1
Plant LayoutPlant Layout
A Systematic Layout Planning A Systematic Layout Planning (SLP) Approach(SLP) Approach
Mohamed Iqbal PallipurathMohamed Iqbal Pallipurath
2
THE NEED FOR THE NEED FOR GOOD FACILITIES PLANNINGGOOD FACILITIES PLANNING
1.1. Plant facilities influence operating costs and profits.Plant facilities influence operating costs and profits.2.2. Planning allows facilities and its operations (OSHA, Planning allows facilities and its operations (OSHA,
ISO 14001, etc.) to comply with laws and/or ISO 14001, etc.) to comply with laws and/or regulations.regulations.
3.3. Facilities are fixed investments involving high capital-Facilities are fixed investments involving high capital-cost expenditures.cost expenditures.
4.4. Facilities are inflexible and long term commitments.Facilities are inflexible and long term commitments.5.5. The planning, design and construction of facilities The planning, design and construction of facilities
require long lead times.require long lead times.6.6. Good planning helps to avoid disruptions in Good planning helps to avoid disruptions in
production and shipping or delivery.production and shipping or delivery.
3
THE NEED FOR THE NEED FOR GOOD FACILITIES PLANNINGGOOD FACILITIES PLANNING
7.7. The quality of facilities influences the attitudes of The quality of facilities influences the attitudes of and the ability to attract suitable employees.and the ability to attract suitable employees.
8.8. Industrial facilities must be planned to meet Industrial facilities must be planned to meet anticipated future requirements yet compete anticipated future requirements yet compete profitably today.profitably today.
9.9. Facilities need to be planned for an appropriate Facilities need to be planned for an appropriate degree of flexibility, expandability, versatility…degree of flexibility, expandability, versatility…
10.10. Good plans help management to take advantage Good plans help management to take advantage of business opportunities that arise.of business opportunities that arise.
11.11. Good planning is an aid to obtain approval and Good planning is an aid to obtain approval and financing monies.financing monies.
12.12. Good planning reduces the high materials handling Good planning reduces the high materials handling $ resulting from “ad hoc” expansion of plant $ resulting from “ad hoc” expansion of plant facilities.facilities.
ECONOMIC IMPACT OF FACILITIES PLANNINGECONOMIC IMPACT OF FACILITIES PLANNING
Time
Eco
nom
ic I
nves
tmen
t/C
onse
quen
ce (
$)
Plan20:1
Design2:1
Build & Install1:10
Resources invested to provide the facilities
Consequence on operations of facilities
5
DEFINING PERFORMANCE DEFINING PERFORMANCE OBJECTIVESOBJECTIVES
1.1.
2.2.
3.3.
6
DEFINING PERFORMANCE DEFINING PERFORMANCE OBJECTIVESOBJECTIVES
4.4.
5.5.
6.6.
7
TYPES OF MANUFACTURING TYPES OF MANUFACTURING LAYOUT CONFIGURATIONSLAYOUT CONFIGURATIONS
I.I. Product Line LayoutProduct Line Layout
Product
A
B
C
8
CHARACTERISTICSCHARACTERISTICS
High volume productionHigh volume production Special purpose machines and Special purpose machines and
material handling equipmentmaterial handling equipment Throughput rates--highThroughput rates--high Work-in-process--lowWork-in-process--low Setup/Run time ratio--lowSetup/Run time ratio--low
System is very inflexibleSystem is very inflexible Control is relatively simpleControl is relatively simple
TYPES OF MANUFACTURING LAYOUT CONFIGURATIONSTYPES OF MANUFACTURING LAYOUT CONFIGURATIONS
GOAL: GAIN the advantages and efficiency of high volume production in a LOW/MEDIUM VOLUME (FLEXIBLE) ENVIRONMENT.
II. Flow Line Workcell
T T T
M M T M
D D M D
SG CG CG D
SG
T = turningD = drillingM = millingCG = center grindingSG = surface grinding
10
GT-FLOW LINE WORKCELL GT-FLOW LINE WORKCELL CHARACTERISTICSCHARACTERISTICS
Buffer1
Buffer2
Bufferm
Workstation1
Workstation1
Workstationm
11
GT-FLOW LINE WORKCELL GT-FLOW LINE WORKCELL CHARACTERISTICSCHARACTERISTICS
1.1. Processes GT-based families of parts with frequent Processes GT-based families of parts with frequent job change-over and small to medium batch sizesjob change-over and small to medium batch sizes
2.2. Piece by piece (continuous flow) Piece by piece (continuous flow) processing/movementprocessing/movement
3.3. No backtracking in sequence flow, but machine No backtracking in sequence flow, but machine skipping does occurskipping does occur
4.4. Accommodates flexible-type automation: CNC Accommodates flexible-type automation: CNC machines, robots for part handlingmachines, robots for part handling
5.5. Finite buffers (resulting in machine blocking and Finite buffers (resulting in machine blocking and starvationstarvation
TYPES OF MANUFACTURING LAYOUT CONFIGURATIONSTYPES OF MANUFACTURING LAYOUT CONFIGURATIONS
III. Cellular Manufacturing(GT Workcell)
13
CHARACTERISTICSCHARACTERISTICS
1.1. Dissimilar processes/machinesDissimilar processes/machines
2.2. Similar parts (families) run in small to Similar parts (families) run in small to medium batch sizesmedium batch sizes
3.3. Mini - job shopsMini - job shops
Process(Functional) LayoutProcess(Functional) Layout
S S S
S S S
T T T
T T T
T T T
G G G
G G G
M
M
M
B B
B B
GC GC
GC GC
HT
HTHT
Sawing Turning
Heat Treating
Grinding
Milling
BoringGear Cut
“Shaft”
15
CharacteristicsCharacteristicsof Process Layoutsof Process Layouts
Low Volume, High Variety Production with Random Low Volume, High Variety Production with Random Routing (Spaghetti-Like Flow)Routing (Spaghetti-Like Flow)
General Purpose Machines--General Purpose Machines-- Machine setups are frequent and longMachine setups are frequent and long Work-In-Process -- HighWork-In-Process -- High Throughput Rates tend to be LowThroughput Rates tend to be Low Material Handling -- HighMaterial Handling -- High Operator Utilization -- Low?Operator Utilization -- Low? Throughput Times (Lead Time) -- HighThroughput Times (Lead Time) -- High
System is Very Flexible, produces many different System is Very Flexible, produces many different types of parts: gears, shafts, pinions, housings, types of parts: gears, shafts, pinions, housings, clamps, etc.clamps, etc.
THE P-Q CURVETHE P-Q CURVE
P
Q
Product A
Product B
Product C
Etc.
(High)
(Low)
(Low) (High)(P) Variety
(Q)
Vol
ume
or Q
uant
ity
Part Volume/Variety Relationships with Part Volume/Variety Relationships with Manufacturing Systems ConfigurationsManufacturing Systems Configurations
ProductLine
G.T.FlowlineWorkcell
G.T.Manufacturing
Workcell
Functional(Job-Shop)
Part Variety
PartVolume
(High)
(Low)
(Low) (High)
18
MATERIAL FLOWMATERIAL FLOW
Importance of Material Flow
Properly Planned Material Flow
Effective Arrangement of Facilities
Efficient Operations
Profitability/Viability
19
Efficient Operations InvolveEfficient Operations Involve::
1.1. Good utilization of floor spaceGood utilization of floor space
2.2. Reduced materials handlingReduced materials handling
3.3. Appropriate equipment utilizationAppropriate equipment utilization
4.4. SafetySafety
5.5. Less congestionLess congestion
6.6. Less wasted time/effortsLess wasted time/efforts
7.7. FlexibilityFlexibility
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MATERIAL FLOWMATERIAL FLOW
KEY QUESTIONSKEY QUESTIONS
1.1. What is the most effective What is the most effective sequencesequence of moving of moving materials?materials?
Eliminate?Eliminate?Combine?Combine?Improve?Improve?Change Order?Change Order?
2.2. What is the What is the intensityintensity and direction? and direction?
Need to visualize the flowNeed to visualize the flow
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FLOW OF MATERIAL vs P-Q MIXFLOW OF MATERIAL vs P-Q MIX
I
II
III
IV
LAYOUT TYPE
I Product LineII Flow Line WorkcellIII G.T. WorkcellIV Functional
TYPE ITYPE I
Operation Process Chart showing intensity of material flow and the out-flow of chips and scrap. (Muther, SLP)
0-4
0-5
0-1
0-2
0-3
0-6
Casting Sheet Steel
Turn
Drill
Storage
4 Tons 10 Tons
Turnings0.7 Tons
Turnings0.3 Tons
Bolts Scrap2 Tons
Offal1 Ton
3.3 Tons
3 Tons
9 Tons
7 Tons
10.5 Tons
9 Tons
Blank
Form
Trim
Assemble/Inspect
TYPE IITYPE II
1
Operation Part or Product A B C D
Saw
Center
Turn
Heat Treat
Grind
Mill
2
3
4
5
1
2
3
4
5
1
2
4
3
5
1
2
3
4
*
Multi-Product Process Chart
*Shows problem flow to be resolved by design engineering and manufacturing engineering
TYPE IIITYPE III5 8 7 13 1 10 2 11 14 3 15 4 9 612
4
1
6
8
3
9
2
14
12
5
7
13
11
10
Part-Machine Matrix ofProduction Flow Analysis
PartsMachines
Exceptions
TYPE IVTYPE IV
1 2 3 5 6 7 8 9 10 TOTALS4
1
2
3
4
5
6
7
8
9
10
TOTALS
FROM-TO CHART
TO
FROM
Turn
Hob
Slot
Broach
Heat Treat
Drill
Inspect
Wash
Mill
Store
Tur
n
Hob
Slo
t
Bro
ach
Hea
t Tre
at
Dri
ll
Insp
ect
Was
h
Mil
l
Sto
re
3 3 6 1 5 1
7 5 1
1
3
31
1 5
57
1
1
9
xy
910
1212
8 576
22 12
10576262
20
414
752
2
684631223216026- - -
- -
- -
- -
-
-
-
-
- -
-
-
-
-
-
-
-
-
-
=
=
=
=
=
=
=
=
------
- - - -
-
-
-
-
-
-
-
-
------
-
-
-
-
-
- - - -
-
----
-
-
- -
-
-
--
-
-
Number of Parts
Number of Pieces
RANK THE FLOWSRANK THE FLOWS
KEYA:E:I:O:U:
Absolutely NecessaryEspecially ImportantImportantOrdinaryUnimportant
FL
OW
- O
F -
MA
TE
RIA
L I
NT
EN
SIT
Y
500
10
00
150
0
2000
2
500
30
00
350
0
4000
4
500
A
E
I
OU
Act
ivit
yP
air
(Rou
te)
Seq
.N
o.
8-13
1-3
3-4
8-15
3-12
11-1
5
10-1
3
3-7
7-15
1-14
4-12
4-9
4-15
1-7
2-3
11-1
5
3-5
1-4
1-12
2-8
11-9
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
27
NON-FLOW (CLOSENESS) NON-FLOW (CLOSENESS) RELATIONSHIPSRELATIONSHIPS
Flow based on routings is not the sole Flow based on routings is not the sole basis for layout arrangements.basis for layout arrangements.
Adapted from Muther
28
NON-FLOW (CLOSENESS) NON-FLOW (CLOSENESS) RELATIONSHIPSRELATIONSHIPS
Other FactorsOther Factors Supporting ServicesSupporting Services
Tool Room (not routed)Tool Room (not routed) Rest AreasRest Areas Central Coolant TanksCentral Coolant Tanks Shop Superintendent’s OfficeShop Superintendent’s Office
Adapted from Muther
29
NON-FLOW (CLOSENESS) NON-FLOW (CLOSENESS) RELATIONSHIPSRELATIONSHIPS
Other FactorsOther Factors Separation of AreasSeparation of Areas
Welding away from assemblyWelding away from assembly
Outside Doors / Separate / N/COutside Doors / Separate / N/C
DirtyDangerous Separate
DelicateHigh Pop
Adapted from Muther
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NON-FLOW (CLOSENESS) NON-FLOW (CLOSENESS) RELATIONSHIPSRELATIONSHIPS
In some cases, flow is simply not In some cases, flow is simply not importantimportant
No Significant FlowNo Significant Flow Service, Repair, Tool RoomService, Repair, Tool Room Jewelry (one load per week)Jewelry (one load per week)
Adapted from Muther
RELATIONSHIP CHARTRELATIONSHIP CHARTI
1 U
U
U
U
U
A
2 E
2 I
2 O
3 I
4
D
2 U
U
U
U
I
2 O
2 U
U
O
4
I
2 I
2 U
U
O
2 O
2 O
2 O
3 O
4
U
E
2 U
I
2 O
2 A
2 O
3 O
4
U
U
I
2 O
2 U
I
3 U
U
I
2 U
U
E
5 X
6
E
2 I
2 E
2 O
3 I
4
U
U
U
U
U
U
UO
3 U
O
4
Adapted from Muther
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Punch Press
AuxiliaryPunch Press
Drilling
Grinding
GeneralFabrication
Wet Tumble
SpecialProduction
Raw MaterialStorage
In-ProcessStorage
Assembly
Shop Toilet
Shop Office andTool Room
1
2
3
2
3
4
5
6
7
8
9
10
11
12
13
14
15
1
This block shows relation between “1” and “3”
Importance of Relationship (top)
Reasons in Code (bottom)
32
RELATIONSHIP CHART CodesRELATIONSHIP CHART Codes
Code
A
E
I
O
U
X
CLOSENESS
Absolutely Necessary
Especially Important
Important
Ordinary Closeness OK
Unimportant
Undesirable
4
3
2
1
0
-1
“Closeness”Rating
Value
RELATIONSHIP CHARTRELATIONSHIP CHART
Adapted from Muther
Value
1
2
3
4
5
6
7
8
9
Equip. used by same persons
Movement of material
Movement of personnel
Supervision and/or support
Require same utilities
Noise and dirt
REASON
Reasons behind the “Closeness”
Value
RELATIONSHIP DIAGRAMSRELATIONSHIP DIAGRAMS
Vowel Letter
A
No. Value
4
No. of Lines Closeness Rating
Absolutely Necessary
Color Code
Red**
E
I
O
U
X
XX
3
2
1
0
-1
-2, -3, -4, ?
Especially Important
Important
Ordinary
Unimportant
Not Desirable
Extremely Undesirable
Orange Yellow**
Green**
Blue**
Uncolored**
Brown**
Black
Conventions for diagramming activity relationships
35
PROCEDURE/EXERCISEPROCEDURE/EXERCISE
E
U
U
I
E
U
O
U
I
I
U
X
I
X
X
U
A
IO
U
A
Parts Storage
Ship/Receiving
Welding
Testing
Machining
Assembly
Paint
Figure 1: Relationship Chart
5,000
10,000
2,500
2,500
7,500
5,000
2,500
1
2
3
4
5
6
7
Dept. Desc.Sq. FeetDept. No.
36
PROCEDURE/EXERCISEPROCEDURE/EXERCISE
Figure 2: From-To Chart (in Loads per Weeks)
1
1
TOFROM
2
3
4
5
6
7
2 3 4 5 6 7
50
50
120
120
20
120
20
20
5080
40170
170
37
Determine Total Flow
1
1
TOFROM
2
3
4
5
6
7
2 3 4 5 6 7
50
120
20
120
20
140
5080
90170
170
1
38
Rank the Flows2
0
20
40
60
80
100
120
140
160
180
200
0 1 2 3 4 5 6 7 8 9 10 11
Tot
al F
low
1-6
2-3
4-6
2-7
4-7
2-5
3-5
1-2
3-6
3-7
5-7
39
Combine Flow & Non-Flow Relationships3
Activity Pairs
1-21-31-41-51-61-72-32-42-52-62-73-43-53-63-74-54-64-75-65-76-7
30023010220-20-2-2042104
100040401030210033000
Combined Total Points
40027050423-22-1-2075104
Non Flow: Flow1 to 1 Ratio
40
Rank the Combined Points4
0
1
2
3
4
5
6
7
8
9
10
0 1 2 3 4 5 6 7 8 9 10 11
Tot
al P
oint
s
1-6
4-6
2-3
4-7
1-2
2-5
6-7
2-7
1-5
2-6
3-5
Activity Pairs5-
6
12 3-6
3-4
3-7
41
Develop Combined Relationship Chart(Flow and Non-Flow)
5
I
O
A
E
I
O
I
XX
O
X
XXA
E
I
Parts Storage
Ship/Receiving
Welding
Testing
Machining
Assembly
Paint
5,000
10,000
2,500
2,500
7,500
5,000
2,500
1
2
3
4
5
6
7
42
Develop Relationship Diagram6
Place “A” Relationship Values on Grid
Add the “E” Relationship Values and Adjust Diagram to Minimize Distance X Flow Value
Place “A” Relationship Values on Grid
i
ii
iii
6. Relationship Diagram6. Relationship Diagram+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
4 6 1
7 2 3
5AEI
OUX
XX
7. 7. Measures of EffectivenessMeasures of EffectivenessMin Z = Min Z = LL DDijijijijjjii
LL ijij = Load between departments i & j, often measured = Load between departments i & j, often measured by the value of the Vowel Letter.by the value of the Vowel Letter.A = 4, E = 3, I = 2, O = 1, U = 0, X = -1A = 4, E = 3, I = 2, O = 1, U = 0, X = -1
DDijij = Distance between departments i & j (move only = Distance between departments i & j (move only at Right angles)at Right angles)
*Many Variations of this Concept*Many Variations of this Concept
8. 8. Space Relationship DiagramsSpace Relationship Diagrams
9.9. LayoutsLayouts
45
Department Pair
1-21-31-41-51-61-72-32-42-52-62-73-43-53-63-74-54-64-75-65-76-7
Lij
20014030212-11-1-1043000
Dij
202313121113222311222
Zij
40034030212-32-2-2043000
7. 7. Diagram Score:Diagram Score:
21
46
Types of LayoutsTypes of Layouts
Product
CM
Job-Shop (process)
Number of Part Numbers
(P)
(Q)
Number of pieces/part#
47
PRODUCT LAYOUTPRODUCT LAYOUT
Product Layout: Continuous Flow Production SystemProduct Layout: Continuous Flow Production System
Definition: Layout is dictated by the product. (P)
Suited to manufacturing processes with single output
Equipment arrangement operation sequence
High production (volume) items and stable demand, similar products:
48
PRODUCT LAYOUTPRODUCT LAYOUT
Materials move by Materials move by unitsunits in a product line, not by lots. in a product line, not by lots.
UNIT1. 2. 3.
*?
demand
Operations performed at various workstations
*The Output is determined by the slowest operation
TASK is to BALANCE the workstations in terms of the work done (time) and satisfy the required
output.
*
49
PRODUCT LAYOUTPRODUCT LAYOUT
Two Types of ProblemsTwo Types of Problems:: Required Information:
Fabrication Lines
Assembly Lines
Sequence of operations or job elements
Time required for each operation or independent element
Output required
(R)
(T)
(Q)
50
EXAMPLEEXAMPLE
Design a fabrication line to manufacturing a product Design a fabrication line to manufacturing a product with the following 7 operations. Initially assume:with the following 7 operations. Initially assume:
No scrap losses
100% eff. & 480 min/day
1000 units required per day
51
EXAMPLEEXAMPLE
Specifically determineSpecifically determineA)A) The number of machines required at each The number of machines required at each workstation, andworkstation, andB)B) The % of idle time for the following operations:The % of idle time for the following operations:
Opn #
1234567
Operation
SawCenter
Turn (RGH)Heat TreatFin Turn
GrindMill
52
OUTPUT REQ’D: 1000 UNITS/DAYOUTPUT REQ’D: 1000 UNITS/DAY
A
B
C
D=A*B*C
Std Time (Output)
Opn Std Time Cont. Output Machines Req’d
Theoretical Prod. Time
Actual Prod. Time
1 2 3 4 5 6 7 Totals
1.20 min 0.80 min 1.00 min 2.40 min 0.40 min 3.00 min 1.20 min 10.0 min
400 pcs 600 pcs 480 pcs 200 pcs 1200 pcs 160 pcs 400 pcs per machine
3 2 3 5 1 7 3
1440 min 960 min 1440 min 2400 min 480 min 3360 min 1440 min 11,520 min
1200 min 800 min 1000 min 2400 min 400 min 3000 min 1200 min 10,000 min
Idle =11520-10000
1152013.2%
53
OUTPUT REQ’D: 1200 UNITS/DAYOUTPUT REQ’D: 1200 UNITS/DAY
Opn Number of Stations
Theo. Time Act. Time
1 2 3 4 5 6 7
3 2 3 6 (+1) 1 8 (+1) 3
1440 960 1440 2880 480 3840 1440 12,480
= = > = = > =
1440 960 1200 2880 480 3600 1440 12,000
Idle =12480-12000
124803.8%
54
OUTPUT REQ’D: 800 UNITS/DAYOUTPUT REQ’D: 800 UNITS/DAY
Opn Number of Stations
Theo. Time Act. Time
1 2 3 4 5 6 7
2 (-1) 2 2 (-1) 4 (-1) 1 5 (-2) 2 (-1)
960 960 960 1920 480 2400 960 8640
= = = = > = =
960 640 800 1920 320 2400 960 8000
Idle =6408640
7.4%
55
SUMMARYSUMMARY
Output Rate
Total Number Of Machines
% Idle
800 900
1000 1100 1200 1300 1400 1500
18 22 24
26
7.4 14.7 13.2
3.8
CONCLUSIONS:
56
INVENTORIESINVENTORIES
Now how does one handle the idle time which occurs?
*i.e., complete balance not possible.
Ans. Work in-process inventories are used to “decouple” operations.
Slack for machine breakdowns
InvenStat 1
InvenStat 2
Stat 3
57
SYSTEM UTILIZATION LEVELSSYSTEM UTILIZATION LEVELS
Production Level (pcs/hr)
Stat No. Hourly Capacity per “Machine”
40 55 60 80
1 2 3 4 5
55
40 85
105
60
73%
100% 47% 38%
67%
100%
2) 69% 65% 52%
92%
2) 55%
2) 75% 71% 57%
100%
2) 73%
2) 1005 94% 76%
2) 67%
Avg. Util. Add’l Mach.
New Util.
65% 2
54%
75% 1
64%
70% 5
61%
81% 2
72%
58
How to Handle ScrapHow to Handle Scrap
What inputs are required at each station?What inputs are required at each station? How many machines are required at each station?How many machines are required at each station?
Station 1 Station 2 Station 3?
Operation Std. Time (min/part)
Scrap% Efficiency%
1 0.3 5 0.9
2 0.5 3 1.05
3 1.1 4 1.00
150 pcs/hr
59
TERMSTERMS
Inputn =Outputn
(1.00-Scrapn)
Efficiency =Std. Time
Actual TimeX 100%
60
Station #3
150Input
Std Time = 1.1 min/pc. 54.5 pcs/std. hr.
Input =150
(1-.04)= 156.25 = 157
x 1.00 Eff.
54.5 54 pc/hr./machine
2.91
157/54 3 machines
61
Station #2
157
Std Time = .5 min/pc. 120 pcs/std. hr.
Input = =
x 1.05 Eff.
126 pcs/hr./machine
162/126 = 1.28 2
2
62
Station #1
Std Time = .3 min/pc. 200 pcs/std. hr.
Input = =
171/180 = .95 1
x .90 Eff.
180 pcs/hr./machine
63
Operation Actual production
rate (part/hr) per
Mc
Production time (min)
per Mc
Mc Theoretical time (min)
Idle time (min)
1 180 57 1 60 3
2 126 77.14 2 120 42.86
3 54 174.44 3 180 5.56
Total 308.58 360 51.42
Idle = (360 - 308.58)/360 = 0.143
Utilization = 1 - 0.143 = 0.857
64
Final LayoutFinal Layout
171162 157
12
3
150
65
Class ProblemClass ProblemA circuit line consists of four processes:
A: chip production,B: assembly,C: test, andD: package.
Three chips go into every assembly.
The production and scrap rates are as follows:
What is the output rate of this line?
Process Production Rate(Pcs/hr)
Scrap (%)
ABCD
200605570
151050