Introduction to Plant Layout

Plant layout and Material Handling

Introduction – Classification – Different Layouts – Layout Design

Procedures – Overview

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Definitions

• Facilities layout describes the arrangement of equipment, storage areas, and work areas, usually within the confines of a physical structure, such as a retail store, an office, a warehouse, or a manufacturing facility.

• Factors that influence layout– Volume, weight of items to be produced.– Nature of the service to be provided.– Cost of the building to house the operation.– The product mix that must have a facility.– The fragility of the product or component

What is a “Layout?”

• The physical arrangement of economic activity centers within a facility.– A “center” can be anything that consumes space.

• The Layout decisions are:– What centers?– How much space and capacity?– Configuration?– Where to locate them?

Why?

Arrangement of areas within a facility to:

• Minimize material-handling costs• Utilize space efficiently• Utilize labor efficiently• Eliminate bottlenecks• Facilitate communication and

interaction• Reduce manufacturing cycle

time• Reduce customer service time• Eliminate wasted or redundant

movement• Increase capacity

• Facilitate entry, exit, and placement of material, products, and people

• Incorporate safety and security measures

• Promote product and service quality

• Encourage proper maintenance activities

• Provide a visual control of activities• Provide flexibility to adapt to

changing conditions

Three Basic Types of Layout

1. Product Layouts2. Process Layouts3. Fixed-position Layouts

Types of Layout

Fixed PositionLine-Flow (Product)Flexible-Flow (Process)HybridRetailWarehouseOffice

Directly concerned with layout of the transformation process.

Not directly concerned with the transformation process.

Product Layouts

• Product layouts employ standardized processing operations to achieve smooth, rapid, and high volume flow.

Process Layout

• Process layouts group similar equipment together according to the process they perform.

PRINTING ASSEMBLY PACKING

CUTTING

RECEIVING

SHIPPING

Process Layout• Grouping together of machines and/or workers doing

similar tasks.• Applicable to both manufacturing and non manufacturing

operations.• Advantages

– Flexibility: equipment and personnel can be used where they are needed.

– Smaller investment in equipment: duplication is not necessary unless volume is large.

– Expertise: supervisors for each department become highly. knowledgeable about their functions

– Diversity of tasks: changing work assignments make work more satisfying for people who prefer variety.

Process Layout

• Disadvantages– Lack of process efficiency: backtracking and long movements may

occur in the handling of materials.– Lack of efficiency in timing: workers must wait between tasks.– Complication of production planning and control.– Cost: workers must have broad skills and must be paid higher

wages than assembly line workers.– Lowered productivity: because each job is different it requires

different setups and operator training.

Fixed-position Layouts

• Fixed-position layouts place the products stationary, and workers, materials, and equipment are moved to the products.

EMPLOYEETEAM 1

EMPLOYEETEAM 3

EMPLOYEETEAM 2

MACHINEGROUP 1

MACHINEGROUP 2

STORAGE# 2

STORAGE# 3

EMPLOYEETEAM 4

MACHINEGROUP 3

MACHINEGROUP 4

STORAGE# 1

STORAGE# 4

Fixed Position Layout• Manufacturing and non-manufacturing operations of bulky

or fragile products, e.g., ships and planes.• Move machines and/or workers to the site; products

normally remains in one location for its entire manufacturing period.

• Advantages of fixed position layout– Reduces movement of work items; minimizes damage or cost of

moving. – More continuity of the assigned work force (since the item does

not go from one department to another). This reduces the problems of re-planning and instructing people each time a new type of activity is to begin.

Fixed Position Layout

• Disadvantages of fixed position layout– Since the same workers are involved in more operations, skilled

and versatile workers are required. The necessary combination of skills may be difficult to find and high pay levels may be necessary.

– Movement of people and equipment to and from the work site may be expensive.

– Equipment utilization may be low because the equipment may be left at a location where it will be needed again in a few days rather than moved to another location where it would be productive.

Group Technology Layout

• Definition of Group Technology“Group technology is the technique of identifying and bringing together related or similar parts in a production process in order to utilize the inherent economy of flow production methods.”

Group Technology Layout• Group Technology layout is also called manufacturing cell

layout. • Example:

– A plant producing 10,000 part numbers may be able to group the parts into 50 or 60 families. Each family would possess similar design and manufacturing characteristics.

– Hence, the processing of each member of a given family would be similar, and this results in manufacturing efficiencies in the form of:

• Reduced set-up, • Lower in-process inventories, • Better scheduling, • Improved tool control,• Standard process plan.

Hybrid Layout

Hybrid layouts modify and/or integrate certain characteristics of the three basic layout types.

1. Cellular layouts group different machines into cells that process parts with similar shapes or processing requirements.

2. Flexible Manufacturing Systems (FMS) integration of several flexible cells making up a cellular layout, which is capable of producing a large variety of products

Flow-Line Layout• Applicable to both manufacturing and non manufacturing

operations.• Arrange machines and/or workers in accordance with the

sequence of operations for a given product or service.• Advantages of flow-line layout

– Reduces materials handling.– Accommodates small amounts of work in process.– Reduces transit times.– Simplifies production planning and control systems.– Simplifies tasks, enabling unskilled workers to learn task quickly.

Flow-Line Layout• Disadvantages of flow-line layout

– Lack of process flexibility.– Lack of flexibility in timing: the product can not flow through the

line faster than the slowest task can be accomplished unless that task is performed at several stations.

– Large investments: special-purpose equipment and duplication is required to offset lack of flexibility in timing.

– Dependence of the whole on each part: a breakdown of one machine or absence of enough operators to staff all work stations may stop the entire line.

– Worker fatigue: workers may become bored by the endless repetition of simple tasks.

Classification

Process Layout

L

L

L

L

L

L

L

L

L

LM

M

M

M

D

D

D

D

D

D

D

D

G

G

G

G

G

G

A A AReceiving andShipping Assembly

Painting Department

Lathe DepartmentMilling Department Drilling Department

Grinding Department

P

P

Product Layout

In

Out

Factors To Be Considered For Selection Of Region

• Primary Factors– Market nearness– Raw-material availability– Labor availability– Transport availability– Power and fuel supply– Existence of similar firms

• Secondary Factors– Climate suitability– Character of the

inhabiting community– State and local taxation-

rates– Expansion facility– Decentralization

suitability

Category FactorsProcess Input Raw Material, Personnel, Transportation of Raw Material,

work force availability, Availability of water and power, Road Transport, Railways etc.

Process Output Market nearnessProcess Characteristics Environmental factors such as pollution, noise etc., weather

(e.g. knitting industry), level of humidity and season, rainfall.

Personal Preference Preference of executives and entrepreneurGovernment Policy Tax exemptions, legal requirements, Incentives, Availability of

Loan/Land etc.Local Conditions Community culture and attitude. Past history of industry

located in the area, incidents of labour unrest in the area, Political Interference etc.

Cost Factors Cost of land, cost of transportation, Wages of unskilled labour

Competition Location of other industries in the area, Market forces for competition etc.

Intangible Factors International considerations, Possibility for expansion and growth, School, Churches, Medical, Recreation Facilities etc.

Facility Location Study

Comparative study of Rural and Urban Sites

Factors Urban/City site

Sub-Urban

Rural/Country

site

Availability of land Less Moderate Plenty

Cost of land High Moderate Low

Connected by rail/road etc. Well Moderate Poor

Availability of labour Less Moderate More

Wages of labour More Moderate Less

Comparative study of Rural and Urban Sites

Factors Urban/City site

Sub-Urban

Rural/Country

siteCommunication network like internet, facsimile, telephone, e-mail etc.

Very good Moderate Poor

Power and water availability Good Moderate Poor

Supporting industries and ancillaries units Near by Moderate Far

Quality of life, such as recreation, school, hospital etc.

Very good Moderate Poor

Market and consumer Near by Moderate To be built

Building for site May be rented or build

Rented Poor

Comparative study of Rural and Urban Sites

Factors Urban/City site

Sub-Urban

Rural/Country

siteAvailability and retaining potential for professional like manger and engineers

Better Not available outside

Training of workers and foreman In local institutions

May or may not

Less

Security Better Moderate Less

Expansion of site Difficult Moderate Easy

Taxes More Moderate Less

Government support Less More

Union problem and industrial relation Poor Better

Comparative study of Rural and Urban Sites

Factors Urban/City site

Sub-Urban

Rural/Country site

Pollution and environmental constraints

More Less

Waste disposal Difficult Easy

Location of sub contractors, retailers, etc.

Nearby Far

Incentives from financial institutions like banks, IDBI, IFCI etc.

Less More

A Good Layout ...

• Reduces bottlenecks in moving people or material.• Minimizes materials-handling costs.• Reduces hazards to personnel.• Utilizes labor efficiently.• Increases morale.• Utilizes available space effectively and efficiently.• Provides flexibility.• Provides ease of supervision.• Facilitates coordination and face-to-face

communication where appropriate.

Computer Packages (Unit 2)• Heuristic, improvement algorithms.• CRAFT (Computerized Relative Allocation of Facilities

Techniques) is the best known of the heuristics approaches; attempts to minimize materials-handling cost by calculating cost, pair-wise interchanging departments, calculating more costs until a good solution is obtained.

• ALDEP (Automated Layout Design Program) and CORELAP (Computerized Relationship Layout Planning) attempt to maximize a nearness rating within the facility dimension constraints.

• PREP (Plant Re-layout and Evaluation Package) analyzes multilevel structures and is based on actual footage traveled by materials-handling equipment.