Implementing Cellular ManufacturingAt Pakistan Spring & Engineering Co. (Ltd.)

• To shorten lead times• To reduce inventory• To improve quality• To simplify Production scheduling• To reduce setup time

Why it is done?

Producing according to Takt Time (Line Balancing) Planning of layout must be feasible in order to cater

the cells made Pull system has to be integrated to the parts that are

to be arranged in a cell (Kanban) Individual Changeover times of machines must be

reduced to a minimum in order to benefit from cellular manufacturing

Prerequisites

Step 1

Data Collection

• Body C CD 70 cc• Seat Spring• Mouth Collar• Plate Baffle• Main Plate for Honda CG 125• Suzuki pickup steering spoke

Parts

Our Parts

Body C of CD 70 cc

Our Parts

Seat Spring of Honda CD 70 cc

Our Parts

Mouth Collar of Honda CD 70 cc

Our Parts

Plate Baffle of Honda CD 70 cc

Our Parts

Main Plate of Honda CG 125

Our Parts

Suzuki pickup steering spoke

Operations

Machine names with processes

Blanking on shearing press

Blanking on power press

1st Draw on Hydraulic Press

2nd Draw on Hydraulic Press

Cutting on Lathe

Facing on Lathe

Trimming on Power Press

Bending on Power Press

Punching on Pneumatic Press

Piercing on Power Press

Step 2

Sortation of process routings

A. Body C CD 70 cc 2-3-4-6-7 2000

B. Seat Spring 2-3-6-7 2500C. Mouth Collar 5-8-9 5000D. Plate Baffle 2-3-4-7 3000E. Main Plate for Honda CG 125 1-9-8 2500F. Suzuki pickup steering spoke 1-9-10-8 2500

Parts

Part Code Part Name Routing

Monthly Producti

on

OperationsOperation

Code Machine names with processes

1 Blanking on shearing press2 Blanking on power press

31st Draw on Hydraulic Press

4 2nd Draw on Hydraulic Press5 Cutting on Lathe6 Facing on Lathe7 Trimming on Power Press8 Bending on Power Press9 Punching on Pneumatic Press

10 Piercing on Power Press

Step 3

Process Flow Analysis (PFA) Chart/ Part-Machine incident

Matrix

Operations PartsA B C D E F

1 I I2 I I I 3 I I I 4 I I 5 I 6 I I 7 I I I I8 I I I9 I I I

10

Part machine Incident Matrix

Step 4

Cluster AnalysisPart I – Rank Order Clustering

OperationsParts

Decimal Equivalent Rank32 16 8 4 2 1

A B C D E F1 I I 3 9

2 I I I 52 1

3 I I I 52 2

4 I I 36 5

5 I 8 8

6 I I 48 4

7 I I I I 52 3

8 I I I 11 6

9 I I I 11 7

10 1 10

1st Iteration

1st Iteration

OperationsParts

32 16 8 4 2 1

A B C D E F2 I I I3 I I I7 I I I6 I I4 I I8 I I I9 I I I5 I1 I I

10 I

2nd IterationOperations Parts

A B C D E F2 I I I 512

3 I I I 256

7 I I I 128

6 I I 64

4 I I 32

8 I I I 16

9 I I I 8

5 I 4

1 I I 2

10 I 1

DecimalEquivalent 992 960 28 928 26 27

Rank 1 2 4 3 6 5

2nd Iteration

OperationsParts

Decimal Equivalent Rank32 16 8 4 2 1

A B D C F E

2 I I I 56 1

3 I I I 56 2

7 I I I 56 3

6 I I 48 4

4 I I 40 5

8 I I I 7 6

9 I I I 7 7

5 I 4 8

1 I I 3 9

10 I 2 10

Step 4

Cluster AnalysisHollier Method 2

From - To

To OperationCode Machine names with processes From

0 1 Blanking on shearing press 2500+2500

0 2 Blanking on power press 2000+2500+3000

2000+2500+3000 3 1st Draw on Hydraulic Press 2000+2500+3000

2000+3000 4 2nd Draw on Hydraulic Press 2000+3000

0 5 Cutting on Lathe 5000

2000+2500 6 Facing on Lathe 2000+2500

2000+3000+2500 7 Trimming on Power Press 0

5000+2500+2500 8 Bending on Power Press 5000

5000+2500+2500 9 Punching on Pneumatic Press 2500+2500

2500 10 Piercing on Power Press 2500

From - ToCluster 1

From

To

2 3 4 6 7 From sums From/To Ratio

2 0 7500 0 0 0 7500 ∞

3 0 0 5000 2500 0 7500 1

4 0 0 0 2000 3000 5000 1

6 0 0 0 0 4500 4500 1

7 0 0 0 0 0 0

To Sums 0 7500 5000 5000 7500 24500

Network Diagram

3 42 6 77500 7500

7500

2500

5000 2000

3000

4500

Performance Measures

Percentage in sequence moves = 19000/24500*100 = 77.5%

Percentage By-Passing Moves = 5500/24500*100 = 22.5 %

Percentage Back Tracking Moves = 0/24500*100 = 0 %

From-ToCluster 2

From

 

    To    

1 5 8 9 10 From sums

From/To Ratio

1 0 0 0 5000 0 7500 ∞

5 0 0 5000 0 0 7500 ∞

8 0 0 0 5000 0 5000 0.5

9 0 0 2500 0 2500 4500 0.5

10 0 0 2500 0 0 0 1

To Sums 0 0 10000 10000 2500 22500  

Network Diagram

5 101 8 95000 0 5000

2500

0 2500

5000

5000

5000

5000

5000

2500

Performance Measures

Percentage in sequence moves = 7500/22500*100 = 33.33%

Percentage By-Passing Moves = 10000/22500*100= 44.44 %

Percentage Back Tracking Moves = 5000/22500*100 = 22.22 %

Conclusions

2 cells are made comprising of 5 machines

The cells are type II M (Group machine cell with manual handling)

For 1st cluster U shaped layout is suggested (As there are in sequence moves)

For 2nd cluster rectangular layout is suggested (As there are back track moves)

There is a drastic reduction in the “transportation” and “motion” waste