Modern Methods of
Manufacturing
Course Content
Elements of Manufacturing: batch, mass, cellular and flexible. Concepts of computer integrated manufacturing system.
Use of robots in manufacturing and assembly.
Material Removal Processes: Needs and roles of newer processes. Evaluation of processes and their relation to
productivity. Recent advances in metal cutting, joining, coating; Process based on concentration of energy in the forms of beam
etc.
Metal forming Processes: sophisticated control of metallurgical parameters, Processing environment, deformation rate etc.;
Processes based on chemical interactions, solid phase bonding and joining operations. Micro & Nano fabrication technologies.
Advance Manufacturing Processes: Layered manufacturing, classification and description of layered manufacturing
processes. Applications of layered manufacturing. Non-conventional advanced manufacturing processes. Hybrid manufacturing
processes and their applications.
References
Text Books:
 Kalpakjian and Schmid, Manufacturing processes for engineering materials (5th
Edition)-Pearson India, 2014
Reference Books:
 Mikell P. Groover, Fundamentals of Modern Manufacturing: Materials,
Processes, and Systems
 Degarmo, Black & Kohser, Materials and Processes in Manufacturing
What is Manufacturing???
Manufacturing - Technical:
Manufacturing - Economical:
• Application of physical and chemical processes
to
alter
the
geometry,
properties,
and/or
appearance of a given starting material to make
parts or products
• Sequence of operations
• E.g. piercing on steel plate
• Transformation of materials into items of
greater value by means of one or more
processing and/or assembly operations.
• M/fing adds value to the product
• E.g. Refining crude oil into petroleum
product.
Stages in Manufacturing
Factors responsible:
Globalization
International
outsourcing
Quality expectations
Operational efficiency
Hand crafted tools
Power driven tools
Production System
Definition: Collection of people, equipment and procedures organized to perform
the manufacturing operations of a company
Components of Production system:
1. Facilities: the factory and equipment in the facility
and the way the facility is organized (plant layout).
2. Manufacturing support system: set of procedure used
to manage production, technical, logistic issues in a company
A combination of group of workers and machines termed as
Production line.
Schematic representation of a
production system
Production system facilities
Facilities include the factory, production machines and tooling, material handling
equipment, Inspection equipment and computer systems that control the manufacturing
operations.
 Plant layout: the way the equipment is physically arranged in the factory
 Manufacturing systems: logical groupings of equipment and workers in the factory
- Production line
- Stand alone workstation
To design a facility, we need to know
Flow
How do things move around?
(lot size, unit load size, MH requirement, building configurations)
Space
How much room do we need?
(storage system, layout arrangement, equipment size)
Activity relationships
close together or far apart?
(Material flow, personnel flow, environmental factors)
Type of production system affects flow, space and
relationships
High efficiency
Product volume
High
Product
layout
Group
technology
Medium
Low
Fixed
location
layout
Low
High flexibility
Process
layout
Medium
Product Variety
High
Manufacturing system- Factors Involved
Manufacturing
system:
collection
of
integrated equipment and human resources,
that performs one or more processing and/or
assembly operations on a starting raw material,
part, or set of parts
The
integrated
equipment
consist
of
production machines, material handling and
positioning devices and computer systems
Manufacturing system accomplish the value
added work on the part or product.
Classification of manufacturing system
Manual work system (filing work)
Worker machine system (turning operation on lathe)
Automated system (turning by CNC)
Manufacturing support system
Cycle of information – processing activities that
consists of four functions:
1. Business functions – sales and marketing,
order entry, cost accounting, customer billing
2. Product design – research and development,
design engineering and prototype shop
3. Manufacturing planning – process planning,
production planning, MRP, capacity planning
4. Manufacturing control – shop floor control,
inventory control, quality control
Role of humans in Manufacturing system
• Decision making
• Learning
• Evaluating
• Managing
• Equipment maintenance
• Upgradation
• Plant management
Classification of production system
• Type of production – Job shop production, Batch production, Mass
production
• Size of the plant – Large size plant (e.g. Oil refinery), Medium size plant,
Small size plant (e.g. Printing press)
• Type of product - simple to complex
• Physical flow of material – Automated flow, Semi-automated flow and
Manual flow
• Nature of order/demand pattern – Stable demand, Unstable demand
• Variety of jobs – More variety (e.g. Automobiles/electronic goods), One
variety (e.g. Oil refinery)
Types of Manufacturing
Types of Manufacturing
Factors
Volume of
production
Variety
Job
low
Mass
High
Continuous
High
Medium
Intermittent
Low
Regular
demand
Manpower
Machines
Highly skilled Skilled
Flexible
Flexible
Less skilled
Rigid
Single product
Higher than
actual
production
Less skilled
Automated
Investment
Production
planning
High
complex
High
Complex
Low
Easy
high
Routine
Medicines,
bakery,
seasonal item
Car, TV,
Mobiles etc.
Cement,
Petrol, diesel
etc.
Demand
High
Customer
dependent
Batch
Medium
Aircraft,
Applications Shipbuilding,
oil refinery
Types of machine layout
• Fixed position layout (Job production)
• Workers, materials and machines moved
• Process layout (Job or batch production)
• Varied processing requirements
• Product layout (Mass production)
• follows standard processing operations
• High volume flow
Product layout
Fixed position layout
Importance of Automation
Automation: technology by which a process or procedure is performed without
human assistance
• To increase labor productivity
• To reduce labor cost
• To mitigate the effects of labor shortage
• To improve worker safety
• To improve product quality
• To reduce manufacturing lead time
• To avoid high cost of not automating
Types of Automation
Fixed Automation
- Sequence of processing operations is
fixed by the equipment configuration.
- Sequence of simple operations.
- Integration and coordination of many
operations in one equipment.
Features
1. High initial cost.
2. Custom engineered equipment.
3. High production rates.
4. Inflexibility.
Programmable Automation
Flexible Automation
• Capable to change the sequence of operation
• System is capable of changing over from one
through reprogramming to accommodate
job to next with little lost time between jobs
different product configurations
• High investment in programmable equipment
• Low production rate than fixed automation
• Suitable for batch production
• Flexibility to deal with variations and changes
in product configuration
• E.g. NC machine tool, Industrial robots, PLC
• High investment for custom-engineered
system
• Continuous production of variable mixes of
products
• Medium production rates
• Flexibility to deal with soft product variety
• E.g. FMS
What is System??
Eg: human body, educational institutions, business organizations.
Components of a system: The input, processing, output and control of a system are called
the components of a system.
Control: There are two types of control, namely Proactive Control and Reactive Control.
There are three types of feedback mechanisms such as feed forward control, feedback control
and concurrent control.
Control systems
Feedforward control system
Feedback control system
Characteristics of feedforward control system
Characteristics of feedback control system
- Corrective action be taken in well advance, based on
- Corrective action taken as per the output signal
identification of disturbing variables
- Knowledge of controlled variables influence on
possible disturbances.
- Accurate process model required
- Little knowledge of process variables required.
- Preferred for manufacturing of highly accurate parts
- System sensitivity to plant uncertainties will be less
Flow line production/In process production
• Machines are arranged as per sequence of manufacturing operations
• Variety is less and volume/demand is high, hence product layout is
followed
• Suitable for mass production
• Breakdown in any machine affect
complete line of operation
Cellular manufacturing/Group technology
“Similar things are done similarly”
Things can be:
• Product design
• Process planning
• Fabrication and assembly
• Production control
• Administrative functions
Dissimilar machines/facilities are grouped called “cells” to process parts with similarity.
Dividing machines/dividing parts based on their similarities into families
- Machine cells
- Part families
GT is suited, where batch production and process layout is used
Functional layout/Process layout
A
Assembly
13
11
1
A
15
14
12
3
2
B
C
B
4
5
6
7
Raw material
10
8
9
C
Cellular layout
Assembly
A
4
11
6
14
1
A
B
Raw material
C
12
13
15
7
2
8
9
B
10
C
Benefits of cellular manufacturing
• Reduced material handling and change over time
• Reduced work-in-process inventory
• Better use of human resources:
• Self-managed team, in most cases more satisfied with the work that they do
• Flexible resource. Workers in each cell are multifunctional and can be
assigned to different routes within a cell or between cells as demand volume
changes.
• Easier to control
• Easier to automate
Issues in cellular design
• Cell formation - Grouping machines into machine cell and parts into part family
by parts production process
• Cell Scheduling and sequencing – scheduling and sequencing of jobs within cell
• Cell performance evaluation • Nagare cells – single operator handles multiple machines
Group Technology
• Group Technology (GT) is a method of manufacturing parts by the classification of these
parts into groups and subsequently applying the similar technological operations to each
group.
• Groupings not according to physical appearance
• Grouping criterion?
- Design characteristics – size, shape and function
- Process characteristics – type and sequence of opn
Techniques used for defining part families
• Visual inspection
• Part classification and coding – size, shape and material
• Production flow analysis (PFA) – uses route sheets to form a family
Characteristics of cellular layout
• More than one machine per operator
• Low WIP
• Faster response to quality problems
• Shorter throughput time
• Easier scheduling and control
U-shape production layout
Types of cellular manufacturing layout
• Inter cell layout – layout of cells within the factory
• Intra cell layout – layout of machines within each cell
Looped layout
U shape layout
Elements of CIM
• Computerized integration of all aspects of design, planning, manufacturing,
distribution and management.
• Includes all engineering functions of CAD/CAM and also business functions.
• Product and process design, production planning and control and production
processes replaced by CAD/CAM, CAPP and automated material handling
system and computerized business systems.
• Completely automated factory with no human interface and factory of the
future.
• To transform ideas into a high quality products in the minimum cost and
minimum time.
• CIM technologies tied together using a network and integrated databases.
CIM Wheel
By CASA/SME in 1980s
Computer-Integrated Manufacturing (CIM)
• Term Coined by James Harrington in 1973
• CIM is the integration of total manufacturing enterprise through the use of
integrated system and data communication mixed with new managerial
philosophies which results in the improvement of personnel or organizational
efficiencies
• CIM depends on usage of a large-scale integrated communications system
• Requires extensive database containing technical and business information
Evolution of CIM
• 1909 – Ford’s concept of production line
• 1923 – Automatic transfer machine in Morris engine factory
• 1952 – Generation of punched paper tape
• 1954 – first NC milling machine in Parson corporation of USA by MIT
• 1959 – 1st application of computer control at Texaco Refinery of USA
• 1970s – CAD, CAM, GT, Flexible automation & DNC developed.
• 1980s – FMS & CIM became popular
Factors Lead to CIM
• Development of NC, CNC & DNC.
• Advent & cost effective computers.
• Manufacturing challenges
 Global competition
 High labor cost
 Demand for quality products
 Flexibility to meet orders
 Lower product cost
Computer Aided Design
•
Computer-aided design (CAD) uses the computers to create design
drawings and geometric models of products and components.
Elements of CAD System
1. Geometric modelling
 Study of methods and algorithms for the mathematical description of shapes
2. Design analysis and optimization
 Design is subjected to an engineering analysis
3. Design review and evaluation
 Review and evaluation to check for any interference among various components
3. Documentation
 Detailed, working drawings are developed and printed
Computer Aided Manufacturing (CAM)
•
CAM involves the use of computer technology to assist in all phases of
manufacturing.
•
CAD/CAM systems allows information transfer from design to planning
stage.
•
Advantages of CAD/CAM are:
1. standardizing product development
2. reducing the effort of designing, evaluation and prototype work
Computer Aided Process Planning (CAPP)
•
Process planning involves selecting methods of the sequence of
operations, processing time and methods of assembly.
•
Computer-aided process planning (CAPP) view total operation as an
integrated system, so that individual operations are coordinated with each
other.
Elements of CAPP systems
•
Two types of CAPP systems:
1. Variant System
•
Computer files contain a standard process plan for a particular part to be
manufactured.
2. Generative System
•
Process plan is automatically generated on the basis of the same logical
procedures.
Advantages of CAPP systems
1. Standardization of process plans improves the productivity.
2. Process plans can be prepared.
3. Process plans can be modified.
4. Routing sheets can be prepared.
5. Other functions can be incorporated.
Flexible Manufacturing System
•
In FMS all elements of manufacturing are integrated into an automated system
•
Different computer instructions can be downloaded for each successive part that
passes through a workstation
•
Can handle a variety of part configurations and produce in any order
Elements of FMS
1. Workstations
2. Automated handling and transport of materials and parts
3. Control systems
•
System capable of transporting raw materials, blanks, and parts in various stages
of completion anytime.
The animation below shows how a computer control room directs all operations
inside the factory
How CIM Functions!
• Evaluating and developing different product strategies
• Market analysis and forecasting.
• Analyzing product / market characteristics & generates concept of possible
manufacturing system (FMS & FMC).
• Designing and Analyzing components for machining, inspection, assembly and
other processes.
• Evaluating and determining batch sizes, manufacturing capacity, scheduling and
control strategies.
• Analysis and feedback for manufacturing processes.
• Analysis of system disturbances and economic factors.
Objectives of CIM
• More productive and efficient processes.
• Increase product reliability.
• Decrease cost of production and maintenance
• Reduce number of hazardous jobs.
• Increase involvement of educated and able humans in manufacturing
and design.
Capabilities of CIM
• Responsiveness to rapid changes in market demand and product modification
• Better use of materials, machinery and personnel
• Better control of production and management of the total manufacturing
operation
• Manufacturing high quality product at low cost