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The Computer Aided Design and Computer Aided Manufacturing are the modern innovative technology in garments manufacturing like all other manufacturing sectors. Garments CAD is specially used for pattern designing and marker making. On the other hand CAM is used for fabric cutting and other manufacturing sections. Before implementing those new technologies, manual system was widely used in garments sector. In recent time some large garments factories of Bangladesh are starting to adopt CAD and CAM technology. Beside that a huge number of medium and small size factories are using manual system yet. This paper presents a feasibility study of CAD and CAM technology in above mentioned different size factories in Bangladesh. The Study is carried out in respect of production procedure, required man power, production/hr, product quality, production efficiency, and production cost. The practical investigation and data shows the scenario that all types of garments industries are not capable to use CAD & CAM

and also not even profitable for them

Garments Industries in our country is facing the challenge of export of their

products in the world market. The market has become very competitive and it is

very hard for the poor countries to survive in the quota free market. Efficient

management and proper business strategies can produce quality production in

minimal time and costs. Computerization is a tool to achieve this goal which

allows the best use of the information to make future plans. Our intension is to

help the garments industries of our country by using proper use of computer

technology. As a reference subject we visited a garments factory named Knit

Concern Group. But we found that Knit Concern Group is using a proper

computerization system for production and inventory management system.

Most of the works are carried out in pen and paper as well as computerized

method. This is fasting of their operations and errors are removed frequently.

Most of the time, they are using various types of software which help to

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improve efficiency of their working management. The current situation is very

modern in the Knit Concern Group in case of computerizations.

Computer-aided design (CAD), also known as computer-aided drafting and

design (CADD), is the use of computer technology for the process of design and

design-documentation. Computer Aided Drafting describes the process of

drafting with a computer. CADD software, or environments, provides the user

with input-tools for the purpose of streamlining design processes; drafting,

documentation, and manufacturing processes. CADD output is often in the form

of electronic files for print or machining operations. The development of

CADD-based software is in direct correlation with the processes it seeks to

economize; industry-based software (construction, manufacturing, etc.)

typically uses vector-based (linear) environments whereas graphic-based

software utilizes raster-based (pixelated) environments.

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CADD environments often involve more than just shapes. As in the manual

drafting of technical and engineering drawings, the output of CAD must convey

Information, such as materials, processes, dimensions, and tolerances, according

to application-specific conventions.

Computer-aided manufacturing (CAM) is the use of computer

software to control machine tools and related machinery in the

manufacturing of work pieces. This is not the only definition for

CAM, but it is the most common; CAM may also refer to the use of a

computer to assist in all operations of a manufacturing plant,

including planning, management, transportation and storage. Its

primary purpose is to create a faster production process and

components and tooling with more precise dimensions and material

consistency, which in some cases, uses only the required amount of

raw material (thus minimizing waste), while simultaneously reducing

energy consumption.

CAM is a subsequent computer-aided process after computer-aided

design (CAD) and sometimes computer-aided engineering (CAE), as

the model generated in CAD and verified in CAE can be input into

CAM software, which then controls the machine tool.

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Today every coming generation is more fashion conscious so there is

huge demand for new-fangled weave designs. With these conditions

designers have difficulty in keeping pace with the fast changing

trends of the market. Sometimes they find that they are not ready to

cater the market needs. It is not easy to them to remain competitive,

by merely depending upon the traditional way of designing, because

today’s design becomes out of fashion tomorrow. Hence they loose a

share of market, so to keeping pace with fast shifting trends of market

computer aided designing and manufacturing is very much required.

It is well known phenomenon that human being is always in search of

opportunities related to saving money, time and comfort. Any textile

industry will think in terms of improving the efficiency, maximum

utilization of resources and improvement in services for customer’s

satisfaction. Search of these elements leads towards development and

use of new technologies. As the proverb says “Creativity is one

percent inspiration and ninety-nine per cent perspiration.” but

computers have confirm it wrong. They have made textile designing

simpler, faster, more precise and enjoyable. The designer can create

his motifs with a mouse or pen. Once the design is created, further

process of editing the design i.e. clipping of certain parts, adding new

shapes, changing the shapes, distortion, resizing, recolouration, color

reduction, replicating and combining as per the need can be done at

the minimum possible time. Also, one part of design can be altered

without affecting the rest.

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The other benefit is its wide application in different types of fabric

designing. CAD system can be effectively used for designing Suiting/

Shirting, Sarees, Furnishing and Upholstery Fabrics, Blankets, Terry

Towel, Carpet, Labels, Knitwear, Bed Covers, Velvet and other.

Various complicated weaves can be made easily, one need not to

worry about the complicated drafting and peg plans, and the effect of

supposed weave can be seen immediately before actual production.

Shorter design time

Database availability

New capabilities

Example: Focus more on product ideas

Improved product quality

Reduced P

Higher Productivity

Reduced Design Time

More Accurate Designs

Less Time Required for Modifications

Repeatability

Precise

3D detailed drawing

Computerized model to scale

Test without having to produce it

Drawings are device independent

You can resize easily by using calculation

More economical and efficient

Smaller files than bitmapped images

Easier to see the characteristics

You can see the image in animation so you can get the feeling

of it without having to build it the advantages are that fast

smooth quick works fine.

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CAM Advantage: Very fast setup of machinery for large volume

production runs.

1: Difficulty keeping track of changes when many people are working

on drawings for a project (Revision Control).

2: Protecting your ideas is difficult when you must share your

drawings with customers and contractors, but you need input about

design questions (Intellectual Property).

3: Sharing your drawings with other companies who may not be using

the same CAD programs.

1: Potential for wasted parts and materials due to inaccurate CAD.

2: Machinery can break down, halting production.

Devices performing high-tech services in the apparel industry are commonly

referred to as ‘CAD/CAM’. In the apparel industry, CAD systems are mainly

used in various processes such as garment design, pattern preparation, pattern

grading and marker making. CAM systems include computerised sewing

machines, fabric spreading & cutting systems, and mover systems used during

the sewing process of apparel production.

While computerised sewing machines, spreading systems, cutting machines

and mover mechanisms provide a highly technological support during the

production phase, CAD systems are extensively used during the preproduction

phase, which is labour-intensive .

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During the design and production phases, CAD/CAM systems indirectly

improve the productivity and efficiency of companies by contributing to the

integration and automation processes. CAD/CAM constitutes the technological

infrastructure of the concept of ‘CIM’, which has been described as ‘the factory

of the future.

Cad fabric spreader Optical CAD machine

Cad/cam fabric cutter

Cad laser cutting

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Cad fusing machine

CAD is an important industrial art extensively used in many

applications, including automotive, shipbuilding, and aerospace

industries, industrial and architectural design, prosthetics, and many

more.

CAD may be used to design curves and figures in two-dimensional

(2D) space; or curves, surfaces, and solids in three-dimensional (3D)

objects.

CAD is also widely used to produce computer animation for special

effects in movies, advertising and technical manuals. The modern

ubiquity and power of computers means that even perfume bottles and

shampoo dispensers are designed using techniques unheard of by

engineers of the 1960s. Because of its enormous economic

importance, CAD has been a major driving force for research in

computational geometry, computer graphics (both hardware and

software), and discrete differential geometry.

The design of geometric models for object shapes, in particular, is

often called computer-aided geometric design (CAGD).

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Besides CAD software is use for pattern making, pattern designing

and grading. This system contains fully automatic patterns design,

formula Patterns design & free design. The automatic & formula

design model can automatically grade. The graded pattern can be

modified in patterns system without grading again. Reading graded

patterns by digitizer, point grading, line grading, modify patterns and

so on.

Some used are describe in below-

The digitizing software enables you to digitize complete models,

single pieces or only partial lines or curves. Once data is entered, it is

readily available in cad.assyst. There are no restrictions or sequences

to follow -- digitizing direction, number of points or other

conventions is flexible and simple, which frees you to concentrate on

more critical work.

One of the system's important strengths is its ease of use. You will

appreciate the professional, familiar tools the software provides.

Functions, data, and process-enabled steps are easily identifiable

through the friendly and intuitive interface. "Smart" information about

the piece and its relationship to other pieces, styles and markers is

readily available through powerful underlying data-storage

capabilities. cad.assyst detects user errors early, preventing loss of

time and profit.

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With the cad.assyst quality control features, you can use any

measurement function while using other modification functions to

calculate measurements easily and quickly. Powerful features like

pattern mirroring streamline the development process.

Assyst-Bullmer Inc. offers you the option to choose the type of

grading you prefer. You can grade using standard x/ y and distance

grading within rule tables. Or you can take advantage of our powerful,

integrated functionality that enables visual, direct modifications to

pattern shapes on individual sizes. All modifications are automatically

recorded in the grade table. There are no size display limitations.

Piece grading is automatically recalculated whenever a piece is

modified, scaled, mirrored, rotated or split. Using the flexible measure

grading function, you can easily measure and compare the graded

lines and curves of multiple pieces.

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In the garments section cam software is used in widely process. Some

uses are given below-

Speed up the development process by providing tested, proven

development paradigms.

Reusing design patterns helps to prevent subtle issues that can

cause major problems, and it also improves code readability for

coders and architects who are familiar with the patterns.

Design patterns provide general solutions, documented in a

format that doesn't require specifics tied to a particular problem.

In addition, patterns allow developers to communicate using

well-known, well understood names for software interactions.

Common design patterns can be improved over time, making

them more robust than ad-hoc designs

A standard solution to a common programming problem enable

large scale reuse of S/W

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Garments Industries in our country is facing the challenge of export of their

products in the world market. The market has become very competitive and it

is very hard for the poor countries to survive in the quota free market. Efficient

management and proper business strategies can produce quality production in

minimal time and costs. Computerization is a tool to achieve this goal which

allows the best use of the information to make future plans. intension is

to help the garments industries of our country by using proper use of

computer technology.

Current system has many problems. In this section we discuss those

problems

• Production section of the is doing the work manually.

• All the works are carried out in pen and paper.

• Sometimes administrator cannot get proper information about the product.

• Buyers cannot place the order easily.

• This system is not efficient and takes long time

The goal of our project is to make the entire system efficient and user friendly

to the product manager and administrator. The objectives focusing on our

attempt are mainly concerned

• To increase the flexibility of the administrator, agents and buyers.

• Making the system faster than the present system.

• To eliminate the paper work of the agent.

• To facilitate the Administrator so that he can easily access product

information from anywhere.

• To reduce complexity of the production section.

• To reduce physical labor of the personnel

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• To reduce workers

Early engineering drawings were often works of art. Like contemporary

penmanship, this is a skill that few retain. Permanent drawings were often

made with ink. An initial drawing was done using a pencil, T- square, triangles,

scales, irregular (French) curves and drawing instruments such as compasses

and dividers. Early drafting text books spent pages describing how to sharpen

pencils and how to hold them to obtain an even line.

Once the pencil drawing was done, a sheet of tracing cloth would be tacked or

taped over the original drawing. Each line would then be copied using pen and

ink. Particular attention was always paid to lettering on the drawing. Over the

years, various templates and other devices were introduced that enabled

drafters to produce consistent quality lettering. Perhaps the most commonly

used device was the Leroy Lettering Set manufactured by Keuffel & Esser. The

set consisted of several templates of various sizes and a pen device that

followed the shape of the letter in the template and reproduced that character

in ink on the drawing. The company sold a variety of templates with different

fonts.

Another major advance was a device called a Universal Drafting Machine as

shown in Figure This device basically combined the T-square, triangles,

scales and protractor. It enabled the drafter to create perpendicular lines at

any orientation. Among the manufacturers were Universal Drafting Machine

Company, Frederick Post, Bruning, and Keuffel & Esser. The latter two are of

particular interest in that they subsequently attempted to develop CAD system

businesses selling mid-priced systems. Both lettering templates and drafting

machines are still sold today although it may be hard to find a local dealer.

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Figure Universal Drafting Machine

Eventually, different engineering disciplines developed their own methods and

approaches to engineering design and drafting. Architects had a style that was

applicable to their work but was much different than what aeronautical

engineers used. A major problem in the latter case was the need to produce

accurate drawings at scale for large components of an airplane since it was

not possible to convert smaller drawings into the templates needed to produce

these parts. Figure shows several engineers and technicians creating a

aircraft master layout.

During the decades following the Second World War, drafting equipment

suppliers introduced a variety of materials to improve the productivity of the

drafting process. Instead of drawing every detail on a drawing, stickers

representing these items could be applied to the drawing. Together with a new

generation of reproduction machines, the time to create routine drawings was

reduced substantially.

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Figure Creating an Aircraft Master Layout

Calculations were typically done with slide rules, electromechanical desk

calculators and handbooks of mathematical tables and engineering data. Many

technical calculations were done using logarithms which enabled multiplication

and division calculations to be done using addition and subtraction. The most

popular handbook for doing these calculations was first published in by

Dr. Richard Burington. Unfortunately, these handbooks often contained minor

errors. Burington’s handbook was reprinted numerous times, each with

corrections from prior editions.

The engineering design process, including the preparation of drawings, was

fraught with opportunities for error. One result was that every calculation and

drawing was checked multiple times, especially when the consequences of an

error could be disastrous. While computers have taken much of the drudgery

out of engineering design, we know they are not perfect and it is still possible

to make horrendous mistakes if one does not exercise the appropriate levels of

care.

Americans were first who begging automate processes in light industry. They

create automate cutting device (ACD) for cutting material flooring by special

knife over the ordered program without previous marking. The path to wide

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spread using was not very easy. The developers over 5 years persuade

entertainments of light industry in effectiveness of their method. Once they

persuaded automobile entertainment to try cutting device to cut material for

car seat covers. Results surpassed all expectations. After this case some

entertainments in garment industry start to use cutting device. Very important

that many present-day CAD Systems very similar to American system “Gerber”.

In USSR the first CAD System for light industry was jointly developed by

specialist of Department mathematical and optimal projecting of Institute

machine-building problem in Ukraine Academy of Science and Research and

developing bureau of automated control systems for textile and light industry

in Moscow. The system was developed on the base of ARM SM-4.

Specialist of Institute machine-building problem developed software for

projecting markers.

Specialists of Research and developing bureau developed Automate Cutting

Device (ACD) for cutting by laser beam.

In 1988 year software was demonstrated at Federal Exhibition Center in

Moscow. CAD System was regarded by “Gold medal” because of realized

program of automatically projecting marker surpass all well-known CAD

System in the world.

This software serves the necessary need but didn’t become wide spread

because of using ARM SM-4 which were only 2 units in USSR for light industry.

A wide developing of CAD Systems starts in 1990 years with spreading of IMB

PC computers.

The first commercial applications of CAM were in large companies in the

automotive and aerospace industries for example UNISURF in 1971 at Renault

for car body design and tooling. [Citation needed]

Originally, CAM software was seen to have several shortcomings that

necessitated an overly high level of involvement by skilled CNC machinists.

Fallows created the first CAM software but this had severe shortcomings and

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was promptly taken back into the developing stage.[citation needed] CAM

software would output code for the least capable machine, as each machine

tool control added on to the standard G-code set for increased flexibility. In

some cases, such as improperly set up CAM software or specific tools, the CNC

machine required manual editing before the program will run properly. None

of these issues were so insurmountable that a thoughtful engineer or skilled

machine operator could not overcome for prototyping or small production

runs; G-Code is a simple language. In high production or high precision shops, a

different set of problems were encountered where an experienced CNC

machinist must both hand-code programs and run CAM software.

CAD had its origins in three separate sources, which also serve to highlight the

basic operations that CAD systems provide. The first source of CAD resulted

from attempts to automate the drafting process. These developments were

pioneered by the General Motors Research Laboratories in the early s.

One of the important time-saving advantages of computer modelling over

traditional drafting methods is that the former can be quickly corrected or

manipulated by changing a model's parameters. The second source of CAD was

in the testing of designs by simulation. The use of computer modelling to test

products was pioneered by high-tech industries like aerospace and

semiconductors. The third source of CAD development resulted from efforts to

facilitate the flow from the design process to the manufacturing process using

numerical control (NC) technologies, which enjoyed widespread use in many

applications by the mid- s. It was this source that resulted in the linkage

between CAD and CAM. One of the most important trends in CAD/CAM

technologies is the ever-tighter integration between the design and

manufacturing stages of CAD/CAM-based production processes.

The development of CAD and CAM and particularly the linkage between the

two overcame traditional NC shortcomings in expense, ease of use, and speed

by enabling the design and manufacture of a part to be undertaken using the

same system of encoding geometrical data. This innovation greatly shortened

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the period between design and manufacture and greatly expanded the scope

of production processes for which automated machinery could be

economically used. Just as important, CAD/CAM gave the designer much more

direct control over the production process, creating the possibility of

completely integrated design and manufacturing processes.

The rapid growth in the use of CAD/CAM technologies after the early s

was made possible by the development of mass-produced silicon chips and the

microprocessor, resulting in more readily affordable computers. As the price of

computers continued to decline and their processing power improved, the use

of CAD/CAM broadened from large firms using large-scale mass production

techniques to firms of all sizes. The scope of operations to which CAD/CAM

was applied broadened as well. In addition to parts-shaping by traditional

machine tool processes such as stamping, drilling, milling, and grinding,

CAD/CAM has come to be used by firms involved in producing consumer

electronics, electronic components, molded plastics, and a host of other

products. Computers are also used to control a number of manufacturing

processes (such as chemical processing) that are not strictly defined as CAM

because the control data are not based on geometrical parameters.

Using CAD, it is possible to simulate in three dimensions the movement of a

part through a production process. This process can simulate feed rates, angles

and speeds of machine tools, the position of part-holding clamps, as well as

range and other constraints limiting the operations of a machine. The

continuing development of the simulation of various manufacturing processes

is one of the key means by which CAD and CAM systems are becoming

increasingly integrated. CAD/CAM systems also facilitate communication

among those involved in design, manufacturing, and other processes. This is of

Particular importance when one firm contracts another to either design or

produce a component

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Evaluation Research aims to demonstrate to what extent previously

stated targets have been reached within the unity of the research by

trying to determine the relationship among input, output, process

and performance variables in the studies being carried out.

Considering the fact that this research includes analytic assessments,

the Evaluation Survey Methodology was chosen, as it is the most

suitable method for the objective direction, application studies and

data evaluation of the research. Technical drawings and size set

tables of the basic t-shirt which form the material of this research

were prepared by the author. These technical drawings are

proportional and equipped with necessary measurements, sewing

instructions and fabric varieties for the preparation of garment

patterns.

Two methods were applied to obtain the findings in the research, the

manual method and the CAD method. Then, the stages for carrying

out the research were determined. On this basis the procedures

forming the research were also established [18]. These were

determined separately for the manual and CAD working methods.

Either of the two procedures stated below can be followed to work

the model with the CAD system:

1- Digitizing the main size patterns after preparing them manually,

2- Preparing from the beginning of the main size patterns using CAD.

To follow the latter procedure, CAD system operators have to be

good pattern designers at the same time. This is not a frequently

encountered situation in the apparel industry. Mostly, the main size

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patterns are prepared manually and then digitized by following the

former procedure in the industry.

Table 1. Stages and procedures for the manual working method.

Numbe

r

Stages Procedures

of stage

1.

Main size pattern

preparation -

Main size pattern checking

and

A. Measurement check

2.

B. Checking of face to face sewing

places

correction

C. Main size pattern correction

Putting necessary

allowances on

A. Production gathering allowances

3. B. Shrinkage allowances

patterns

C. Seam allowances

4.

Main size pattern size

setting -

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5.

Size set patterns check and

correction

A. Measurement check

B. Checking of face to face sewing

places

C. Correction of size set patterns

A. Separation of sizes of nested

patterns

B. Cutting of patterns on

transparent papers

C. Checking of patterns on

transparent papers

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Arrangements prior to

marker making

D. Correction of patterns on

transparent papers

E. Transferring patterns on

transparent papers to

cardboard

F. Checking the patterns on

cardboard

G. Correcting the patterns on

cardboard

H. Cutting the patterns on

cardboard

7.

Marker making and

correction

A. Fabric and rib marker making

B. Checking and correcting fabric

and rib marker

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8. Marker plotting

A. Fabric marker plotting

B. Rib marker plotting

Table 2. Stages and procedures for the CAD system working method.

Numbe

r

Stages Procedures

of stage

1.

Main size pattern

preparation

A. Main size pattern preparation

manually

B. Digitising main size patterns

Main size pattern checking

and

A. Measurement check

2.

B. Checking of face to face sewing

places

correction

C. Main size pattern correction

Putting necessary

allowances on

A. Production gathering allowances

3. B. Shrinkage allowances

patterns

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C. Seam allowances

4.

Main size pattern size

setting -

5.

Size set patterns check and

correction

A. Measurement check

B. Checking of face to face sewing

places

C. Correction of size set patterns

6.

Arrangements prior to

marker making

A. Model file preparation

B. Order file preparation

7.

Marker making and

correction

A. Fabric and rib marker making

B. Fabric and rib marker check and

correction

8. Marker plotting

A. Fabric marker plotting

B. Rib marker plotting

The research was carried out in two directions: In the first direction,

the manual method was compared with the CAD method to

investigate the effects of model complexity. The course steps and

procedures for the model chosen were applied both manually and by

the CAD method. The course steps and procedures for the manual

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method were realized by the author. Those for the CAD method

were realized by an expert CAD system operator.

During the studies carried out in the second direction, the aim was to

com-pare the manual method with the CAD method separately for

each stage value and the total values. At this point only the ‘Model-

’ was handled and related stages and procedures were conducted

times by different expert pattern designers and pattern

technicians, and times by different expert CAD system operators

and operator assistants by using five different CAD systems.

The pattern designers had years of experience in the industry,

and were capable of preparing patterns on all kinds of models. The

pattern technicians chosen had the same level of experience and

expertise as their colleagues in the industry. The CAD system

operators were chosen from among people who had good command

of patterns and the CAD system. The required duties were presented

to both groups in the form of a list of in The pattern designers had

years of experience in the industry, and were capable of

preparing patterns on all kinds of models. The pattern technicians

chosen had the same level of experience and expertise as their

colleagues in the industry. The CAD system operators were chosen

from among people who had good command of patterns and the

CAD system. The required duties were presented to both groups in

the form of a list of instructions by the author, and the work was

carried out under her supervision.

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Two procedures were followed to obtain findings in the research.

The stages and procedures for the manual working method are

shown in Table

Stages and procedures for the CAD working method are shown in

Table

Each course step was timed by a digital chronometer while carrying

out the timing process; human activity and the usage of production

instruments for the person doing the work (or the production

instrument being used) were also taken into consideration [

Based on these usage times and activities, timings were also taken

for the ‘Main Activity’ and ‘Alternative Activity’, & the ‘Main Us-age’

and ‘Alternative Usage’.

The concept of production loss is often expressed in terms of losses

suffered due to a failure to obtain appropriate and profitable returns

from the investment. The three kinds of losses experienced in

industrial establishments are losses in work power, production

activities, raw materials and accessories [

Similar losses are also observed in the apparel sector. The share of

raw materials and accessories, which are the main items of the

apparel industry, reaches of production costs. These losses

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suffered in the apparel industry are pieces called ‘waste and surplus

fabric’, and they often do not have any definite commercial value

Therefore, the effects of the CAD system on the cost of fabric, which

has the greatest share within the total product cost, were also

included into the scope of the research.

For this reason, after the completion of all kinds of work related to

patterns, markers were prepared both manually

Figure Comparison of the manual and CAD methods Figure Comparison of manual and CAD systems.

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The material for this study consists of garment models, patterns, transparent

pattern papers, cardboards, CAD systems, a chronometer and fabrics.

Fashion CAD software is for computerized

pattern making for the apparel and garment manufacturing

industries. Fashion CAD is an integrated suite of software which

includes pattern design, pattern grading, pattern detailing, pattern

layout and a fully featured CAD drafting system. Fashion CAD is an

innovative CAD approach to pattern making which provides the

flexible tools to create and modify pattern designs and to shorten

the time cycle for all pattern making processes, such as grading.

Gerber Technology provides an extensive line of

integrated computer hardware and software systems to the sewn-

goods and flexible goods industries. These systems significantly

improve the efficiency of information management, product and

Sr.# Nomenclature of Equipment/Tools Quantity

1 Systems (computer set) 25

2 Plotters 01

3 Digitizers 02

4 Scales 25

5 Inches tapes 25

6 scissors 12

7 Cutting tables 06

8 Set squares 12

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pattern design, grading and marker making/nesting, material

spreading and cutting processes.

Is software for pattern construction, grading and

lay planning running on standard Personal Computers under

Windows and above. It contains an extensive range of functions

for pattern cutting and modification and is available at a very

competitive price. Therefore, GRAFIS is in use in industry as well as in

trade and education.

PAD System's mission is to offer high technological level

CAD/CAM solutions that are efficient, simple and flexible to all

individuals and companies involved in the apparel, textiles and

leather industry as well as in D computer graphics. PAD System

evolves with its customer. They believe that, through a personalized

approach and by offering continuous first class support and training,

PAD System and its clients will grow together with success.

Lectra is a world leader in the design, manufacturing and

distribution of software and hardware dedicated to the major

industrial users of textiles, leather and other soft materials, supplying

a comprehensive range of associated services for the development of

complete solutions, from product design to manufacture to retailing.

Lectra, a leading technology provider to the fashion industry offers a

wide range of software,

: CAD/CAM/CIM systems are for the Sewn Goods

Industry. TUKA studio is used for Fabric and Garment Design, TUKA

cad for Pattern Design, Grading and Marking.

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Definition of CAD Tools Based on Their

Implementation in a Design Environment

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The production flow chart seen below is used to demonstrate the

stages involved in manufacturing a product using batch production

techniques. The example shows the stages of making the parts for

the picnic table through CAD (computer aided design) and CAM

(computer aided manufacture). Quality control is seen at two stages.

This is when the product is checked for faults as it should be in

perfect condition at each stage.

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32

33

34

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1. Continuous-flow processes. Continuous dedicated

production of large amount of bulk product. Continuous

manufacturing is represented by chemicals, plastics,

petroleum, and food industries.

2. Mass production of discrete products. Dedicated

production of large quantities of one product (with

perhaps limited model variations). Examples include

automobiles, appliances and engine blocks.

3. Batch production. Production of medium lot sizes of the

same product. The lot may be produced once or repeated

periodically. Examples: books, clothing and certain

industrial machinery.

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4. Job-shop production. Production of low quantities,

often one of a kind, of specialized products. The products

are often customized and technologically complex.

Examples: prototypes, aircraft, machine tools and other

equipment.

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1. In manual system the system is used to make maker for garment

making is traditional. But in CAD system marker making is done in

modern system.

2. Marker efficiencies is not visible in manual system. Other hand, marker

efficiency is visible in CAD system.

Manual and Cad Marker Making

3. Marker length is not visible in manual system. Marker length is visible in

monitor screen at CAD system.

4. In manual, once marker is made, not possible to increase its efficiency.

But in CAD it is possible to increase the efficiency at any time.

5. Marker copying is not possible manually. In CAD, by using Plotter as

much as possible copy can be done.

6. Manual marker making is very time consuming method whereas, CAD is

a faster method.

7. In manual system quality cannot be assured. It has quality assurance.

8. Manual system costing is low but CAD is expensive.

38

Before CAD/CAM technology, drafts, calculations and product

design involved pencil, paper and a seemingly endless succession of

blueprints. CAD/CAM's ongoing enhancement has made the process

easier, but with the latest slew of features, some users actually find

less is more.

Virtually every manmade product has been designed and

manufactured using a CAD/CAM program. CAD/CAM, or Computer

Aided Design/Computer Aided Manufacturing, is utilized in every

facet of industry; from designing phones to plotting out toolpaths in

die and mold shops. Although the users of CAD/CAM technology

may, at times, feel frustrated by how often its software is updated, the

fact is that CAD/CAM has close to five decades of history stretching

almost as far back as the computer.

CAD/CAM, like the digital computer, had its inception in the

military. In the mid-1950s the U.S. Air Force began testing an air

defense system known as SAGE (Semi Automatic Ground

Environment) to graphically depict data received on radar systems.

The first computer actually rendering a program, SAGE was

conceived at the Massachusetts Institute of Technology (MIT). In

1960, computer scientists at MIT produced yet another project called

Sketchpad, an application that is now considered to be the first design

program with industrial use. A similar program sprouted up at

General Motors soon after. At that time, mainframes were still large

enough to take up entire rooms.

During the 1960's CAD/CAM technology continued to evolve and

spread to other areas. Automotive companies were the first to adopt

the technology, and used it primarily to design automobile bodies. It

then quickly spread to other sectors of industry, which were only too

eager to abandon traditional pen and paper methods of drafting. By

1973, CAD/CAM was being used to design industrial tools. Midway

through the decade, the 19-inch monitor came out, which meant that

drawings could be viewed larger than the previous standard of 11

inches? In the last half of the 70's, solid modeling software became

available. It allowed users to take "geometric primitives" (basic

39

geometric shapes such as boxes and cones) and combine those using

Boolean operations. In 1982, Autodesk made CAD/CAM history

when it released the first version of AutoCAD, which soon became

the premiere software platform for automobile design.

At times, the history of CAD/CAM seems like the plot of a spy novel.

In 1984, a Hungarian scientist named Gabor Bajor, succeeded in

smuggling two Macintosh computers into his Communist-controlled

homeland. With the intent of writing a 3D CAD program, Bajor and

his teenage assistant used the illegal computers to create just that

program, and started the Graphsoft Company. In 1985, Diehl

Graphsoft introduced MiniCAD to the market, which would be

considered the industry standard for CAD on the Mac. The same year

Autodesk unveiled AutoCAD 2.1. Complete with 3D capabilities,

AutoCAD 2.1 was another breakthrough that transformed design in

the auto industry. In the late 80's and early 90's, CAD/CAM giant

Unigraphics took its place as a major industry player by partnering

with industry powerhouses such as General Motors, UNIX, GE and

Boeing.

During the early 1990s, Unigraphics introduced hybrid modeling,

which featured both traditional modeling and advanced parametric

techniques. By the end of 1994, over one million units of AutoCAD

had been sold, and by the end of 1995, there were about 350,000 users

of generic CAD/CAM reported worldwide.

In 1996, General Motors signed the largest contract in CAD/CAM's

history by selecting Unigraphics as its sole vendor for vehicle

development software. Soon afterwards, Unigraphics would once

again transform the medium by releasing CAD/CAM software that

allowed for the definition, control and evaluation of product

templates.

Another major advance in CAD/CAM occurred IN 1999 when

Think3, a "Johnny-come-lately" to the world of CAD/CAM,

introduced the first mechanical design software that could fully

combine the power of parametric solids, advanced surfacing,

wireframe and two-dimensional drafting on the desktop in one

environment. Subsequently, a plethora of software vendors has

40

surfaced, inundating the market with competing CAD/CAM platforms

AND causing designers to be alternately pleased and confused by the

sheer number of options available to them.

At present, CAD/CAM continues its steady path of progress. Much of

this progress is in the form of refining past innovations to make them

more efficient and user friendly. A groundbreaking CAD/CAM

innovation has not occurred for a number of years, which seems to

indicate that another sweeping change is just around the corner -- or

maybe not.

Despite the advent of 3D CAD/CAM, many CAD/CAM users still

prefer to render designs in 2D. Thus, recent 3D innovations such as

animated "walk-throughs" (a technique that allows designers to

visually move in and around the rendered model, and see it from

every possible angle) are still largely underused. The same is true of

the bevy of collaboration tools currently available to the CAD/CAM

user.

The ability to combine CAD/CAM, with finite-element analysis and

the accessibility of simulation and knowledge management, has yet to

be fully embraced. Perhaps, it is in one of these areas that the next

CAD/CAM breakthrough will occur.

One thing that can be said with a degree of certainty is that research

and development are currently ahead of user demand. When, and if,

the garden-variety CAD/CAM user decides that they need to expand

their range of capabilities, they will find a world of cutting-edge

CAD/CAM tools at their disposal.

Garment manufacturers are primarily engaged in the design, cutting

and sewing of garments from fabric. Bangladesh has become an ideal

land of readymade garments. There are about 4500 garment industries

41

in Bangladesh and 2.5 million people work in this sector. It earns

more than 70% foreign currency from this sector. If we can increase

our export volume, we can earn foreign currency more. Factory can

increase the productivity by using CAD/CAM technology.

Bangladesh using software for shorter development time of sample,

good forecasting of cost, no shrinkage due to spreading including

faster and consistent cutting, better marker efficiency etc. More over

using this technology manufacturer can make sure optimum use of

fabric saving wastage. So production will be increased and production

cost will be reduced. So CAD/CAM technology is a must one for the

garment manufacturer of Bangladesh.

Comparison between CAD system and Manual system

42

Cutting Efficiency (computerized v/s manual)

0

20

40

60

80

100

120

140

NEW PATTERNCREATION

GRADING MARKERPLANNING

SKETCHPREPARATION

MANUAL SYSTEM

0

5

10

15

20

NEW PATTERNCREATION

GRADING MARKER PLANNING SKETCHPREPARATION

CAD SYSTEM

Series 1

43

0

200

400

600

800

1000

1200

1400

TOTAL LENGTH OF FABRIC IN METERS NO Of SHIRT

CAD SYSTEM CUTTING EFFICIENCY

Series 1

Series 2

0

200

400

600

800

1000

1200

1400

TOTAL LENGTH OF FABRICS INMETERS

NO . OF SHIRTS

MANUAL SYSTEM CUTTING EFFICIENCY

Series 1

44

Production Efficiency(computerized v/s manual Sewing)

15000

15200

15400

15600

15800

16000

16200

16400

NO OF SHIRTS PER DAY

Column2

Column3

Column4

Column5

Column6

Column7

Column8

45

Markers quantity per day

per

day

per

day

per

day -->> per month

per

day

per

day

per

day -->> per month

3500

3600

3700

3800

3900

4000

4100

4200

4300

NO OF SHIRTS PER DAY

Series 1

Series 2

Series 3

Series 4

Series 5

Series 6

Series 7

46

Сomparing of fabric consumption:

marker nested manually

,

m

,

m

,

m

,

m

,

m

,

m

automatically by IMM

,

m

,

m

,

m

,

m

,

m

,

m

Fabric

savings on

layer

,

m

, m ~ m ,

m

, m ~ m

Fabric

savings on

layers

, m , m , m , m , m ~ m

Comparing of labor time:

marker nested manually

min.

min.

h

min. min.

h

automatically by IMM

min.. min h 4 min. 40 min. 14

Time savings

min. min. ~ h =

~ days min.

min.

~ h =

~ days

47

Money savings per each month:

m * $ m + h * $ h =

$

m * $ m + h * $ h =

$

Marker Efficiency:

Calculation of marker efficiency is explained below with formula.

General formula using area,

48

, m

, m

49

Time savings

marker nested manually

Automatically by IMM

min.

min.

50

Time savings

51

1: Difficulty keeping track of changes when many people are

working on drawings for a project (Revision Control).

2: Protecting your ideas is difficult when you must share your

drawings with customers and contractors, but you need input

about design questions (Intellectual Property).

3: Sharing your drawings with other companies who may not be

using the same CAD programs.

Potential for wasted parts and materials due to inaccurate CAD.

Machinery can break down, halting production.

To survive in the global market we have to keep in pace with the adventures of

modern generation which demands for Flexible, Dynamic &Versatile

techniques. CAD plays a vital role in textile designing as well as fabric

52

simulation. These possess gives customer satisfaction, on time delivery, variety

in design & color and rapid transmission of design to consumer. It is currently

developing a host of new products. To survive in the global market, the textile

activities in India should be well planned by using ERP system at the core We

wish to conclude by affirming that these control systems, besides improving

the production quality supply all useful indications to establish parameters

like: yarn consumption, fabric unloading, optimization of the material flow, the

organization of maintenance stops, etc would enable fabric & garment

product producers to be dynamically adoptable to the fast and even changing

needs of the fashion oriented “GLOBAL MARKET” place, which is steadily

getting COMPETITIVE.

With the emergence of new global trade environments, alternatives for

production and provision of all sorts of goods have increased and competition

has become fierce. Nowadays the shelf life of a product is not long enough to

justify the time, labour and expense necessary for the design and production

manually. This, in turn, makes CAD extremely important for apparel

production

The increase in the number and the complexity of the models and the decrease

in production time have boosted demands for automatic grading of garment

patterns. Automatic preparation of garment pat-terns using body

measurements obtained from body scanning, and furnishing them with fabric

and production characteristics, will greatly contribute to the dynamic structure

of the apparel sector. Body scanning provides multi-dimensional data that has

the potential to provide new insights into sizing and grading systems. However,

for body scanning to support automated garment development, automatic

integration of measurement data into commercially available CAD/CAM

software must be achieved first.

53

More improvement of the software programmes and training the system

operators on pattern making will enable the main size pattern to be prepared

from draft; the CAD system will thus become more efficient in the main size

pattern stage also. For the CAD system to be more advantageous in the

checking and correcting stages of the main size pattern preparation,

dependence on individuals in CAD functions should be minimised.

Using the CAD system during marker making as efficiently as in other steps

naturally requires the determination of certain standards concerning marker

making. Moreover, improving automatic marker making programmes and

preparing markers using these programmes followed by necessary corrections

will make it possible for the CAD systems to be profitable during these steps as

well. Until this objective is realised, some solutions can be offered;

The system operator must be qualified in the marker making process.

The technician who makes the marker plan and corrections must learn

the CAD system.

Marker makers who prepare the marker plan according to their previous

experience are urged to cooperate and work together with the CAD operator

in charge.

The root of the matter lies not only in the selection of the proper CAD system

according to the type of the firm and the product, but also in the training of

the operators to carry out their functions in the fastest and the most efficient

way, and to improve the work standards within the company. Unpredicted

problems or results encountered in this research could therefore be attributed

to lack of training.

54

The in-service training programmes of the CAD system companies often fall

short of being adequate, because the trainers are not knowledgeable enough

to provide training on pattern making and apparel production; the trainees do

not have the proper background; they are not technically equipped to function

efficiently within the CAD system. Consequently, they fail to reach expected

efficiency targets in using the CAD system. For a lasting solution to this

problem, it is recommended that the cooperation between the universities and

the industrial organizations be promoted in the short term. As a long-term

solution, however, it is essential that comprehensive and relevant training

programmes be developed, especially at the college level, and that the

technicians completing these programmes should be employed in the apparel

industry