ME 682 Project

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Uma Dundigalla (00875528)

ME 682

Concurrent Engineering

Project Report On

Lean Case Study

Submitted By

Uma Rani Dundigalla

UIN: 00875528

Part2:

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Customer Demand:

230,400 sets per year

A set is of one top and one bottom,

Out of 230,400 sets,60% in blue and 40% in green

About Factory:

2 assembly shifts@480 mins per shift

240 working days per year

Container quantity:20 per box for Tops ,30 per box for bottoms

As per customer demand factory should manufacture;

Number of sets/day= customer demand/working days

=230,400/240

=960 sets/day

Out of which 60% should be blue:

960*.60=576 sets of blue color

Remaining 40% should be green=384 sets

a)TAKT Time:

TAKT Time: The word derived from german word takzeit which translates to

cycle time. TAKT time can be defined as the maximum time per unit allowed

producing a product in order to demand.

TAKT time aims to match the pace of production with customer demand.

TAKT Time= Available time/Required production

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= (2*480)/960= 1 min/set

b) Pitch:

Pitch=TAKT Time* Quantity per box

Pitch Top= 1minute* 20 tops=20 minutes

Pitch Bottom = 1minute*30 Bottoms=30 minutes

c)Buffer Stock:

Buffer Stock: A supply of inputs held as a reserve to against short term shortage

and or to dampen excessive fluctuation in the prices of commodities and thusprotect local exporters from wild swing in world of commodity prices.Buffer stock

is based on the highest difference between actual number of parts shipped and the

average number.

Safety Stock:

Safety Stock: It is an inventory held as buffer against mismatch between forecasted

and actual consumption or demand between expected and actual delivery time and

unforeseen emergencies.it is also called as reseve inventory.

Safety stock per shift,

Blue set production per shift=576/2 =288 sets

Green set production per shift=384/2=192 sets

As one box contains 20 tops and 30 bottoms,

Safety Stock for

Blue tops=280

Blue bottoms=210

Green tops=280

Green bottoms=210

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d)Operator assignments for the combined paint and assembly line

PAINT and Assembly Station

For bottom part

TASK ID Description Most frequent time

B1 Side to base 26

B2 s/b to leg 24

B3 s/b/l to cap 10

B4 Add clip 10

B5 Inspect 8

B6 Pack 4

total 82 sec

To assemble bottom part it will take 82 secs

For top part

TASK ID Description Most frequent time

T1 Strut to arm 28

T2 s/a to base 18

T3 s/a/b to cap 14

T4 Add clip 14

T5 Inspect 8

T6 Pack 4

total 86 sec

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To assemble top part it will take 86 sec

To paint bottom and top parts it will take 13 sec

For combined Paint and Assemble Station it will take 181 secs

Number of operators needed= 181 sec/60 sec(TAKT time)

=3 operators

T6

B3 T3 B6

T5

B2 T2 B5

B1 T1 T4

B4

Operator 1 Operator 2 Operator 3

e)Machine Balnce for all three Presses:

Tool change over time=120 mins

Color change over time=15 mins

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Total cycle time for all tools=237 secs

Runtime/day(minutes)= (960*cycle time)/60

Machine Balnce Solution for Press 1(200T)

Press 1includes T08,T10 and T14

Sr No TOOL ID Part Process Time

(Sec)

Operator Time

(Sec)

Runtime/day

(min)

1 T08 Blue top

Base+Green

Top Base

34 8 544

2 T10 Blue Top

Cap+Green

Top Cap

23 8 368

3 T14 Blue Bottom

Cap+Green

Bottom Cap

23 8 368

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Calculations:

Time required for molding process per day=1685 min

Available time= 3shifts*8hrs*60 mins=1440

Available Productive time=0.90*14401296

From above calculations we are off by 1685-1296=389 minutes

Machine Load Chart for Press 1(200T)

Press#1 min

T08 544

T/C 120

T10 368

T/C 120

T14 368

T/C 120

C/C 60

Let x be the reduction time in c/o tool

y be the reduction time in c/o color

3x+3y=389 mins

3(x+y)=389 mins

x+y=128 mins

say x=115 and y=13

so new c/o tool =120-115=5 mins

newclo color=15-13=2mins

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which is impossible.

If there is 100% available productive time then

Off time =1685-1440=245mins

3x+3y=245

x+y=81

say x=79 and y=2

then new c/o tool =120-79=41mins

new c/o color=15-2=13 mins.

Machine Balnce Solution for Press2(300T)

Press 2 includesT07,T11 and T13.

Sr no TOOL ID Part Process

Time

(sec)

Operation

time

(sec)

Runtime/day

(min)

1 T07

Blue top

Arm+Green top

Arm30 8 480

2 T11

Blue bottom

Side+Green

bottom Side24 8 384

3 T13

Blue bottom

Leg+Greenbottom Leg

25 8 400

Time required for Molding process per day=1669 minutes

Available time=3shifts*8hrs*60 min=1440 minutes

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Actual productive time=0.9*1440=1296 minutes

From above calculations we are off by 1669-1296=373 mins

Machine Load Chart for Press2:

Press#2 min

T07 480

T/C 120

T11 384T/C 120

T13 400

T/C 120

C/C 45

Let x be the reduction timein c/o tool


3x+3y=378 mins

x+y=126mins

say x=113 and y=13

So new c/o tool =120-113=7 mins

new c/o color=15-13=2mins

which is impossible

is there is 100 % available productive time the

Off time=1669-1440=229 mins

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3x+3y=225

x+y=75

Say x=73 and y=2

Then new c/o tool =120-73=47 mins

new c/o color=15-2=13 mins

Machine Balnce Solution for Press 3(350T)

Press 3 includes T09 and T12

Sr no TOOL ID Part Process

time

(sec)

Opertion

time

(sec)

Runtime/day

(min)

1 T09

Blue top

Strut+Green

top Strut38 8 608

2 T12

Blue

bottom

Base+Green

bottom

Base

40 8 640

Time required forMolding process per day=1518 mins

Available time=3shifts*8hrs*60 mins=1440 min

Available Productive time=0.9*1440=1296 min

From above calculations we are off by 1518-1296=222 mins

Machine Load Chart for Press3(350T)

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Press#3 min

T09 608

T/C 120

T12 640

T/C 120C/C 30

Let x be the reduction time in c/o tool


2x+2y=222

x+y=111

Say x=98min and y=13 min

Then new c/o tool =120-98=22 min

new c/o color=15-13=2 min

which is impossible.

If there is 100% available productive time then

Off time=1518-1440=78 min

2x+2y=78

x+y=39

Say x=37 and y=2

Then,new c/o tool=120-37=83 min

New c/o color=13 min

f)Kanban System:

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A Kanban system is a means to achieve just in time production. It works on the

basis that each process on a production time pulls just the number and type of

components the process requires at just the right time. The mechanism used is akanbancard .this is usually a physical card but other devices can be used two types

of such cards are usually used.

Withdrawal kanban :specifies the kind and quantity of product which a

manufacturing process should withdraw form a preceding process.

Customer demand=230,400 sets/year

Number of working hours=240/year

Required sets per day=230400/240=960 sets

Top assembly should be packed in 20 per box

Bottom assembly should be packed in 30 per box

Out of 960 60% blue and 40% green

Blue top=960*60%=576 BT/day

=576/2shifts=288BT/shift

No of Cards=288/20=14.415 cards

Blue Bottom=960*60%=576Bb/day

=288Bb/shift

No of Cards=288/30=9.610 cards

Green top=960*40%=384Gt/day

=192Gt/shift

No of Cards=192/20=9.610Cards

Green bottom=960*40%=384Gb/day

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=192Gb/shift

No of Cards=192/30=6.47 Cards

Blue

Top

BlueBottom

Green Top

GreenBottom

PickUp

Cum'P.U.

PickUp

Cum'P.U.

PickUp

Cum'P.U.

PickUp

Cum'P.U.

TotalP.U.'s

6:00 1 20 1 30 2

6:20 1 20 1 30 2

6:40 1 40 1 60 2

7:00 1 60 1 90 2

7:20 1 40 1 60 2

7:40 1 80 1 60 2

8:00 1 100 1 120 2

8:20 1 80 1 90 2

8:40 1 100 1 120 2

9:00 1 120 1 120 2

9:20 1 140 1 150 2

9:40 1 140 1 150 2

10:00 1 160 1 180 2

10:20 1 160 1 180 210:40 1 180 1 180 2

11:00 1 200 1 210 2

11:20 1 220 1 240 2

11:40 1 200 1 210 2

12:00 1 240 1

12:20 1 260 1 270 2

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12:40 1 280 1 300 2

1:00 1 300 1

1:20 01:40 0

2:00 0TotalBox's

15 10 10

7

g)Heijunka Box

6:

00

6:

20

6:

40

7:

00

7:

20

7:

40

8:

00

8:

20

8:

40

9:

00

9:

20

9:

40

10:

00

10:

20

10:

40

11:

00

11:

20

11:

40

12:

00

12:

20

12:

40

1:

00

1:

20

1:

40

2

00

BT

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

BB

1 1 1 1 1 1 1 1 1 1 1 1

GT

1 1 1 1 1 1 1 1

GB

1 1 1 1 1

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1.Heijunka Box-FG Storage(WKB).

Withdrawal kanban card between heijunka box and Fg storage contains following

information

Part number

Part Name Blue Bottom

Name of preceding process Storage

Name of subsequent Process -

Box capacity 30

Number of boxes 10

2.FG Storage-Paint and Assembly (PKB)

Production Kanban card between FG Storage and Paint &Assembly shop contains

following information

Part Number

Part Name Blue bottom

Name of Process Paint & Assembly

Part Type Side.Base,Leg,Cap.Assembly

3.Paint& Assembly Molding Storage (WKB)

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Withdrawal kanban card between paint and Assembly-Molding Storage contains

fllowing information

Part number

Part name Blue bottom

Name of Preceding Process Molding Storage

Name of Subsequent Process Paint and Assembly

Box capacity 30

Number of Boxes 10

4.Molding Storage-Molding (PKB)

Production kanban card between molding storage molding contains following

information

Part number


Name of Process Molding

Part types Side,base,leg,cap

5.Molding-Raw material Storage(WKB)

Withdrawal kanban card between Molding-Raw material Storage contains

following information

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Part number


Name Of preceding process Storage

Name of Subsequent Process Molding

Box capacity 30

Number of Boxes 10

This cycle must be completed by the man within 20 minutes

This goes on till 2.00 PM where the shift completes.

Documents

ME 682 Project