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Case Study CS0001:
IMPROVEMENT OF PRODUCTIVITY THROUGH SMED METHOD
Preface:
The Porvic-II separator plant was unable to meet the quantity requirements for separators at the assembly stage. As a result, separators had to be bought from outside vendors. This amounted to cost escalations as well as inconsistency. So the management decided to take a closer look at the productivity of P-II plant. The principle of Single Minute Exchange of Dies (SMED) was utilised for achieving the desired productivity improvement .
Objectives:
- Reduction of production loss due to down time.
- Reduction of energy loss.
- Reduction of purchase of bought out seperators.
- Supplying the required quantity of separators to assembly line (customer
to P - II) as per plan and just in time.
Data collection on plant down-time:
| Month |
Total production hours |
Mechanical break-down hours |
Electrical break-down hours |
Number of Die changes |
Die change hours |
Total down time hours |
| July |
636 |
0 |
0 |
20 |
40 |
40 |
| August |
480
| 1 |
1 |
13 |
26 |
28 |
| September |
268 |
0 |
1 |
7 |
14 |
15 |
| October |
360 |
1 |
0 |
9 |
18 |
19 |
| November |
312 |
8 |
4 |
18 |
36 |
48 |
| December |
744 |
0 |
0 |
39 |
78 |
78 |
| Total |
2800 |
10 |
6 |
106 |
212 |
228 |
Data summary:
| Cause of down time |
Down-time hours |
% of total down-time |
| Mechanical break-down |
10 |
4.38 |
| Electrical break-down |
6 |
2.62 |
| Die change |
212 |
93.00 |
| Total |
228 |
100 |
Maximum down-time (93%) occured due to die change only. So it was decided
to concentrate on reduction of down-time due to die change. Further data
collection was made on the details of various elements of die change process.
Pareto analysis
table for die change jobs:
| Work Element |
Time taken (minutes) |
Cumulative time |
% of total |
Cumulative % |
| Die change |
75 |
75 |
62.50 |
62.50 |
| Die adjustment & sample test |
18 |
93 |
15.00 |
77.50 |
| Belt speed adjustment & temperature adjustment |
16 |
109 |
13.33 |
90.83 |
| Width & height cutting adjustment |
11 |
120 |
9.17 |
100 |
| Total |
120 |
|
100 |
|
It was evident that die change and die adjustment together account for
77.5% of the total set up time.
A brain storming session followed.
The participants came up with four alternatives for die fixture design.
| Sl. No |
Alternative Methods |
Advantage / Disadvantage |
Selected / Rejected |
| 1 |
One fixture accomodating 1 die |
Existing method |
Rejected |
| 2 |
One fixture accomodating 2 dies |
Better than option - 1 |
Rejected |
| 3 |
One fixture accomodating 3 dies |
Better than option - 2 |
|
| 4 |
One fixture accomodating 4 or more dies |
Can not accomodate more than three dies in one fixture due to space
problem. |
Rejected |
Corrective actions
taken:
1. Die fitting fixture was modified from single die fixture to tripple
die fixture.
2. Bearing block was modified.
3. Bearing block and pulley fitted on each die.
4. Measuring scale setting introduced at cutting unit.
Comparison of
results:
|
Actual figures after improvement |
|
|
Calculation as per previous condition |
|
|
| Month |
Number of die changes |
Down-time* (hours) |
Production in numbers |
Down-time (hours) |
Production in numbers |
Balance |
| August |
20 |
10 |
6,66,000 |
40 |
5,36,000 |
1,30,000 |
| September |
26 |
13 |
8,58,000 |
52 |
6,96,800 |
1,61,200
|
| October |
16
|
8
|
5,28,000
|
32
|
4,28,000
|
1,00,000
|
| November |
24
|
12
|
7,92,000
|
48
|
6,43,200
|
1,48,800
|
| December |
25
|
12.5
|
8,25,000
|
50
|
6,70,000
|
1,55,000
|
| January |
30
|
15
|
9,90,000
|
60
|
8,04,000
|
1,86000
|
| Total |
141
|
70.5
|
46,59,000
|
282
|
37,78,000
|
8,81,000
|
| Average / month |
24
|
12
|
7,76,500
|
48
|
6,29,666
|
1,46,833
|
* Please note that the actual downtime due
to die change has come down from 2 hrs to only 30 minutes per die change
after implementing the new method.
Tangible
benefits:
1. Additional production capacity generated per annum = 1.762 Million
Pieces.
( Average additional production capacity generated per
month = 1,46,833 Nos.
Average additional production capacity generated
per annum = 17,62,000 Nos. )
2. Energy savings / annum = 28,800 kW
( Power consumption per day = 1600 kW
Reduction in downtime per die change
= 1.5 hrs
Power saved per die change = 100 kW
Average number of die changes/annum
= 24 x 12 = 288
Energy savings / annum = 288 x 100 =
28,800 kW )
Intangible benefits:
1. Development of new ideas.
2. Better team work.
3. Better customer satisfaction.
4. Improvement in morale.
5. Another step forward for Just-in-Time system.
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