Chapter 1
Overview of Manufacturing
Manufacturing Operations
CHAPTER CONTENTS
2.1 Manufacturing Industries and Products
2.2 Manufacturing Operations
2.2.1 Processing and Assembly Operations
2.2.2 Other Factory Operations
2.3 Production Facilities
2.3.1 Low Production
2.3.2 Medium Production
2.3.3 High Production
2.4 Product/Production Relationships
2.4.1 Production Quantity and Product Variety
2.4.2 Product and Part Complexity
2.4.3 Limitations and Capabilities of a Manufacturing Plant
Manufacturing can be defined as the application of physical and/or chemical processes
to alter the geometry, properties, and/or appearance of a given starting material to make
parts or products. Manufacturing also includes the joining of multiple parts to make as-
sembled products. The processes that accomplish manufacturing involve a combination
of machinery, tools, power, and manual labor, as depicted in Figure 2.1(a). Manufacturing
is almost always carried out as a sequence of unit operations.2 Each successive operation
brings the material closer to the desired final state.
1
The chapter introduction and Sections 2.1 and 2.2 are based on [2], Chapter 1.
2
A unit operation is a single step in the sequence of steps used to transform a starting material into a
final part or product.
1
,2 Chap. 1 / Manufacturing Operations
Machinery
Tools
Power Manufacturing
Labor process
Completed part
Starting or product
material Value added
Manufacturing
process
Scrap
and/or
waste Starting Material Completed
material in processing part or product
(a) (b)
Figure 2.1 Alternative definitions of manufacturing: (a)
as a technological process and (b) as an economic process.
From an economic viewpoint, manufacturing is concerned with the transforma-
tion of materials into items of greater value by means of one or more processing and/or
assembly operations, as depicted in Figure 2.1(b). The key point is that manufacturing
adds value to the material by changing its shape or properties or by combining it with
other materials that also have been altered. When iron ore is converted into steel, value
is added. When sand is transformed into glass, value is added. When petroleum is refined
into plastic, value is added. And when plastic is molded into the complex geometry of a
patio chair, it is made even more valuable.
This chapter provides a survey of manufacturing operations, beginning with the in-
dustries that are engaged in manufacturing and the types of products they produce. Then
the fabrication and assembly processes used in manufacturing are briefly described, as
well as the activities that support these processes, such as material handling and inspec-
tion. Next, several product parameters are introduced, such as production quantity and
product variety, and the influence that these parameters have on production operations
and facilities is examined.
The history of manufacturing includes both the development of manufacturing pro-
cesses, some of which date back thousands of years, and the evolution of the production
systems required to apply these processes (see Historical Note 2.1). The emphasis in this
book is on the systems.
Historical Note 2.1 History of Manufacturing
The history of manufacturing includes two related topics: (1) the discovery and invention of
materials and processes to make things and (2) the development of systems of production.
The materials and processes pre-date the systems by several millennia. Systems of production
refer to the ways of organizing people and equipment so that production can be performed
more efficiently. Some of the basic processes date as far back as the Neolithic period (circa
8000–3000 B.C.), when operations such as the following were developed: woodworking, form-
ing and firing of clay pottery, grinding and polishing of stone, spinning of fiber and weaving
of textiles, and dyeing of cloth. Metallurgy and metalworking also began during the Neolithic,
in Mesopotamia and other areas around the Mediterranean. It either spread to or developed
independently in regions of Europe and Asia. Gold was found by early humans in relatively
,Chap. 1 / Manufacturing Operations 3
pure form in nature; it could be hammered into shape. Copper was probably the first metal to
be extracted from ores, thus requiring smelting as a processing technique. Copper could not be
readily hammered because it strain-hardened; instead, it was shaped by casting. Other metals
used during this period were silver and tin. It was discovered that copper alloyed with tin pro-
duced a more workable metal than copper alone (casting and hammering could both be used).
This heralded the important period known as the Bronze Age (circa 3500–1500 B.C.).
Iron was also first smelted during the Bronze Age. Meteorites may have been one
source of the metal, but iron ore was also mined. The temperatures required to reduce iron
ore to metal are significantly higher than for copper, which made furnace operations more
difficult. Early blacksmiths learned that when certain irons (those containing small amounts
of carbon) were sufficiently heated and then quenched (thrust into water to cool), they be-
came very hard. This permitted the grinding of very sharp cutting edges on knives and weap-
ons, but it also made the metal brittle. Toughness could be increased by reheating at a lower
temperature, a process known as tempering. What has been described here is, of course, the
heat treatment of steel. The superior properties of steel caused it to succeed bronze in many
applications (weaponry, agriculture, and mechanical devices). The period of its use has sub-
sequently been named the Iron Age (starting around 1000 B.C.). It was not until much later,
well into the nineteenth century, that the demand for steel grew significantly and more mod-
ern steelmaking techniques were developed.
The early fabrication of implements and weapons was accomplished more as crafts
and trades than by manufacturing as it is known today. The ancient Romans had what
might be called factories to produce weapons, scrolls, pottery, glassware, and other prod-
ucts of the time, but the procedures were largely based on handicraft. It was not until the
Industrial Revolution (circa 1760–1830) that major changes began to affect the systems for
making things. This period marked the beginning of the change from an economy based
on agriculture and handicraft to one based on industry and manufacturing. The change
began in England, where a series of important machines was invented, and steam power
began to replace water, wind, and animal power. Initially, these advances gave British indus-
try significant advantages over other nations, but eventually the revolution spread to other
European countries and to the United States. The Industrial Revolution contributed to the
development of manufacturing in the following ways: (1) Watt’s steam engine, a new power-
generating technology; (2) development of machine tools, starting with John Wilkinson’s
boring machine around 1775, which was used to bore the cylinder on Watt’s steam engine;
(3) invention of the spinning jenny, power loom, and other machinery for the textile industry,
which permitted significant increases in productivity; and (4) the factory system, a new way of
organizing large numbers of production workers based on the division of labor.
Wilkinson’s boring machine is generally recognized as the beginning of machine tool
technology. It was powered by waterwheel. During the period 1775–1850, other machine
tools were developed for most of the conventional machining processes, such as boring, turn-
ing, drilling, milling, shaping, and planing. As steam power became more prevalent, it gradu-
ally became the preferred power source for most of these machine tools. It is of interest
to note that many of the individual processes pre-date the machine tools by centuries; for
example, drilling, sawing, and turning (of wood) date from ancient times.
Assembly methods were used in ancient cultures to make ships, weapons, tools, farm
implements, machinery, chariots and carts, furniture, and garments. The processes included
binding with twine and rope, riveting and nailing, and soldering. By around the time of Christ,
forge welding and adhesive bonding had been developed. Widespread use of screws, bolts,
and nuts—so common in today’s assembly—required the development of machine tools, in
particular, Maudsley’s screw cutting lathe (1800), which could accurately form the helical
threads. It was not until around 1900 that fusion welding processes started to be developed
as assembly techniques.
, 4 Chap. 1 / Manufacturing Operations
While England was leading the Industrial Revolution, an important concept related to
assembly technology was being introduced in the United States: interchangeable parts manu-
facture. Much credit for this concept is given to Eli Whitney (1765–1825), although its impor-
tance had been recognized by others [3]. In 1797, Whitney negotiated a contract to produce
10,000 muskets for the U.S. government. The traditional way of making guns at the time was
to custom-fabricate each part for a particular gun and then hand-fit the parts together by filing.
Each musket was therefore unique, and the time to make it was considerable. Whitney believed
that the components could be made accurately enough to permit parts assembly without fit-
ting. After several years of development in his Connecticut factory, he traveled to Washington
in 1801 to demonstrate the principle. Before government officials, including Thomas Jefferson,
he laid out components for 10 muskets and proceeded to select parts randomly to assemble
the guns. No special filing or fitting was required, and all of the guns worked perfectly. The
secret behind his achievement was the collection of special machines, fixtures, and gages that
he had developed in his factory. Interchangeable parts manufacture required many years of de-
velopment and refinement before becoming a practical reality, but it revolutionized methods
of manufacturing. It is a prerequisite for mass production of assembled products. Because its
origins were in the United States, interchangeable parts production came to be known as the
American System of manufacture.
The mid and late 1800s witnessed the expansion of railroads, steam-powered ships, and
other machines that created a growing need for iron and steel. New methods for producing
steel were developed to meet this demand. Also during this period, several consumer products
were developed, including the sewing machine, bicycle, and automobile. To meet the mass de-
mand for these products, more efficient production methods were required. Some historians
identify developments during this period as the Second Industrial Revolution, characterized in
terms of its effects on production systems by the following: (1) mass production, (2) assembly
lines, (3) the scientific management movement, and (4) electrification of factories.
Mass production was primarily an American phenomenon. Its motivation was the mass
market that existed in the United States. Population in the United States in 1900 was 76 million
and growing. By 1920, it exceeded 106 million. Such a large population, larger than any western
European country, created a demand for large numbers of products. Mass production provided
those products. Certainly one of the important technologies of mass production was the assem-
bly line, introduced by Henry Ford (1863–1947) in 1913 at his Highland Park plant (Historical
Note 15.1). The assembly line made mass production of complex consumer products possible.
Use of assembly-line methods permitted Ford to sell a Model T automobile for less than $500 in
1916, thus making ownership of cars feasible for a large segment of the American population.
The scientific management movement started in the late 1800s in the United States
in response to the need to plan and control the activities of growing numbers of produc-
tion workers. The movement was led by Frederick W. Taylor (1856–1915), Frank Gilbreath
(1868–1924) and his wife Lilian (1878–1972), and others. Scientific management included (1)
motion study, aimed at finding the best method to perform a given task; (2) time study, to
establish work standards for a job; (3) extensive use of standards in industry; (4) the piece rate
system and similar labor incentive plans; and (5) use of data collection, record keeping, and
cost accounting in factory operations.
In 1881, electrification began with the first electric power generating station being built in
New York City, and soon electric motors were being used as the power source to operate fac-
tory machinery. This was a far more convenient power delivery system than the steam engine,
which required overhead belts to mechanically distribute power to the machines. By 1920, elec-
tricity had overtaken steam as the principal power source in U.S. factories. Electrification also
motivated many new inventions that have affected manufacturing operations and production
systems. The twentieth century was a time of more technological advances than all previous
centuries combined. Many of these developments have resulted in the automation of manu-
facturing. Historical notes on some of these advances in automation are included in this book.
Overview of Manufacturing
Manufacturing Operations
CHAPTER CONTENTS
2.1 Manufacturing Industries and Products
2.2 Manufacturing Operations
2.2.1 Processing and Assembly Operations
2.2.2 Other Factory Operations
2.3 Production Facilities
2.3.1 Low Production
2.3.2 Medium Production
2.3.3 High Production
2.4 Product/Production Relationships
2.4.1 Production Quantity and Product Variety
2.4.2 Product and Part Complexity
2.4.3 Limitations and Capabilities of a Manufacturing Plant
Manufacturing can be defined as the application of physical and/or chemical processes
to alter the geometry, properties, and/or appearance of a given starting material to make
parts or products. Manufacturing also includes the joining of multiple parts to make as-
sembled products. The processes that accomplish manufacturing involve a combination
of machinery, tools, power, and manual labor, as depicted in Figure 2.1(a). Manufacturing
is almost always carried out as a sequence of unit operations.2 Each successive operation
brings the material closer to the desired final state.
1
The chapter introduction and Sections 2.1 and 2.2 are based on [2], Chapter 1.
2
A unit operation is a single step in the sequence of steps used to transform a starting material into a
final part or product.
1
,2 Chap. 1 / Manufacturing Operations
Machinery
Tools
Power Manufacturing
Labor process
Completed part
Starting or product
material Value added
Manufacturing
process
Scrap
and/or
waste Starting Material Completed
material in processing part or product
(a) (b)
Figure 2.1 Alternative definitions of manufacturing: (a)
as a technological process and (b) as an economic process.
From an economic viewpoint, manufacturing is concerned with the transforma-
tion of materials into items of greater value by means of one or more processing and/or
assembly operations, as depicted in Figure 2.1(b). The key point is that manufacturing
adds value to the material by changing its shape or properties or by combining it with
other materials that also have been altered. When iron ore is converted into steel, value
is added. When sand is transformed into glass, value is added. When petroleum is refined
into plastic, value is added. And when plastic is molded into the complex geometry of a
patio chair, it is made even more valuable.
This chapter provides a survey of manufacturing operations, beginning with the in-
dustries that are engaged in manufacturing and the types of products they produce. Then
the fabrication and assembly processes used in manufacturing are briefly described, as
well as the activities that support these processes, such as material handling and inspec-
tion. Next, several product parameters are introduced, such as production quantity and
product variety, and the influence that these parameters have on production operations
and facilities is examined.
The history of manufacturing includes both the development of manufacturing pro-
cesses, some of which date back thousands of years, and the evolution of the production
systems required to apply these processes (see Historical Note 2.1). The emphasis in this
book is on the systems.
Historical Note 2.1 History of Manufacturing
The history of manufacturing includes two related topics: (1) the discovery and invention of
materials and processes to make things and (2) the development of systems of production.
The materials and processes pre-date the systems by several millennia. Systems of production
refer to the ways of organizing people and equipment so that production can be performed
more efficiently. Some of the basic processes date as far back as the Neolithic period (circa
8000–3000 B.C.), when operations such as the following were developed: woodworking, form-
ing and firing of clay pottery, grinding and polishing of stone, spinning of fiber and weaving
of textiles, and dyeing of cloth. Metallurgy and metalworking also began during the Neolithic,
in Mesopotamia and other areas around the Mediterranean. It either spread to or developed
independently in regions of Europe and Asia. Gold was found by early humans in relatively
,Chap. 1 / Manufacturing Operations 3
pure form in nature; it could be hammered into shape. Copper was probably the first metal to
be extracted from ores, thus requiring smelting as a processing technique. Copper could not be
readily hammered because it strain-hardened; instead, it was shaped by casting. Other metals
used during this period were silver and tin. It was discovered that copper alloyed with tin pro-
duced a more workable metal than copper alone (casting and hammering could both be used).
This heralded the important period known as the Bronze Age (circa 3500–1500 B.C.).
Iron was also first smelted during the Bronze Age. Meteorites may have been one
source of the metal, but iron ore was also mined. The temperatures required to reduce iron
ore to metal are significantly higher than for copper, which made furnace operations more
difficult. Early blacksmiths learned that when certain irons (those containing small amounts
of carbon) were sufficiently heated and then quenched (thrust into water to cool), they be-
came very hard. This permitted the grinding of very sharp cutting edges on knives and weap-
ons, but it also made the metal brittle. Toughness could be increased by reheating at a lower
temperature, a process known as tempering. What has been described here is, of course, the
heat treatment of steel. The superior properties of steel caused it to succeed bronze in many
applications (weaponry, agriculture, and mechanical devices). The period of its use has sub-
sequently been named the Iron Age (starting around 1000 B.C.). It was not until much later,
well into the nineteenth century, that the demand for steel grew significantly and more mod-
ern steelmaking techniques were developed.
The early fabrication of implements and weapons was accomplished more as crafts
and trades than by manufacturing as it is known today. The ancient Romans had what
might be called factories to produce weapons, scrolls, pottery, glassware, and other prod-
ucts of the time, but the procedures were largely based on handicraft. It was not until the
Industrial Revolution (circa 1760–1830) that major changes began to affect the systems for
making things. This period marked the beginning of the change from an economy based
on agriculture and handicraft to one based on industry and manufacturing. The change
began in England, where a series of important machines was invented, and steam power
began to replace water, wind, and animal power. Initially, these advances gave British indus-
try significant advantages over other nations, but eventually the revolution spread to other
European countries and to the United States. The Industrial Revolution contributed to the
development of manufacturing in the following ways: (1) Watt’s steam engine, a new power-
generating technology; (2) development of machine tools, starting with John Wilkinson’s
boring machine around 1775, which was used to bore the cylinder on Watt’s steam engine;
(3) invention of the spinning jenny, power loom, and other machinery for the textile industry,
which permitted significant increases in productivity; and (4) the factory system, a new way of
organizing large numbers of production workers based on the division of labor.
Wilkinson’s boring machine is generally recognized as the beginning of machine tool
technology. It was powered by waterwheel. During the period 1775–1850, other machine
tools were developed for most of the conventional machining processes, such as boring, turn-
ing, drilling, milling, shaping, and planing. As steam power became more prevalent, it gradu-
ally became the preferred power source for most of these machine tools. It is of interest
to note that many of the individual processes pre-date the machine tools by centuries; for
example, drilling, sawing, and turning (of wood) date from ancient times.
Assembly methods were used in ancient cultures to make ships, weapons, tools, farm
implements, machinery, chariots and carts, furniture, and garments. The processes included
binding with twine and rope, riveting and nailing, and soldering. By around the time of Christ,
forge welding and adhesive bonding had been developed. Widespread use of screws, bolts,
and nuts—so common in today’s assembly—required the development of machine tools, in
particular, Maudsley’s screw cutting lathe (1800), which could accurately form the helical
threads. It was not until around 1900 that fusion welding processes started to be developed
as assembly techniques.
, 4 Chap. 1 / Manufacturing Operations
While England was leading the Industrial Revolution, an important concept related to
assembly technology was being introduced in the United States: interchangeable parts manu-
facture. Much credit for this concept is given to Eli Whitney (1765–1825), although its impor-
tance had been recognized by others [3]. In 1797, Whitney negotiated a contract to produce
10,000 muskets for the U.S. government. The traditional way of making guns at the time was
to custom-fabricate each part for a particular gun and then hand-fit the parts together by filing.
Each musket was therefore unique, and the time to make it was considerable. Whitney believed
that the components could be made accurately enough to permit parts assembly without fit-
ting. After several years of development in his Connecticut factory, he traveled to Washington
in 1801 to demonstrate the principle. Before government officials, including Thomas Jefferson,
he laid out components for 10 muskets and proceeded to select parts randomly to assemble
the guns. No special filing or fitting was required, and all of the guns worked perfectly. The
secret behind his achievement was the collection of special machines, fixtures, and gages that
he had developed in his factory. Interchangeable parts manufacture required many years of de-
velopment and refinement before becoming a practical reality, but it revolutionized methods
of manufacturing. It is a prerequisite for mass production of assembled products. Because its
origins were in the United States, interchangeable parts production came to be known as the
American System of manufacture.
The mid and late 1800s witnessed the expansion of railroads, steam-powered ships, and
other machines that created a growing need for iron and steel. New methods for producing
steel were developed to meet this demand. Also during this period, several consumer products
were developed, including the sewing machine, bicycle, and automobile. To meet the mass de-
mand for these products, more efficient production methods were required. Some historians
identify developments during this period as the Second Industrial Revolution, characterized in
terms of its effects on production systems by the following: (1) mass production, (2) assembly
lines, (3) the scientific management movement, and (4) electrification of factories.
Mass production was primarily an American phenomenon. Its motivation was the mass
market that existed in the United States. Population in the United States in 1900 was 76 million
and growing. By 1920, it exceeded 106 million. Such a large population, larger than any western
European country, created a demand for large numbers of products. Mass production provided
those products. Certainly one of the important technologies of mass production was the assem-
bly line, introduced by Henry Ford (1863–1947) in 1913 at his Highland Park plant (Historical
Note 15.1). The assembly line made mass production of complex consumer products possible.
Use of assembly-line methods permitted Ford to sell a Model T automobile for less than $500 in
1916, thus making ownership of cars feasible for a large segment of the American population.
The scientific management movement started in the late 1800s in the United States
in response to the need to plan and control the activities of growing numbers of produc-
tion workers. The movement was led by Frederick W. Taylor (1856–1915), Frank Gilbreath
(1868–1924) and his wife Lilian (1878–1972), and others. Scientific management included (1)
motion study, aimed at finding the best method to perform a given task; (2) time study, to
establish work standards for a job; (3) extensive use of standards in industry; (4) the piece rate
system and similar labor incentive plans; and (5) use of data collection, record keeping, and
cost accounting in factory operations.
In 1881, electrification began with the first electric power generating station being built in
New York City, and soon electric motors were being used as the power source to operate fac-
tory machinery. This was a far more convenient power delivery system than the steam engine,
which required overhead belts to mechanically distribute power to the machines. By 1920, elec-
tricity had overtaken steam as the principal power source in U.S. factories. Electrification also
motivated many new inventions that have affected manufacturing operations and production
systems. The twentieth century was a time of more technological advances than all previous
centuries combined. Many of these developments have resulted in the automation of manu-
facturing. Historical notes on some of these advances in automation are included in this book.
