Plant Layout 1g5y5s

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MEANING & DEFINITION V Physical arrangement of production facilities. V Moore:- ³ plant layout is a plan of an optimum arrangement of facilities including personnel, operating equipment, storage space, material handling equipment & all other ing services along with the design of best structure to contain all these facilities.´ V Overall objective :- to design a physical arrangement that meets the requirement of output quantity & quality.

PLANT LAYOUT ï Problems of plant layout:V Everyone in the organization is associated with plant layout. V Reasons for change of plant layout:V V V V V V V

Change in product design or launch of new product. Change in volume of demand for the company¶s product. High rate of accidents due existing plant layout. Outdated plant & machinery, need for salvage. Poor working environment affecting efficiency & productivity. Change in location or market. Minimizing cost through effective facilities planning.

PLANT LAYOUT ï Objectives of plant layout:V Primary objective :- to maximize profit by arrangement of all facilities to the best suitability of manufacturing. V Streamline flow of material through plant. V Facilitate manufacturing process. V Maintain high turnover of in- process inventory. V Minimize material handling. V Effective utilization of men, machine & space. V Effective cubic space utilization V Flexibility of manufacturing. V Provision of employee safety, convenience & comfort.

PRINCIPLES OF PLANT LAYOUT ï PRINCIPLE OF INTEGRATTION :- A GOOD LAYOUT INTEGRATES ALL RESOURCES- MEN,MACHINE,MATERIAL IN ORDER TO GET OPTIMUM UTILISATION & MAXIMUM EFFECTIVENESS. ï PRINCIPLE OF MINIMUM DISTANCE:- MINIMUM TRAVEL WITH MEN & MATERIAL. FACILITIES SHOULD BE ARRANGED IN SUCH A WAY THAT TOTAL DISTANCE TRAVELLED BY MEN, MATERIAL & EQUPMENT SHOULD BE MINIMUM & IN STRAIGHT LINE. ï PRINCIPLE OF CUBIC SPACE UTILIZSATION :- A GOOD LAYOUT IS ONE WHICH USES BOTH HORIZONTAL & VERTICAL SPACE. EFFECTIVE USE OF HEIGHT DIMENSION ALONG WITH FLOOR SPACE .

PRINCIPLES OF PLANT LAYOUT ï Principle of flow:- material should move in forward direction towards completion without backtracking. ï Principle of maximum flexibility:- a good layout is one that can be altered without much efforts & cost. Future expansion should be taken into consideration. ï Principle of safety, security & satisfaction:- give due consideration to workers safety & satisfaction, safeguard of plant & machinery against fire, theft etc. ï Principle of minimum handling:- material handling reduced to minimum.

ADVANTAGES OF GOOD PLANT LAYOUT V Advantages to workers:-

- reduced efforts of workers in travel. - Minimizes material handling - Provides convenient & comfortable working conditions - Minimizes accidents. V Advantages in manufacturing: -

- reduced material travel distance & time. - Avoidance of bottlenecks in production. - Less delay in production ; reduced cycle time - Increased productivity.

PLANT LAYOUT Ñ Advantages in production control:- Uniform & uninterrupted flow of material - Production completed without excess man & material travel & material handling within scheduled time. Ñ Advantages to management:- Reduced labour cost. - Reduced material handling cost. - Economics in material handling. - Effective land, space utilization. - Effective man, machine utilization. - Minimum capital investment. - Reduced cost per unit - Increase in market competitiveness

PLANT LAYOUT ï Factors influencing plant layout:V Type of production:- engineering / process industry V Type of production system:- job/batch / mass V Volume or scale of production V Variety of product mix V Available total area. V Availability & arrangement of material handling system. V Type of building:- single or multi-storey / shed. V Scope or plans for future expansion or diversification. V Types of production facilities- GPM or SPM.

PLANT LAYOUT Ñ Types of layout:Ñ 1) Block Layout :- arrangement of different production & all other facilities within the premises of factory taken as blocks. It includes production area, security, dispatch , canteen, maintenance, istration office etc. Ñ 2) Shop Layout:- detailed arrangement of each facility represented by block in block layout. Ñ 3) Workplace layout:- in a shop, the detailed arrangement of each workstation, storage area, material in & outflow area near work station ,arrangement of tools, jigs, dies fixtures, components, subassemblies etc. is elaborated in workplace layout.

PLANT LAYOUT V Types of plant layout:V 1) layout by fixed position:V Also called project layout. V Material, major components remain in a fixed location, and tools, machinery, men & other material are brought to the location of job. V Suitability:- for project jobs such as :- ship vessels, pressure vessels, huge air crafts. TOOLS

MACHINES

RAW MATERIAL

MANPOWER

PRODUCT

PLANT LAYOUT V Advantages:V V V V V V V

Minimum capital investment in plant layout Less material movement Continuity of operations Less total production cost Greater flexibility Job enlargement & upgrades skill of operators Sense of attachment with job

V Disadvantages:V Machines, tools take more time to reach workplace. V Highly skilled workers are required V Complicated jigs/fixtures are required.

PLANT LAYOUT V 2) Functional Layout( Process Layout) :V Recommended for batch / lot production. V Each department is responsible for carrying out a particular process /function on the job and not for a particular product. V All machines/equipment performing similar type of operations are grouped at one location forming a section. V Machines are placed on a functional basis . V For ex.:- All lathes, milling m/c are grouped in the shop will be clustered together. V The flow of material from a workstation to other varies from product to product. V Usually material travel paths are long with backtracking.

PLANT LAYOUT V PROCESS TYPE LAYOUT

MILLING SECTION

WELDING SECTION

LATHE SECTION

GRINDER SECTION

HEAT TREATMENT SHOP

INSPECTION DEPT.

RECEIVING AREA

ASSEMBLY SHOP

PAINTING SHOP

SHIPPING DEPT.

PLANT LAYOUT V PROCESS LAYOUT FOR MULTIPRODUCTS: ¦









¦ ¦

¦









PLANT LAYOUT V Advantages:V Flexibility of equipment & personnel. V Comparatively less no. of GPM, low plant cost ; V Less capital investment in plant layout . V Higher utilization of production facilities. V Greater flexibility as regards to work distribution of men & machine& also volume of production. V Succession of operations is not suffered due to breakdown of one machine. V Variety of jobs make the job challenging & interesting. V Supervisors are knowledgeable & workers are skilled.

PLANT LAYOUT V Disadvantages:V Long material movements may occur as per product functional or process requirement. V Backtracking of material may occur as per job process. V Thus material handling efficiency is reduced. V Process cycle time is prolonged. V Production planning & control is difficult. V More in process inventory; less inventory turn over. V More set-up time; low productivity. V Requires more space due to lack of automate material handling. V More time in inspection as it is necessary after each process

PLANT LAYOUT V Product Layout ( Line Layout):V Machines are arranged as per the sequence required by the product. V Special purpose machines are used for quick, specific & reliable operation on the job. V Mostly used in mass production. V Ex.:- Sequence of operation required is turning, milling, drilling, assembly, inspection ,packing & dispatch. RAW MATERIAL

LATHE

MILLING

DRILLING

ASSEMBLY

INSPECTION

PRODUCT

PACKAGE & DESPATCH

PLANT LAYOUT V PRODUCT LAYOUT FOR MULTIPRODUCTS:

















PLANT LAYOUT V Advantages:V Mechanized or automated material handling. V Less material travel distance as machines are closely spaced & in sequence of operations. V Less material handling time & cost. V Perfect balancing offline is done which eliminates bottlenecks & idleness. V Forward & simplified material flow towards completion. V No backtracking. V Simplified production planning & control. V Less work in process inventory; more inventory turnover. V Unskilled workers can manage production. V Cycle time is reduced ; productivity is increased.

PLANT LAYOUT V Disadvantages:V Lack of flexibility as layout is for specific product with spms laid down in order to fulfill required sequence of operations for that particular product. V Large capital investment as cost of SPMs is high. V Breakdown of any machine can stop the production line. V Operators are not skilled , they learn specific operation to be performed on a certain machine.

PLANT LAYOUT V COMPARISON BETWEEN PRODUCT & PROCESS LAYOUT:SR.NO.

CHARACTERISTIC

PRODUCT LAYOUT

PROCESS LAYOUT

1

NATURE

SEQUENCE OF MACHINES

GROUPING OF MACHINES

2

APPLICATION

HIGH VOLUME, FEW PRODUCTS

HIGH VOLUME & VARIETY

3

PRODUCT

STANDARDISED

DIVERSIFIED

4

WORKFLOW

STRAIGHTLINE

VARIABLE

5

MATERIAL HANDLING

MECHANISED

NON AUTOMATED

6

INVENTORY

LOW WIP

HIGH WIP

7

BREAKDOWNS

STOPS PRODUCTION

CAN BE TOLERATED

8

PRODUCION CENTRE

SIMPLE

COMPLEX

9

FLEXIBILITY

LOW

HIGH

10

SPACE UTILISATION

EFFICIENT

LOW

11

PRODUCT COST

HIGH FIXED COST , LOW VARIABLE COST

LOW FIXED COST, HIGH VARIABLE COST

PLANT LAYOUT V COMBINATION / HYBRI D LAYOUT:-

V Mixed type in which process layout is combined with product layout. V Various components are produced by process layout. V Assembly of finished components is by product layout. V Combines merits of both types. V Ex.:- Manufacture of refrigerator. Functional layout to produce various operations like stamping, welding, heat treatment at various workstations & final assembly is done by product layout.

PLANT LAYOUT V COMBINATION LAYOUT (HYBRID / MIXED LAYOUT)

V Pure product or process layout is not seen in industries. V A process layout is combined with product layout V Ex.:-1) a plant involving fabrication & assembly of parts. V Fabrication is in process layout & assembly in product. V Refrigerator , washing machine manufacturing. V Soap manufacturing ± processing all ingredients is by process layout. Mixing of

ingredients, molding of soap, packing are in product layout. ROTOR

PROCESS LAYOUT

MOTOR HOUSING

PROCESS LAYOUT

BEARING HOUSINGS

PROCESS LAYOUT

BEARING COVERS

PROCESS LAYOUT

END COVERS

PROCESS LAYOUT

MOTOR ASSEMBLY LINE PRODUCT LAYOUT

PLANT LAYOUT Ñ Group Technology (GT) Layout:Ñ Trend to bring element of flexibility in manufacturing system as regards to variation in batch size & sequence of operations. Ñ Grouping of equipment performing a sequence of operations on a family of similar components / products is essential. Ñ Items are grouped into families. Ñ Family :- Components which undergo same sequence of operations ( follow same path) Ñ Two basic steps:- 1) Determine component families. 2) Arrange equipment to process each family of components. Ñ Represents plant within plant. Ñ Reduces planning time, set-up time for jobs.

PLANT LAYOUT Ñ Types of gt layout:1) Group GT Layout:Ñ Ñ Ñ Ñ

All machine tools required for processing all components in a family are arranged in a cell. All components may not be processed on all machines but complete processing is achieved in a cell. All components do not follow exactly identical path. Example:- gear box housing cell

PLANT LAYOUT GROUP GT LAYOUT:-

V

All components do not follow exactly identical path. CELL

RAW HOUSING A

RAW HOUSING B

RAW HOUSING C

M/C. 1

M/C. 1

M/C. 1

M/C. 1

2

2

5

2

3

3

4

3

4

4

3

5

5

5

2

4

CELL PRODUCT

FINISHED HOUSING A

FINISHED HOUSING B

FINISHED HOUSING C

PLANT LAYOUT GROUP GT LAYOUT:-

V

All components may not be processed on all machines. CELL

RAW HOUSING A

RAW HOUSING B

RAW HOUSING C

M/C. 1

M/C. 1

M/C. 1

M/C. 1

2

2

--

--

3

3

3

--

4

--

4

4

5

--

--

5

CELL PRODUCT

FINISHED HOUSING A

FINISHED HOUSING B

FINISHED HOUSING C

PLANT LAYOUT 2) Line GT Layout:Ñ All machine tools required for processing all components in a family are arranged in a cell. Ñ

All components are processed on each machines & follow exactly identical path

Ñ

Complete processing is achieved in a cell.

Ñ

Example:- Gear box housing cell

PLANT LAYOUT

CELL

RAW HOUSING A

RAW RAW HOUSING B HOUSING C

M/C.1

M/C.1

M/C.1

M/C.1

2

2

2

2

3

3

3

3

4

4

4

4

5

5

5

5

CELL PRODUCT

FINISHED HOUSING A

FINISHED FINISHED HOUSING B HOUSING C

PLANT LAYOUT Example :- 3 motor models A,B &C Main families :- Shaft/Rotor, Motor Housing, Bearing Housings, Bearing Covers, end covers. ROTOR CELL

HOUSING CELL

BEARING HOUSING CELL

BEARING COVER CELL

COMPONENTS OF A,B,C

MOTOR ASSLY

TESTING,STORAGE & DESPATCH

END COVER CELL

PLANT LAYOUT V Advantages:V Brings out element of flexibility in manufacturing system as regards to batch size and sequence of operation. V Technique very useful for companies that produce variety of parts in small batches to ensure uninterrupted assembly. V Reduces production planning for jobs V Reduces set up time.

PLANT LAYOUT Ñ Material Flow Patterns:- coordinated material movement from start to finish. Ñ Types:- 1)Horizontal:- for single storey building , flat floor space

is available. 2) vertical:-for multistoried plant building . cubic space utilization. A) PRODUCTION LINE FLOW PATTERNS:1) STRAIGHT LINE ( I) FLOW PATTERN:Ñ Simplest of all .Plant area has longer length & shorter width. Not suitable for long production lines. Total handling distance is minimum. Convenient for ³I ´ shaped buildings. Ex.:- Automobile plants. Ñ

START

FINISH

PLANT LAYOUT 2) I-Flow Pattern:V Recommended where i patterns are not suitable. V For longer production line. V Occupies less space. 3) U-Flow Pattern:V Suitable for longer production lines. V Requires square floor area. V Permits receiving & shipment on same side of plant. V Better security checks. 4) S-Flow Pattern:- (Inverted S or Serpentine) V Suitable if line length longer than building length. V Compact arrangement. V Easy supervision V Receiving & shipment on opposite sides.

PLANT LAYOUT 5) O ±Flow Pattern :- Suitable for operations are performed on rotary table. Component traverses circular path as it moves from one workstation to other & leaves as finished product. V Ex.:- Manufacture of electric bulbs.

U-FLOW LINE

L-FLOW LINE

S-FLOW LINE

PLANT LAYOUT B) Assembly Line Flow Pattern:1) Comb Pattern:Ñ Feed to main assembly line is from no. Of sub assembly lines located on one side of main assembly line. Ñ Main assembly line is on wall side or along aisle. 2) Tree Pattern:Ñ Sub assembly lines located on both sides of main assembly line give feed to main assembly line. Ñ Shorter than comb pattern for same no. Of sub assembly lines. 3) Dendritic Pattern:Ñ Parts combine to form subassemblies. Ñ Subassemblies combine with other subassemblies or parts to form progressive assemblies which leads to final main assembly.

PLANT LAYOUT 5) Overhead Flow Pattern:V The flow starts from upper floors to ground floor. V For multistoried plants. V Final main assembly is on ground floor.

COMB PATTERN DENDRITIC PATTERN

TREE PATTERN

PLANT LAYOUT Ñ C) Machine Arrangements Patterns:1) Straight Line Arrangement:-

Axis of machines is parallel to adjacent aisle. Ñ Normally two rows of machine on each side of aisle . 2) Diagonal Arrangement:Ñ Axis of machines is inclined to the aisle. Ñ More no. Of machines accommodated in given area. Ñ Narrow aisle is sufficient. Ñ Material receipt & removal are from either sides of m/c. 3) Circular Arrangement:Ñ When one operator operates more than one machine. Ñ Operator at centre & workstations at circumference. 4) Odd Angle Arrangement :- Convenient feed to m/c. Ñ

PLANT LAYOUT V PROCEDURE OF PLANT LAYOUT:-

V Analysis of product to be produced. V Determine process required & its sequence to manufacture the product. V Prepare layout planning chart s:- flow process charts, V V V V V V V

Time estimation, machine selection & balancing , manpower etc. Determine type & no. of workstations / machines required . Determine storage area required for each workstation. Determine minimum aisle width. Determine office area required. Consider personnel facilities & services. Consider plant services. Make provision for future expansion.

PLANT LAYOUT Ñ DATA TO BE COLLECTED FOR DESIGN OF A GOOD LAYOUT:-

Ñ Processes of operation Ñ Sequence of operations of each process Ñ Material flow Ñ Frequency of travel Ñ Space required & available area. Ñ Activities & their relation or dependence.

PLANT LAYOUT Ñ TECHNIQUES USED TO COLLECT & ANALYSE DATA:-

Ñ Process Charts :- 1) Operation Process Charts

2) Flow Process Charts V Travel chart Ñ REL chart Ñ Templates Ñ Models Ñ Computer Aided Layout Planning (CALP) Ñ Flow diagram Ñ String diagram

PLANT LAYOUT V TRAVEL CHART :-

V It is a from ± to chart V Records & indicates movement of material between two workstations or departments. V Helps to determine degree of closeness between two departments or workstations. V Basic tool in layout design V Achieves principle of minimum travel & hence material handling cost. V Advantages:V Useful for movement analysis, V Helpful to locate activities & backtracking V For comparing alternative layout. V Can be easily computerized.

PLANT LAYOUT V METHOD:-

V List departments both row & column wise in same sequence. V Each intersecting square is called a cell. V Note movement from one to other department in cell V Ex.:- MBC ± movement from dept. B toCc V Place entries on either side of diagonal in cell.

DEPT.

A

B

C

A B C D E F

MBC

D

E

F

PLANT LAYOUT V Relationship Chart (REL chart):V Displays relative importance of placing one department near another. V Each diamond shaped cell in the chart shows type of relationship between two functional departments. V There are two entries in each cell. V The top letter indicates the degree of closeness between two departments. V The no. below indicates the reason for that relationship. V The diagram explores relatedness of departments rather than calculating exact flow and costs. V This rating of required closeness of the department pairs is used to develop a proposed layout

PLANT LAYOUT

DEPT. 1 DEPT. 2 DEPT. 3 DEPT. 4 DEPT.5 DEPT. 6

I U X O U

U

A E

E I U

E E

X I VALUE

DEGREE OF CLOSENESS

A

ABSOLUTELY ESSENTIAL

1

4

E

ESPECIALLY IMPORTANT

5

2

I

IMPORTANT

3

6

O

ORDINARY CLOSENESS

U

UNIMPORTANT

X

NOT DESIRABLE

PLANT LAYOUT V COMPUTER AIDED LAYOUT PLANNING:V Computerized layout analysis increases the speed and accuracy of evaluation of

various alternatives. V CRAFT ( COMPUTERIZED RELATIVE ALLOCATION OF FACILITES):-

V Input:- Material flow per unit time, Cost per unit per unit V V V V V V

distance moved, Space requirements It is an improvement algorithm Limitations:- maximum 40 departments Considers exchange between locations repeatedly until no further significant cost reductions are possible. Output:- in the form of facilities in a basic rectangular form with lowest cost. Assumes that movement between department occurs along straight line between centroids of the departments. Assumes that cost varies linearly with distance.

PLANT LAYOUT V COMPUTER AIDED LAYOUT PLANNING:V CORELAP ( COMPUTERIZED RELATIONSHIP LAYOUT PLANNING):-

V Uses A,E,I,O,U,X closeness ratings, Space requirements and Maximum building length to width ratio to develop a layout. V Input:V No. of departments and area requirements V Relationship chart. V Weightage for REL chart. V Maximum building length to width ratio. V ALDEP (AUTOMATED LAYOUT DESIGN PROGRAMME) :-

V Requires input data for building specifications. V Preference matrix for location relationships. V Capacity of laying out up to 63 departments.