Line balancing

Line balancing

© SOFT Student Handouts,By, Sunil Talekar, Faculty, SOFT-

Pune

What is line in apparel manufacturing?

Line: an assembly line composed of several work stations, at which specific operations are performed. To work effectively, with no work pile-ups between stations, the line must be balanced,e.g. work must get through each workstation in roughly the same amount of time.

What is Line Planning? Line planning is scheduling and allocating of orders to production lines according to product setting (product is being made in the line) and due dates of production completion. A line plan defines when a style is going to be loaded to the line, how many pieces to be expected (target) from the line and when order to be completed. For example, please refer to the following Table-1, where a simple line planning has been shown in spread sheet.

During booking orders or allocating orders to the production line, planners must check what is running on the line and how many days it will take to complete the Running style.

Benefit of Line planning: It helps production manager as well as line supervisor with information such as what is the daily production target for line. They set their line (machines and manpower) accordingly. Line plan also provides information such as how many days style would run, what is the next style going to be loaded?

Line plan

Line 1 Line 2 Total

DateDaily Prod.

Cumm Prod.

Daily Prod.

Cumm Prod.

Daily Prod.

1-Decloading #2341A, Qty -3000 pieces 300 1200 300

2-Dec 200 200 300 1500 5003-Dec 250 450 300 1800 5504-Dec 400 850 200 2000 600

5-Dec 400 1250loading #Polo ,

Qty -1500 pieces 4006-Dec 400 1650 0 0 4007-Dec 400 2050 100 100 5008-Dec 400 2450 300 400 7009-Dec 400 2850 350 750 750

10-Dec 150 3000 350 1100 500

11-Decloading #432K, Qty -5500 pieces 400 1500 400

12-Dec 100 100loading #YK45, Qty -4500 pieces 100

13-Dec 250 350 200 200 450

14-Dec 500 850 250 450 750

15-Dec 500 1350 400 850 900

16-Dec 500 1850 400 1250 900

17-Dec 500 2350 400 1650 900

18-Dec 500 2850 400 2050 900

19-Dec 500 3350 400 2450 900

20-Dec 500 3850 400 2850 900

21-Dec 500 4350 400 3250 900

22-Dec 500 4850 400 3650 900

23-Dec 150 5000 400 4050 550

Daily Prod. – Daily production or line outputCumm Prod. – Cumulative production of the style till date

LINE BALANCING

LINE BALANCING (Process Organization) The Line Balancing is “ to design a smooth production flow by allotting processes to workers so as to allow each worker to complete the allotted

workload within an even time ”

LINE BALANCING (Process Organization) It is a system where you meet the production expectations and you can find the same amount of work in process in every operation at any point in the day.

WHY LINE BALANCING…@ the main job in line balancing is to eliminate or reduce wip (work in process) at bottleneck operations.

@ keeps inventory costs low, resulting in higher net income

@ allows operator to work all day long giving an opportunity to earn more money and increases his/her work effi ciency

@ keeps the prices low which turns into repeat sales

@ means better production planning

Line balancing in apparel manufacturing

there are 3 rules for balancing

(1) have at least ½ hour of wip for each operation .

(2) Solve problems before they become any larger.

(3) Meet production goals by keeping every operator working at their maximum capacity .

LINE BALANCING TOOLS

Production sheetsDaily production report

The inventory levels by operation

Production boardsStop watch

Calculator


STEPS TO A BALANCED LINESTEP 1. CALCULATION OF THE LABOR REQUIREMENTS AND CAPACITY STUDY THE REQUIREMENT OF WORKER DEPENDS UPON THE PROBABLE EFFICIENCY OF THE LINE SELECTED AND PERCENTAGE OF TIME THEY WORK.

List down all operations with operator name as per operation sequenceCheck cycle time for

each operation for five consecutive cyclesWith average cycle

time calculate hourly capacity of the operatorsWith the help of the hourly capacity, calculate the labour requirement


STEP 2. OPERATIONAL BREAKDOWN AND SETTING THE TARGET

B.• With the capacity data set target

output per hour from one line.

C.• Target per hour = Total no of

operators X 60 /garment SAM

D.

• Current hourly operator production report is analyzed

STANDARD ALLOWED MINUTES OF EACH OPERATION

+A.


STEP 3: TARGET SETTING

With the above step 1 & 2 data set your target output per hour from one line.

Generally it is calculated using following formula (Target per hour= Total no of operators X 60 /garment SAM).

Check current hourly operator production report. Draw a straight line with target output data on the line graph.

* The time at which the longest time is required is called “Bottleneck Process”* The state of line organization should be evaluated as “Organization Efficiency” * Pitch Time provides average time allotted to each worker. * Using the pitch time and Bottleneck Process Time.

STEP 4. IDENTIFICATION OF BOTTLENECK AREAS

A B C D E F G H0

20

40

60

80

100

120

140

1601st Bottleneck

area

Loss in balance

Loss in balance

2nd Bottleneck area

Loss in balance

Bottleneck process

Name of worker (In order of processes)

Work

Allotm

ent

Tim

e

Hanes

See picture of knitted trunk short, and develop operation breakdown and confirm possible bottleneck

STEP4. ELIMINATION OF BOTTLENECKS FROM THE LINE

Club operations where possible. Give the operator another operation with less work

content considering machine type and sewing thread colors. Shuffle operators. Operations that have low

work content use low performer while work content is higher use high performers.Add more operators at bottleneck operations.

Also compare the cost-benefits of putting additional machine into the line.

Improve workstation layout and improve methods

Do extra work at bottleneck operations.

Reduce cycle time using work aids and attachments

Methods of eliminating bottlenecks from the line


FROM IMBALANCED LINE..

To Balanced line

All in all…

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

Product: Full Sleeve Men’s Formal Shirt. Brand: Arrow

From given table draw a line diagram as well balance the line.

Education

Line balancing