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Layout for manufacturing facilities

Facility layout means planning for the location of all machines, utilities, employee

workstations, customer service areas, material storage areas, aisles, rest rooms, lunchrooms,

drinking fountains, internal walls, offices, and computer rooms, and for the flow patterns ofmaterials and people around, into, and within buildings. Through facility layouts, the

physical arrangement of these processes within and around buildings, the space necessary forthe operation of these processes, and provided the space required for support functions. As

process planning and facility layout planning information continuous interchange betweenthese two planning activities, because each affects the other

Some Objectives of Facility Layouts

There are many objectives of facility layouts these are:-

1- objectives for manufacturing operation layouts

* rovide enough production capacity.

* !educe materials-handling costs .

* "onform to site and building constraints .

* Allow space for production machines.

* Allow high labor, machine, and space utili#ation and productivity.

* rovide for volume and product fle$ibility.

* rovide space for rest rooms, cafeterias, and other personal-care needs of employees .

* rovide for employee safety and health.* Allow ease of supervision .

* Allow ease of maintenance.

* Achieve objectives with least capital investment.

2- additional objectives for Warehouse operation layouts

* romote efficient loading and unloading of shipping vehicles.

* rovide for effective stoc% pic%ing, order filling, and unit loading.

* Allow ease of inventory counts.* romote accurate inventory record %eeping.

3- additional objectives for service operation layouts

* rovide for customer comfort and convenience .

* rovide appealing setting for customers.

* Allow attractive display of merchandise.

* !educe travel of personnel or customers.

* rovide for privacy in wor% areas.

* romote communication between wor% areas.* rovide for stoc% rotation for shelf life.

&- additional objectives for office operation layouts

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* !einforce organi#ation structure.

* !educe travel of personnel or customers.

* rovide for privacy in wor% areas.

* romote communication between wor% areas.

the objective of the facility layout study is to minimie total cost! this cost"-

(') "onstruction cost.() +nstallation cost.() aterial handling cost.(&) ase of future e$pansion.(/) roduction cost.

(6) Machine downtime cost.

(7) In-process storage cost.

(8) Safety cost.(0) ase of supervision.

Layout for manufacturing facilities

There are five basic types of layouts for manufacturing facilities 1process, product, cellularmanufacturing(") , fi$ed position and 2ybrid 3ayouts :

'-process layouts # functional layouts! or job shops$

are designed to accommodate variety in product designs and small batches .rocess layout usegeneral 4purpose machines that can be changed over rapidly to new operations for different

product designs. these machines are usually arranged according to type of process beingperformed.

for example , all machining would be in one department ,all assembly in anther department,and all painting in anther department ,the materials 4handling equipment generally consists offor%lift truc%s and other mobile vehicles that allow for the variety of paths followed through thefacility by the products produced.the wor%ers must change and adapt quic%ly to the multitude of operations to be performed oneach unique batch of products being produced. These wor%ers must be highly s%illed 5 requireintensive job instructions And technical supervision.rocess layout require ongoing(continues) planning, scheduling, and controlling functions toensure an optimum amount of wor% in each department and each wor%station. +nventory in

process is large, the products are in the production system for relatively long period of time.


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2-prduct layout#production lines or assembly lines $

are designed to accommodate only a few product designs. the machinery or equipments isarranged to ensure continuous flow of material in an orderly mode throughout the plant. e$amples of product layout, aper mills, dairies, cement factories, and automotive assembly

plants , Auto manufacturing.

product layout use speciali#ed machines that are set up once to perform a specific operation for along period of time on one product, this machines requires great e$pense and long down times Tochange over to a new product design.companies that produce only a few product types often set up a different production line for each

product type. The facility layout would allow for the different product lines to separated fromeach other.6or%ers repeatedly perform a narrow range of activities on only a few product designs5 requireda small rate of s%ill, training and supervision .The planning and scheduling activities are comple$ ,they are not ongoing(continuous), rather

planning 5 scheduling tend to be done intermittently as product changeovers occur. The primary

objective is to minimi#e material handling cost by properly arranging the equipment in the

processing sequence. any types of flow are possible. below only a few.


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%rocess Layout

&dvantages

'. etter utili#ation of machines can result1 consequently, fewer machines are required.

. A high degree of fle$ibility e$ists relative to equipment or manpower allocation for specifictas%s.. "omparatively low investment in machines is required.&. The diversity of tas%s offers a more interesting and satisfying occupation for the operator.

/. 7peciali#ed supervision is possible.

Limitations

'. 7ince longer flow lines usually result, material handling is more e$pensive.. roduction, planning, and control systems are more involved.. Total production time is usually longer.&. "omparatively large amounts of in-process inventory result./. 7pace and capital are tied up by wor% in process.8. ecause of the diversity of the jobs in speciali#ed departments, high grades of s%ill are required.

3- ellular manufacturing layouts#.$

machines are grouped into cells, and the cells function somewhat li%e a product layout islandwithin a larger shop or process layout .(fig &.9) each cell in a " layout is formed to produce a

single parts family (a few parts all with common characteristics) ,they require the same machinesand have similar machine settings. Although the cell layout can ta%e on many different forms, theflow of parts more li%e a product layout than a job shop. " layout would be attempted for thesereasons:

'-achine changeovers are simplified.

- Training periods for wor%ers are shortened.

-aterials-handling costs are reduced.

&- arts can be made faster and shipped more quic%ly.

/- required 3ess in-process inventory.

8- roduction is easier to automate.

+n developing a " layout, the first step is the cell formation decision, the initial decision aboutwhich production machines and which parts to group into a cell. ;e$t, the machines are arranged

within each cell.

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4- Fi5ed-%osition Layouts

7ome manufacturing and construction firms use a layout for arranging wor% that locates the

product in a fi$ed position and transports wor%ers, materials, machines, and subcontractors to

and from the product.


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6- 7ybrid Layouts

ost manufacturing facilities use a combination of layout types) 2ybrid 3ayouts(uring final assembly, each

aircraft unit is located in a fi$ed-position assembly bay. 2owever, every two or three days eachaircraft unit is rolled out of its bay and pushed into the ne$t assembly bay, where different

assembly tas%s are performed. 7o, even though an aircraft is assembled for two or three days at a

time in a fi$ed position, it passes through si$ or eight different assembly bays in a product layout

fashion.it is important to understand the characteristics, advantages, and disadvantages of each basic type

of layout.

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)e8 *rends in .anufacturing Layouts

?.7. manufacturers= layouts have been traditionally designed for high wor%er and machine

utili#ation, whereas modern layouts are designed for quality and fle$ibility, the ability to quic%ly

shift to different product models or to different production rates.

As ?.7. facilities move toward modern layouts, these trends in layouts can be observed:

* "ellular manufacturing layouts within larger process layouts.

* Automated materials-handling equipment, especially automated storage and retrieval systems,

automated guided vehicle systems, automatic transfer devices, and turntables.

* ?-shaped production lines that allow wor%ers to see the entire line and easily travel between

wor%stations. This shape allows the rotation of wor%ers among the wor%stations along the lines torelieve boredom and relieve wor% imbalances between wor%stations. Additionally, teamwor% and

improved morale tend to result because wor%ers are grouped in smaller areas and communication

and social contact are thereby encouraged.

* ore open wor% areas with fewer walls, partitions, or other obstacles to clear views of adjacent

wor%stations.* 7maller and more compact factory layouts. 6ith more automation such as robots, less space

needs to be provided for wor%ers. achines can be placed closer to each other, and materials and

products travel shorter distances.

* 3ess space provided for storage of inventories throughout the layout.

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*raditional facility layout versus modern layout

1- haracteristics of *raditional Layouts

* Chief objective#92igh machine and wor%er utili#ation.* eans of achieving objective"3ong production runs, fi$ed job assignments for wor%ers in orderto reali#e speciali#ation-of-labor benefits, inventory to guard against machine brea%downs,constant production rates and with defects set aside for later rewor%, and large productionmachines that are %ept fully utili#ed.

* !ppearance of layouts"ery large manufacturing-plant floor plans, e$tensive areas reserved forinventory, much space used for long conveyors and other materials-handling devices, large

production machines requiring much floor space, 3-shaped or linear production lines, and

generally underutili#ed floor space.

2- haracteristics of .odern Layouts

*Chief objective"roduct quality and fle$ibility, the ability to modify production rates quic%ly andto change to different product models.

*eans of achieving objective"6or%ers trained at many jobs, heavy investment in preventivemaintenance, small machines easily changed over to different product models, wor%ers encouragedto e$ercise initiative in solving quality and other production problems as they occur, wor%ers andmachines shifted as needed to solve production problems, production lines slowed down andmachine brea%down or quality problems solved as they occur, little inventory carried, andwor%stations placed close together.*!ppearance of layouts"!elatively small manufacturing-plant floor plans, compact and tightly

pac%ed layouts, large percentage of floor space used for production, less floor space occupied by

inventory or materials-handling devices, and ?-shaped production lines.

"xample

The 6hittemore >airy of


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6e assume that the objective is to minimi#e material handling cost by placing interacting

departments as close together as possible. +n an industry such as a dairy, the distances

between departments may not be as important as in other industries because almost all

material handling up to the pac%ing stage is done through pipes. This required the longer

pipes, more equipment and energy. Therefore, minimi#ing distance will minimi#e material

handling cost. Therefore, a total layout analysis is necessary.

To solve this problem we e$am three essential types of layouts: product, process, and fi$ed-

position. roduct layout is useful in a mass-production situation. rocess layout is necessary

in job-lot production. airy e$ample there are only a few products produced and almost all follow the

same essential process lines .


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Lecture#:$

Systematic Layout %lanning #SL%$

7ystematic layout planning is an organi#ed approach to layout planning


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procedure is the preparation of process charts graphically depicting the flow of the material

through the plant. +f there are a few products, we made separate operations process chart for

each product. +f there are many products, we use a multiproduct process chart. Actually, an

operation process chart depicts only the operations and inspections5 the flow process chart

shows operations and inspections, transportations, delays, and storages. +n the operations

process chart (fig.8.&)

airy

a line is drawn at the upper right-hand corner of the paper reflecting the start of the largest

component. Dther parts of materials are fed in from the left. The sequence is from top to

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bottom and only shown. operations and inspections.


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often layouts can be constructed on the basis of this flow alone. +n the dairy e$ample, almostall areas can now be laid out according to the operations process charts (


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+n many situations, , some areas do not have any product flow and flow sequence differs for

each of several products. +n the dairy e$ample the laboratory equipment, restroom, and metal

crate areas do not have product flows at all. Also, the flow of cottage cheese and buttermil% is

different from that of mil% and juice.

Step 2 in SL%#activity relationship$

is the preparation of an activity relationship diagram that shows the desired closeness of

departments and areas within the plant activity relationship diagram not shown all important

relation ships by product flows ;

For e5ample

it is desirable for the quality control lab in a dairy to be located as close to the processing

area as possible and for the restroom facilities to be far away from the mi$ing vats in the

processing area.


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Step 3 in SL%#String 'iagram$

involves using the information generated in steps ' and to prepare a string diagram

showing near optimal placement of the facilities without consideration of space

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requirements.


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omputeried Layout %lanning #Optional$

computeri#ed layout pac%ages ta%e the activity relationship charts developed in 7tep or

from-to charts developed in step ' (depending on which pac%age is used) and generate any

specified number of layouts. These can be scored and compared by the computer andMor the

layout analyst. The final decision must be made by the manager. The chief advantage in

computeri#ed pac%ages is generated the large number of alternatives .

There are many computeri#ed plant layout pac%ages available, A3>, "D!3A, and

"!A and "D!3A are NconstructionN types in that layouts are

generated from scratch. "!A

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