END 202END 202Work Analysis and Design
F ili L‐ Facility Layout ‐(Mostly from M.P. Groover’s book.)( y )
Sibel ALUMUR ALEVSibel ALUMUR ALEV
February 2011
END 202 – Work analysis and design Facility Layout
Definition
• Facility layout refers to the size and shape of a facility as well as the relative locations and shapes of functional areas, departments, equipment, workstations, storage spaces, aisles, common areas in it.
• Facility layout includes all types of facilities: plants, warehouses, distribution centers, office buildings, hospitals,…
• Plant layout is focused on production plants
END 202 – Work analysis and design Facility Layout
Facility layout
• The layout of a facility is an important factor in determining the overall efficiency and g yeffectiveness of the production or service operationsoperations
• A poor layout can result in inefficient work fl h k f kiflows, unhappy workers, unsafe working conditions, and less capacity to carry out the
l f h f loperational mission of the facility
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Facility layout
• A well designed layout should satisfy the following objectives:
– Efficient movement of materials and people– Logical work flow and minimum travel distances
between operationsbetween operations– Efficient utilization of space– Safety and satisfaction of workers and others who– Safety and satisfaction of workers and others who
use the facility– Flexibility to meet changing future requirementsy g g q– Advancing the operational mission of the facility
END 202 – Work analysis and design Facility Layout
Outline
• Types of production plant layoutsTypes of production plant layouts
• Other types of layoutsOther types of layouts
• Systematic layout planningSystematic layout planning
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Types of plant layouts
• Why are there different types of production layouts?• Why are there different types of production layouts?There are different types of production
• 2 important factors to distinguish types of• 2 important factors to distinguish types of production
1. Production quantity (Q): the number of units of a1. Production quantity (Q): the number of units of a given product that the facility produces annually
– Low production (1‐100 units/year)– Medium production (100‐10,000 units/year)– High production (more than 10,000 units/year)
2 d ( ) d ff d d2. Product variety (P): different product designs or types that are produced (shape, size, style, function)
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Relationship btw Q & P
Relationship between production quantityRelationship between production quantity (Q) and product variety (P)
END 202 – Work analysis and design Facility Layout
Types of plant layouts
There are 4 basic types of plant layouts:
1 d ( h l ) l1. Product (straight‐line) layout
2. Process (functional) layout
3. Fixed‐position layout
4 Hybrid layouts – combination of the above4. Hybrid layouts combination of the above
(These layouts are commonly associated with production plants and therefore referred to as plant layouts)
END 202 – Work analysis and design Facility Layout
1. Product (straight‐line) layout
• High annual quantity, low product variety• Workstations and equipments are located along
th li f fl f th k itthe line of flow of the work units• The work units are typically moved along the
flow line by a powered conveyorflow line by a powered conveyor• A small amount of the total work is
accomplished at each workstationaccomplished at each workstation• It is widely used in the production lines and
assembly lines• Examples: ?
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2. Product (straight‐line) layout
Advantages• High degree of efficiency and proficiency• Specialized equipment and tooling can be developed to
reduce cycle timereduce cycle time• High production rates Disadvantages• Significant investment and high cost
(Risk: If actual demand is less than anticipated when the plant was built)p )
• Cannot be easily adapted to produce a different product• The equipments can become obsolete when the customer
demand changesdemand changes• Major revisions and investments may be required to
change over the plant for a new model
END 202 – Work analysis and design Facility Layout
2. Process (functional) layout
• Low and medium production quantities, medium and high product variety
• Equipments are arranged according to function
• There is no common work flow path through the plantthe plant
• Different parts or products are processed with different operation sequenceswith different operation sequences
• Examples: ?
END 202 – Work analysis and design Facility Layout
2. Process (functional) layout
AdvantagesAdvantages• Very flexible and versatile: deals with different
operations, different parts and productsp , p p• The equipments are of general purpose and can be
adapted for different products• Workforce: skilled workers who are well paidDisadvantages• E h t t i t t d f ti t• Each part type is transported from one operation to
the next: High material handling cost and high work‐in‐process inventoryp y
• Disadvantage of versatility: low efficiency because of the change of setups
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3. Fixed‐position layout
• Low product quantity, high product variety• The product remains in one location in the plant
during its whole fabrication (large and heavy products)
• The equipments and the workers are brought to the product
f f d• Component parts are often manufactured elsewhere and brought for final assembly
l l l h• Examples: Railway locomotives, heavy machinery, gas turbines, steam engines
END 202 – Work analysis and design Facility Layout
4. Hybrid layouts
2 basic types of hybrid layouts:
4.1 Cellular layout: tries to combine the best features of process and product layoutsfeatures of process and product layouts
4.2 Combinations of fixed position layouts and d lprocess or product layouts
END 202 – Work analysis and design Facility Layout
4.1 Cellular layouts
• Cellular manufacturing: workstations and• Cellular manufacturing: workstations and equipments are configured into cells consisting of several workstations
• Workstations are configured and tooled to make families of similar parts or products
• No drastic changes of setup• Group technology is used
(Similar parts or products are indentified and grouped together to take advantage of their similarities in design and production)g p )
• More efficient than process layout and more versatile than product layout.
END 202 – Work analysis and design Facility Layout
4.2 Combination of fixed position and process or product layoutor product layout
Large products are not built all at one location• ShipyardsShipyards
– Combination of fixed‐position and process layouts– Each module is produced and then welded to other p
modules at a single location in the welding department
Ai f• Aircraft– Combination of fixed‐position and product layouts
E B i l i W hi d i 747 777– Ex: Boeing plant in Washington producing 747 – 777 models
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Types of plant layouts
Types of plant layout used for different levels ofTypes of plant layout used for different levels of production quantity (Q) and product variety (P)
END 202 – Work analysis and design Facility Layout
Outline
• Types of production plant layoutsTypes of production plant layouts
• Other types of layoutsOther types of layouts
• Systematic layout planningSystematic layout planning
END 202 – Work analysis and design Facility Layout
Other types of layouts
There are additional layout types for operations other than productionoperations other than production
• Warehouse layouts
• Project layouts
• Service facility layoutsy y
• Office layouts
• …
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Warehouse layouts
• Warehouse is a facility for storing merchandise, commodities or other items,
• 4 main warehouse functions1 R i i1. Receiving
2. Storing
3. Order picking
4. Shipping
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Warehouse layouts
• Where to locate• Where to locate receiving and hi i f i ?shipping functions?
• Should the two• Should the two functions be
bi dcombined at one location or separated?
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Warehouse layouts
Advantages of centralizing at one locationg g• Sharing of personnel and material‐handling equipment• Sharing of docks and docking space (for example: if more
vehicles arrive for shipping than receiving at a time)• Facilitating cross‐docking: immediate transfer of received
materials to shipping itho t an storagematerials to shipping without any storageAdvantages of decentralizing (separating)• Reduced congestion in the dock areas• Reduced congestion in the dock areas• Reduced risk of confusing incoming loads with outgoing
materials• The layout can be designed to provide a flow‐through of
materials, from receiving to storage to shipping
END 202 – Work analysis and design Facility Layout
Project layouts
• Usually applies to construction projects
• The product of the project stays (theThe product of the project stays (the building) but the workers and the equipments moveequipments move
• The layout is temporary and depends on the project size and needs
• Similar to fixed‐position layoutp y– Basic difference?
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Service facility layouts
• Each type of service has its own layout• Each type of service has its own layout requirements
• Most are based on process layoutp y– Example: Department stores
• Usually, the goal is to minimize the distances t l d b k (i f ti ) d ltraveled by paperwork (information) and people (workers, customers, etc.)
• In retail merchandising: the goal is to maximize theIn retail merchandising: the goal is to maximize the exposure of customers to the items, maximum exhibitionA h i Th l d bi• Aesthetics: The general appearance and ambiance of a service facility must be pleasant
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Office layouts
• Similar to process layout: Personnel are typically grouped according to their functions or departmentsdepartments
• Each department has its own area• The closeness between different departments• The closeness between different departments
are important• The flow of work between departments shouldThe flow of work between departments should
be used to decide their locations• Noisemaking or dangerous departments are
located away
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Office layouts
New trend: open office conceptNew trend: open office concept• Consists of large open areas in which modular
furniture and partitions rather than permanent walls p pare used to designate and separate workstations
• Advantages– Lower construction costs– Easier supervision of employees
Fl ibilit f h i th l t– Flexibility for changes in the layout– Better control of heating, cooling, lighting– Improved communications among employeesImproved communications among employees
• Disadvantages?
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Outline
• Types of production plant layoutsTypes of production plant layouts
• Other types of layoutsOther types of layouts
• Systematic layout planningSystematic layout planning
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Plant layout designs
Levels of detail in plant layout designs
Site layout
Block layout
Workstationlayout
Detailed layout
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Systematic Layout Planning, SLP
• An approach to plant layout design developed by Richard Muther (1973)
• There are other approaches but this is the most widely used
• Most applicable to process layouts• Most appropriate for designing a new plant• The goal is to locate two areas with high
frequency and logical relationship close to one another using straightforward procedure
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Systematic Layout Planning, SLP
Steps (A. Freivalds):
1. Chart relationships
2. Establish space requirements
3. Activity relationships diagramy p g
4. Layout space relationships
5 Evaluate alternative arrangements5. Evaluate alternative arrangements
6. Select layout and install
Example: Plant layout of Dorben Consulting (pg 113)
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Systematic Layout Planning, SLP
Steps (M P Groover):Steps (M.P. Groover):1. Determine requirements and collect data2. Analyze material flowsy3. Define activity relationships and develop activity
relationship chart4 C t t ti it l ti hi di4. Construct activity relationship diagram5. Determine the space requirements6. Construct space relationship diagram6. Construct space relationship diagram7. Make adjustments, add allowances8. Develop block layout9. Develop detailed layout
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Systematic Layout Planning, SLP
Steps (END 308: Tompkins White Bozer and Tanchoco):Steps (END 308: Tompkins, White, Bozer and Tanchoco):1. Flow of materials2. Activity relationships3. Relationship diagram4. Space requirements5 S il bl5. Space available6. Space relationship diagram7. Modifying considerations7. Modifying considerations8. Practical limitations9. Develop layout alternatives10. Evaluation
To be discussed in END 308: Facilities Planning and Design
END 202 – Work analysis and design Facility Layout
g g
How to develop layout alternatives
• Exact methods (modeling the problem as a MIP and• Exact methods (modeling the problem as a MIP and solving exactly)
– usually limited– usually limited
• Heuristics, meta‐heuristics (genetic algorithms, simulated annealing ant colony etc )simulated annealing, ant colony, etc.)
• Commercially available optimization software –based on heuristics (CRAFT CORELAP ALDEP)based on heuristics (CRAFT, CORELAP, ALDEP)
• Virtual reality environment
Oth ft (F t PLAN F t FLOW• Other software (FactoryPLAN, FactoryFLOW, FactoryCAD)
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