1. Following are the common formulas those are used by garment industry professionals.
Formula#1:
Daily Line Target = (Total working minutes in a day X No. of operators in a line X Line eff %) /Garment
SAM
Formula#2:
Individual operator target = (Total working minutes in a day X line efficiency %) /Operation SAM
Formula#3:
Individual operator Efficiency% = (units produced X operation SAM X 100)/Total minutes worked
While you are developing skill matrix for sewing operators, you need measure individual performance.
Secondly, if you plan to start performance based incentive scheme for individual operator, measuring
individual operator efficiency is essential.
Formula#4:
Line Efficiency% = (Line output X garment SAM X 100)/ (Number of operators X minute worked in day)
Note: include helpers and worker doing manual operations in case you have included SAM of those
operations.
Formula#5:
Machine Productivity: Line output / No. of machine used
Machine productivity is measured in production per machine per shift day.
Formula#6:
Labor Productivity = Line output / No. of total manpower (operators +helpers)
Formula#7:
Line WIP (work in process) = Total pieces lie on the line for a particular order line
WIP of the line of an order is equal to Total pieces loaded till date minus Total piece out till date.
Formula#8:
Standard Time = (Observed time X observed rating) + Allowances
Allowances – Relaxation allowance, contingency allowance
Formula#9:
Machine utilization% = (Actual Machine running Time X 100) / Time available
Formula#10:
Cost per minute = Total cost incurred in labor / Total available working minute in a day X no. of labors
Formula#11:
Production Cost per unit = Total cost incurred in production in a day/ no. of garment produced in a day
Formula#12:
Man to Machine ratio = Total manpower of the factory / Total no. of sewing machines (utilized)
Suitable for printing and hanging near your work space when you need to see it most…
2. Two questions are -
1. What is the application of Industrial Engineering in apparel industry?
2. How Industrial Engineering concepts are used by apparel manufacturers?
What is the application of Industrial Engineering in apparel industry?
Industrial Engineering concepts are used in garment manufacturing to fulfill the following purposes -
Monitoring production floor and having better control over the production floor
Improving processes and improving method of working to increase factory's overall performance and
standardized garment manufacturing processes
Overall application of Industrial engineering can be explained better by describing common tasks of the IE
department. Common tasks of an IE department are as following but not limited to these
Work measurement of sewing operations, cutting room jobs and finishing jobs
Setting standard time for sewing operations and manual operations
Style analysis and conducting research and development (R&D) of the styles
Improving method of work and design workstation
Production planning and factory capacity determination
Work aids development
Work station designing and machine layout planning
Labor cost estimation
Performance measuring of workers
Training of workers (sewing operators)
Designing incentive scheme and calculating incentive for sewing operators
Setting line production target of the sewing lines and chasing production from line supervisors and
operators
Application of lean tools
How Industrial Engineering Concepts are used by apparel manufacturers?
Factories those are using IE techniques mostly have a complete IE set up (department). An IE department
consists of an IE managers (in-charge) and Industrial Engineers and juniors engineeTk. The strength of IE
team widely varies based on the maturity level of the department and on the focus of application of
Industrial Engineering. Without having enough team members, an IE department cannot work effectively.
Industrial Engineers are utilized in the following ways but not limited to those -
Factories apply all or few of the above listed functions to
Assist line supervisors by preparing resource requirement plan (machines and equipment and
manpower), line setting and line balancing etc.
assist production managers in target planning and production planning,
help merchandiser and marketing personnel by providing labor cost and production lead time,
help HR department by providing operator performance level, and help in operator recruitment
prepare MIS reports and show management team product status on daily basis and alert management
team if their attention is needed
set up standards operating procedures for new tasks, new process required for ever changing fashion
products
More than the regular jobs, IEs are also responsible for thinking of continuous process improvement.
Initiation of new projects and implementation of the project that has been undertaken, showing the
improvement opportunity within the factory to management team. Engineers are involved in performance
improvement tasks of the cutting department and finishing department.
3. IE Work Flow Chart
Still if you like to know about IE procedures, it can describe with a work flow. Most common tasks of an IE
are presented in an order in the following.
Style analysis --> Make operation breakdown --> Thread consumption calculation--> Making line layout on
paper --> Select m/c and equipment --> arrange guides and attachment -->Planning for production target -->
Setting line when new style is loaded --> Do line balancing --> Record production data --> Make production
reports --> Report to higher management (P.S. This is just an example of work flow).
Most IE tasks are aimed to make better work flow, improve utilization of resources, increasing factory
performance, and reducing production cost. As IE department get matured in a factory, it includes more
tools to help production team to increase the factory performance.
Work flow chart of IE department is shown in the following chart.
4. Implementation Procedure of IE Tools
IE procedure can be explained as the procedure of using Industrial Engineering tools. To learn how
Industrial Engineering tools are used by IEs in garment industry read on the following articles.
Time Study Procedure
Standard Minute Estimation Procedure
Operation Bulletin Preparation Procedures
Operator Training Procedures
Sewing Operator Recruitment Procedure
Thread Average Calculation.
There are two ways to find Cost of Manufacturing (CM) for a particular style/order.
1. Based on Standard Time (SAM) of the product
2. Based on Daily Production Average
1. CM Calculation Based on Standard Time (SAM) of Product Making
To get better accuracy in cost estimation one should prefer this procedure. But too many small size
companies no such resources available to measure product SAM and data for the following parameter Tk.
Following parameters are essential for cost calculation in this method.
1. Product SAM: Standard time of the garment. Standard time of a garment is measured by
using Time Study and using synthetic data.
2. Target Efficiency: Target efficiency percentage is at what % you are expecting running a
specific product and order quantity.
3. Operating Cost per day/machine - Operating cost is factory running cost. Operating costs
are all cost incurred to run the business other than material cost. Calculate monthly operating cost
and then calculate daily operating cost. Calculate per machine operating cost.
Formula:
Cost of Manufacturing = (Operating cost per day per machine* SAM)/(Target Efficiency% * Working hours
* 60)
In the following table an example is shown for calculating manufacturing cost using SAM and Daily
Production figure.
In the above example, garment SAM is 21 minute, target efficiency 60%. So, actual time would be 35
minute to make a garment. Factory works 8 hours in a day and operating cost per day per machine is Tk.
1022.
Cost of manufacturing is Tk. 74.52
2. CM Calculation Based on Daily Production Figure
This method is widely used by garment manufacturing factories. Cost of manufacturing calculation is done
based on historical production data. This is an easier method compared to above one.
Information needed to find Cost of Manufacturing
1. Daily production: Find average daily production of a particular style (garment) based on
earlier (historical) production figures. Calculate daily average production of the factory.
2. Manpower involved in production: How many sewing machines or sewing operators are
utilized to produce above quantity.
5. 3. Operating cost per day/machine: As explained above.
Formula
Cost of Manufacturing = (Operating cost per Day / Total garments to be produced per day)
See the example method -2 in the above table. In the example, daily product is 550 pieces. 40 operators
worked to produce these pieces. Operating cost per machine is Tk. 1022 per day.
So cost of manufacturing is Tk. 74.33
P.S. Data used in the above examples are hypothetical.
Tools and Equipment used by Industrial Engineers
Industrial Engineers (IE) use various type of tools and equipment. What all equipment and tools to
use, depend on the job responsibilities of an IE in a company. Name of the common tools and equipment are
listed below. Purposes of the tools are also mentioned here.
Stop Watch (Digital or analog): Measuring observed time at the time of Time Study.
Measuring Tape: Measuring length of seams and measuring distances.
Digital Camera: Capturing videos for various
operations that help in motion analysis of operations.
Tripod for the camera: Used as camera stand.
Time Study board: Required during time study to hold
the Time Study format.
Calculator: Data calculation and report making.
Tachometer: to measure speed of the motor of sewing
machine. This equipment is used to find machine rpm.
Data capturing and process analysis formats: For
example- Time Study format, Motion analysis format
etc. Data capturing and analysis to bring improvement.
Various documents: Documents are used to assist
production and other processes with information,
methodology or layout. Formats are like Operation
Bulletin, Line Layout, Pitch Diagram, Hourly report
format etc.
Computer: Data analysis, Report making, Mailing, video analysis of operations etc.
6. Standard Hours Earned in Garment Manufacturing
Standard Hours Earned term is not much known in garment factories. Here, Work Study officers
or Industrial Engineers working in garment manufacturing factories (Export house or domestic garment
manufacturing) don't use 'Standard Hours Earned' instead engineers use Standard Minutes produced or
Standard Minutes earned. So when we heard this term first time, we think it might be a different measure.
Let me explain what ‘Standard Hours Earned’ means.
This is similar to Standard Minute Produced by workers. Instead of minutes it is presented in hours. To get
Standard hours earned value, standard minutes are divided by 60. Like, if an operator works for 8 hours a
day and produce garment equivalent to 360 minutes then operator’s standard hours earned would be 6 hours
(This is derived from: 360 minutes/60).
Formula for calculating standard hours earned:
Standard hours Earned = (SAM of operation X Garments produced)/60
This term is also called as Earned Hours because operator has earned that many hours by his/her effort.
Benefit of using Standard Earned Hours
- Easy to compare produced hours against available hours in a day (efficiency)
- Secondly calculating earning amount (in Dollar) of an operator from earning hours is easy as you know
standard hourly rate of your operators.
Operation Breakdown:
Breakdown is a listing of the content of a job by elements. A garment consists of some parts & some group
of operations. Breakdown means to writing down all parts & all process/operation after one another lying
with the complete garment according to process sequence. Prior to defining SAM of the garment, detailed
operation break-down is made by engineer. Both manual and machine operations are included in the
operation list. It is a must to write down the estimated SMV & type of machine beside each & every process.
Breakdown Procedure:
APM, Technician Chief & Work-Study officer must sit together to make breakdown.
Technician breaks the garments into parts and gathered the parts one after another by operation/Process.
Then Work-Study officer & APM fix up the SMV of those operation
By preceding this technique when all process completed need to summarize all process SMV and the
total will be called as respective garment’s SMV.
Benefit of Breakdown:
1. Can see the all operations of the garment at a time.
2. Can anticipate the difficulties of doing critical operation
3. Can make layout in an easy, simple & less time consuming way
4. Can calculate the SMV for target setting & equal time distribution to the operator during layout.
5. Easy to select right operator for right process.
6. Can easily achieve the production target within a very short period.
7. Operation Breakdown and SAM of Full Sleeve Formal
Men’s Shirt
Prior to defining SAM of the garment, detailed operation break-down is made by
engineer. Both manual and machine operations are included in the operation list. Then a
skilled operator is given to do operations one by one. 5 to 10 samples are studied. All
operations are studied by GSD expert for motion analysis. At the same time all
operations are videoed for future reference. Calculated SAM of the operations for a
Formal Shirt has been shown in the following table. This has been defined by a GSD
practitioner of a large size Indian garment export company using GSD software. The
following SAM of each individual operation will help to understand how a shirt’s SAM
reach up to a certain value. The SAM of the operation may vary according to the
changes styling of the shirts, seam length, attachment and work aids used, motion sequence used by the
operator and machine type.
Product: Full Sleeve Men’s Formal Shirt. Brand: Arrow
Total Garment SAM: 22.32 minutes.
Sl. No. Operation List SAM
1 Pinning to profile 0.234
2 Run stitch collar 0.219
3 Trim collar 0.285
4 Clip and turn collar 0.223
5 Crease collar 0.381
6 Top stitch collar 0.42
7 Run stitch (R/s) collar band 0.291
8 Crease collar band 0.317
9 Insert collar in neck band 0.799
10 Turn and crease collar 0.452
11 Attach bias piece to cuff 0.874
12 Crease cuff 0.458
13 Hem cuff 0.501
14 R/s cuff 0.565
15 Trim cuff 0.36
16 Turn cuff 0.527
17 Crease cuff bottom 0.566
18 Attach placket to sleeve 0.795
19 Lock and make diamond 1.026
20 Sew pleats (4 no.) 0.389
21 Hem right front 0.494
22 Attach front placket 0.603
23 Crease pocket 0.542
24 Hem pocket mouth 0.28
25 Attach pocket to front 0.861
26 Attach brand label and tack loop 0.589
27 Crease patch pieces 0.236
28 Attach patch piece 0.333
29 Sew pleats 0.278
30 Attach yoke to back 0.475
31 Top stitch back yoke 0.365
32 Join shoulder 0.64
33 Top stitch shoulder 0.656
34 Attach collar 0.535
35 Close collar with size label 1.01
36 Sleeve attach 0.862
37 Top stitch armhole 0.678
38 Top stitch side seam 1.036
39 Attach & close cuff 0.696
40 Top stitch cuff 0.524
41 Hem bottom 0.947
Total SAM 22.322
8. Operation Breakdown and SMVs of a Basic Jeans
Operation breakdown of a 5 Pocket Basic Jeans is listed in this article. SMVs mentioned here against each
operation are just for your reference. SMVs may vary according to machine types, workstation layout and
equipment used. Some of operations are done by automatic machines, like auto pocket hemming (APH),
auto pocket attaching (APS) etc. Machines that are used for the operations have been mentioned in third
column (M/c type) of the following table.
This Operation Breakdown has been taken from a Jeans manufacturing company in Vietnam.
Table 1: Operation Breakdown Chart
Sl. no. Operations M/C Type SMV
Back
1 pocket hemming APH 0.07
2 pocket o/l 3T O/L 0.3
3 pocket creasing ADPC 0.4
4 pocket attaching APS 0.74
5 second stitch @ back
pocket
SNLS 0.65
6 back yoke attach FOA 0.41
7 back rise join FOA 0.24
8 size label attach SNLS 0.2
Front Section
9 coin pocket hemming APH 0.015
10 coin pocket attach @
jet piece (right)
SNLS 0.2
11 pocket bag attach
with jet piece
5T F/L 0.42
12 o/l @ pocket bag 3T O/L 0.68
13 top stitch @ pocket
bag
SNLS 0.4
14 o/l @ zipper fly 4T O/L 0.3
15 o/l front panels @
crotch
3T O/L 0.26
16 zipper attach @ left
fly
DNLS 0.32
17 left fly attach @ front
panel (inseam & top
stitch)
SNLS 0.34
18 J-stitch @ left fly APJ 0.58
19 front pocket mouth
hemming
DNFPH 0.3
20 Pocket bag stitch to
front panel @side &
top (wt w/c label@lt.)
SNLS 0.46
21 right fly attach with
zipper & crotch join
SNLS 0.25
Assembly
22 loop preparation 3T F/L 0.15
23 main label attach @
waist band, & w/b
joining in chain
SNLS 0.3
24 top stitch @ inseam FOA 0.55
25 side seam join (attach
front & back panels)
5T O/L 0.65
26 top stitch @ side
seam
SNLS 0.38
27 waist band stitch WBAM 0.38
28 waist band corners
finish
SNLS 0.72
29 loop attach ABLA 0.65
30 bottom hemming BHM 0.33
Total 11.65
9. Full form of sewing machine name
APH - Automatic pocket hemming machine
ADPc - Automatic pocket creasing machine
APc - Auto pocket stitching machine
SNLS - Single needle lock stitch
FOA - Feed of the arm
3TO/L - 3 thread overlock (overedge)
5TF/L - 5 thread flat lock (cover stitch)
4TO/L - 4 thread over lock
5TO/L - 5 thread over lock
DNLS - Double needle lock stitch
3TF/L - 3 thread flat lock (cover stitch)
APJ - Auto J-stitch making
DNFPH - Double needle front pocket hemming
WBAM - Waistband attach machine
ABLA - Auto loop attach
BHM - Bottom hemming machine
(Note: Some of the machine names are short form of machine used for the specific operation
used by a company. Other companies may name it different way)
Denim is known as all-time fashion for all age group and for both sex. The demand of
denim pants are always there. To supply enough Jeans to the sourcing countries
entrepreneurs are setting plants in low labor cost countries. Bangladesh is one such example.
To reduce the manufacturing cost high end technology are used in denim plants with basic
machines. Specialized machines and semi-automatic machines are used in sewing, i.e. patch
pocket pattern making, surging panels and automatic patch pocket attaching. A plant of 500
machines can be set with following machine mix.
About the Contributor of this Denim topic: Md. Mostafiz Uddin is in the Apparel
Trade since 1999. Currently he is holding the post of Managing Director at Denim Expert
Ltd, a Denim Manufacturing Company.
10.
11. Operation Breakdown and SMVs of a Basic Polo tee-shirt
We have done this experiment in SM Knitwear Ltd. Bangladesh.
We attempted this study for proper utilization of man and machine. We
made a little bit change of existing line balancing and process layout for
number of operations that was done by man power. In this experiment
we used auto machines in some operations instead of man power and
also find out the performed SMV after the modification of operations.
Process layout line balancing and SMV of Polo- shirt
Sl. No. Operations Machines Stitch type Man power
Performed
SMV
Helper Operator
1 Placket position mark Helper − 1 0.374
2 Placket fusing Iron man − 1 0.396
3 Body scissoring Helper − 1 0.33
4 +Both placket joint on front part LS 1N Lock Stitch 2 0.946
5 Placket nose tack LS 1N Lock Stitch 1 0.462
6 Placket raw edge cut Helper − 1 0.469
7 Lower placket close LS 1N Lock Stitch 1 0.418
8 Upper placket close LS 1N Lock Stitch 1 0.418
9 Placket security tack LS 1N Lock Stitch 1 0.396
10 Placket box LS 1N Lock Stitch 1 0.484
11 Body match Helper − 1 0.33
12 Shoulder joint with piping OL
Over edge
Stitch 1 0.44
13 Shoulder top stitch FL
Chain / Flatbed
Stitch 1 0.44
14 Collar mark Helper − 1 0.396
15 Collar over lock OL
Over edge
Stitch 1 0.806
16 Collar joint OL
Over edge
Stitch 2 0.418
17 Neck piping FL
Chain / Flatbed
Stitch 1 0.44
12. 18 Neck top stitch LS 1N Lock Stitch 1 0.44
19 Main label joint LS 1N Lock Stitch 1 0.396
20
Sleeve match and shoulder piping
cut Helper − 1 0.33
21 Sleeve joint OL
Over edge
Stitch 2 0.682
22 Bottom hem FL
Chain / Flatbed
Stitch 1 0.352
23 Care label joint LS 1N Lock Stitch 1 0.374
24 Placket servicing OL
Over edge
Stitch 1 0.352
25 Side seam OL
Over edge
Stitch 2 0.77
26 Side slit tape measure and cut Helper − 1 0.33
27 Side slit tape attach LS 1N Lock Stitch 2 0.66
28 Side slit tape top stitch LS 1N Lock Stitch 2 0.704
29 Slit security tack LS 1N Lock Stitch 1 0.286
30 Button attach and hole mark Helper − 1 0.308
31 Button hole BH 1N Lock Stitch 1 0.297
32 Button attach BS 1N Lock Stitch 1 0.308
8 30
Total man= 38
Total SMV
≈14.552