLAX:	o Generally considered to be the oldest natural textile fiber. o Fine linen was used as burial shrouds for the Egyptian pharaohs o Largest producer: Soviet States; other large producers include Poland, Germany, Belgium and France. Largest exporters are Northern Ireland and Belgium.
3,000+ BC	COTTON:	o Worn by Egyptians earlier than 2,500 BC. o Eli Whitney's invention of the cotton gin in 1793 revolutionized the processing of cotton. o The development of the power loom in 1884 brought significant improvements and variations to cotton fabrics. o Major producers: United States, Soviet States, China and India. Lesser producers include Pakistan, Brazil, Turkey, Egypt, Mexico Iran and Sudan.
3,000 BC	WOOL:	o There are 40 different breeds of sheep, which produce approximately 200 types of wool of varying grades. o Major producers include: Australia, New Zealand, Soviet States, China, South Africa, and Argentina.
2,600 BC	SILK:	o Silk culture began about 1725 BC, sponsored by the wife of China's emperor. o Silk is made from two continuous filaments cemented together and used to form the cocoon of the silkworm. o The Chinese closely guarded secrets of cultivation and fabric manufacturing for about 3,000 years. o India learned of silk culture when a Chinese princess married an Indian prince. o The major producer and exporter of silk is Japan.

Weaving

Weaving is a textile craft in which two distinct sets of yarns or threads are interlaced to form a fabric or cloth. The threads which run lengthways are called the warp and the threads which run across from side to side are the weft or filling.Cloth is usually woven on a loom, a phonethat holds the warp threads in place while filling threads are woven through them. Weft is an old English word meaning "that which is woven A fabric band which meets this definition of cloth (warp threads with a weft thread winding between) can also be made using bad methods, including tablet weaving, back-strap, or other techniques without looms.
The way the warp and filling threads interlace with each other is called the weave. The majority of woven products are created with one of three basic weaves: plain weave, satin weave, or twill. Woven hands can be plain (in one colour or a simple pattern), or can be woven in decorative or artistic , including tapestries. Fabric in which the warp and/or weft is tie-dyed before weaving is called ikat. yapzz:D Though traditional handweaving and spinning remain popular crafts, nowadays the majority of commercial fabrics in the West are woven on computer-controlled Jacquard looms. In the past, simpler fabrics were woven on dobby looms, while the Jacquard harness adaptation was reserved for more complex patterns. Some believe the efficiency of the Jacquard loom,

Process and terminology
In general, weaving involves the interlacing of two sets of threads at right angles to each other: the warp and the weft (older woof). The warp threads are held taut and in parallel order, typically by means of a loom, though some forms of weaving may use other methods. The loom is warped (or dressed) with the warp threads passing through heddles on two or more harnesses. The warp threads are moved up or down by the harnesses creating a space called the shed. The weft thread is wound onto spools called bobbins. The bobbins are placed in a shuttle that carries the weft thread through the shed.

The raising and lowering sequence of warp threads in various sequences gives rise to many possible weave structures:
    * plain weave,
    * twill weave,
    * satin weave, and
    * complex computer-generated interlacings.
Both warp and weft can be visible in the final product. By spacing the warp more closely, it can completely cover the weft that binds it, giving a warp faced textile such as rep weave. Conversely, if the warp is spread out, the weft can slide down and completely cover the warp, giving a weft faced textile, such as a tapestry or a Kilim rug. There are a variety of loom styles for hand weaving and tapestry. In tapestry, the image is created by placing various colors of weft only in certain warp areas, rather than across the entire warp width.
There are some indications that weaving was already known in the Palaeolithic era. An indistinct textile impression has been found at Pavlov, Moravia. Neolithic textiles are well known from finds in pile dwellings in Switzerland. One extant fragment from the Neolithic was found in Fayum, at a site dated to about 5000 BCE. This fragment is woven at about 12 threads by 9 threads per cm in a plain weave. Flax was the predominant fibre in Egypt at this time and continued popularity in the Nile Valley, even after wool became the primary fibre used in other cultures around 2000 BCE. Another Ancient Egyptian item, known as the Badari dish, depicts a textile workshop. This item, catalogue number UC9547, is now housed at the Petrie Museum and dates to about 3600 BCE. Enslaved women worked as weavers during the Sumerian Era. They washed wool fibers in hot water and wood-ash soap and then dried them. Next, they beat out the dirt and carded the wool. The wool was then graded, bleached, and spun into a thread. The spinners pulled out fibers and twisted them together. This was done either by rolling fibers between palms or using a hooked stick. The thread was then placed on a wooden or bone spindle and rotated on a clay whorl, which operated like a flywheel.
The slaves then worked in three-woman teams on looms, where they stretched the threads, after which they passed threads over and under each other at perpendicular angles. The finished cloth was then taken to a fuller.