built one at a time or in very small lots. Parts were made and fitted
to the particular machine to which they belonged; and while the same
general form and dimensions were practically maintained, there was no
attempt made to render the several parts so exact as to fit upon any
other machine than the one for which they were intended. Systems of
gauges had not been developed, and the planer was yet a comparatively
new tool; much work was still done by hand, the hammer, the cold
chisel, and the file being the chief reliance of a large majority of
machinists. This was the state of the machine shop and its methods
nearly up to the year 1800.
=Interchangeable Manufacturing.= The use of milling cutters and the
commencement of practically interchangeable manufacturing, came into
machine shop practice at nearly the same time. It has been said that
"but for the milling machine, there would have been no such thing as
interchangeable manufacturing." It might be said with quite as much
truth, that if the system of interchangeable manufacturing had not been
conceived, there would have been little need for the milling machine.
Each, to a great extent, depended very much upon the development of the
other──and upon a third factor, the conception and development of the
method of handling work (particularly small parts) in jigs and fixtures.
Milling cutters were made in America by one of the early machinists, a
Frenchman named Vaucanson, who died in 1782. A sample of these had a
hexagonal instead of a round hole, and the pitch of the teeth was very
fine, so that the cutter resembled a saw rather than those at present
in use. It is said that a man by the name of Bodmer, in Manchester,
England, had made a milling machine in 1824.
It is altogether probable that Eli Whitney, the inventor of the cotton
gin, had built and used milling machines previous to this date, as
the following item of mechanical history would seem to indicate. In
January, 1798, Eli Whitney received from the United States Government
an order to furnish ten thousand muskets, of which four thousand were
to be delivered in one year, and the balance in two years. Mr. Whitney
went at the undertaking in a very thorough and systematic manner.
He first developed a water power; then erected suitable buildings;
considered and developed ways and means for a larger and better product
than had previously been realized; designed and built machinery to
effect it; and trained workmen to a degree of skill necessary to
success in their new employment.
The difficulties which Mr. Whitney encountered and the obstacles
which he had to overcome, were so much greater than he anticipated
that it was really eight years instead of two before he had succeeded
in completing the government order for the ten thousand muskets.
However, the progress which he had made in this new enterprise, and the
character of the product which he turned out and delivered, were so
satisfactory to the government officials that Congress treated him with
the greatest courtesy and consideration.
His shops were situated in the city of New Haven, Conn., and soon
became the Mecca of government officials, manufacturers, traveling
notables, and foreigners, who had heard of this wonderful American
mechanic and came to see his work for themselves──to find that the
system, the machines, and the tools which he had perfected were well
worth the journey. His innovations in the manufacture of arms formed as
great an epoch in mechanical history as had his invention of the cotton
gin.
Jigs and fixtures were among his equipment; and it is altogether
probable that milling machines were also in use, since he must have had
practical knowledge of the utility of the milling cutter at this time,
as it is generally assumed that the first practical use of the milling
machine was in the making of parts of muskets.
The buildings which Mr. Whitney erected for his use were substantial
stone structures, and stand in a part of the city called in his
honor "Whitneyville." They form a part of the extensive plant of the
Winchester Repeating Arms Company.
At this point and at this early day, therefore, was inaugurated the
modern system of interchangeable manufacturing──or the manufacturing,
in large numbers, of duplicate parts, within such a limited degree
of variation as to admit of their ready interchangeability with
one another. The system was not one that would be confined to the
manufacture of arms, but was adaptable to the production of all kinds
of small and moderate─sized machinery, and was the initial effort
which in due time revolutionized the then existing shop methods, and
which has since built up the American system of manufacturing to the
proud distinction of being superior to anything of the kind in other
manufacturing countries.
In the operations of modern manufacturing, the principal object sought
is to turn out the product economically and accurately. To produce
these results economically, the parts must be produced very rapidly.
To produce them rapidly, not only must there be a very complete and
efficient equipment of machines, attachments, tools, jigs, fixtures,
and gauges or measuring devices, but there must also be a very complete
system of shop methods by which the operation of this equipment is
carried on.
It has been well said that "the man in whose brain the manufacturing
system was born was he who first took a piece of scrap iron and drilled
two holes in it, to guide a drill in making another piece with two
holes in it the same distance apart as in the first piece." The men
who now fill our drafting rooms and tool rooms, and who devise and
construct tools for the production of interchangeable metal parts,
are his descendants. They have made possible the manufacture of the
breech─loading gun, the typewriter, the cheap sewing machine, the cash
register, the machine─made watch, the automobile, as well as a thousand
and one other mechanical articles, machines, and devices which form an
integral part of our twentieth─century civilization.
To render these systems efficient and economical for these purposes,
the work must be _repetition or duplicate work_. That is, there must
be very large numbers of each of the different parts; and to carry out
the scheme of operation for the division and subdivision of work; a
single operation on a large number of parts is performed; then the work
is handled again, perhaps in another machine, and another operation
is performed; and so on until the part is complete. Thus a piece of
comparatively simple form may require a large number of separate and
distinct operations to complete it. But, as each single operation is
performed by one operator, he may give his undivided attention to the
accuracy of that operation; hence very accurate work can be produced.
[Illustration: A MACHINE SHOP WITH GALLERIES AT THE SHIPBUILDING
PLANT OF THE GAS ENGINE & POWER CO. AND CHARLES L. SEABURY & CO.,
CONSOLIDATED]
In the development of these systems, the work has continually grown
more and more complex, as have also the requirements as to the
buildings in which manufacturing work is performed, and as to the
equipment necessary to perform it. Conditions have been continually
changing; greater speed as well as greater accuracy in all machine
operations has been demanded; and a largely increased output per
employee has been required. So great and urgent has been this demand
that the employee of to─day will turn out from three to ten times the
volume of product of a given kind that he did only a few years ago.
Undoubtedly this result has been brought about in great measure by the
great improvement in machines, tools, and fixtures. Much is also due
to the use of tools composed of high─speed steel; still more, to the
employment of improved systems for handling work.
But all of these do not fully explain the enormous increase in product
per employee. This has been brought about by various methods of shop
management. One of these is the specialization of operations and
the division and subdivision of departments, whereby each operator
has a certain well─defined and very limited number of operations to
perform. These operations he performs over and over, hundreds and
sometimes thousands of times daily, until he becomes so accustomed to
each movement that the operations are performed not only with great
rapidity but also with great accuracy. Still another factor in the
question of individual output, is the efforts that have been made
through systems of premiums, bonus, and similar methods of reward for
individual effort when the output reaches or exceeds a certain fixed
limit. These rewards are not confined to the operatives, but are often
extended to the foremen, assistant foremen, gang bosses, and others
of the "non─productive" force who have indirectly contributed to the
efficiency of individuals and hence to departmental efficiency.
In the succeeding articles, these matters will be taken up and treated
in detail, giving the actual practice as now prevailing in some of the
best organized manufacturing plants.
MACHINE SHOP MANAGEMENT
=Modern Meaning of Shop Management.= The present understanding of the
term _Shop Management_ is quite different from the sense in which it
was used years ago. Formerly the management of the shop was vested
in a _superintendent_ whose duties consisted in purchasing material,
inspecting it when it was received, turning it over to the foreman,
and in a general way looking after the work as it was being performed.
In addition to these duties, he frequently handled the selling of the
product, the collection of accounts, and the proper provision for
meeting the pay─roll on pay─days. He also had a general supervision
over the grounds and buildings and their care and maintenance, as well
as the provision for power, lighting, and heating. By this arrangement
of duties, it will be seen that comparatively little time was devoted
to actual shop operations, and much time to different lines of duties
that might more economically and often quite as efficiently be
performed by assistants at a much lower rate of pay.
In the modern methods of shop management, all these things are changed.
The specialization of workmanship, the division of duties, the limiting
of responsibilities──each restricted within narrow limits by sharply
defined regulations──have reduced the variety of operations of the
workman, and of responsibilities and duties of the men who direct
manufacturing work.
We find the purchasing of material and supplies in charge of a
_Purchasing Agent_. We find these purchases checked by a _Receiving
Clerk_, turned over to a _Storekeeper_, and subject to examination by
a regular _Inspector_. They are then put into the storeroom, whence
they are drawn as needed for the different departments, the foremen of
which sign definite orders for such kinds, quantities, and qualities
as may be needed, specifying the purposes for which they are to be
used or the particular orders to which they are to be charged. When
issued, they are receipted for by the person receiving them. All
this is conducted with the same regard for business rules as if the
foreman were making a purchase on his own account and paying for the
goods. We find the selling of the product in the hands of an expert
_Sales Manager_, often assisted by a corps of engineers, draftsmen,
bookkeepers, and clerks, numbering more persons than the entire
factory's force of non─producers twenty years previously. A _Credit and
Collection Department_ attends to all collections, and the _Treasurer_
and _Cashier_ see to it that the money for the pay─roll is on hand when
wanted. A _Production Engineer_ regulates the volume of work going
into the shop, and the sequence of mechanical operations by which each
piece or part is to be machined and perfected. An assistant to the
Superintendent looks after the condition and maintenance of grounds and
buildings, yards, and the transportation facilities of the plant.
By these developments of the system of management into a division
of duties and responsibilities, the time, attention, and abilities
of the Superintendent may be devoted to his legitimate purposes of
_superintendence_ or _supervision_, planning and directing the work of
the assistants and heads of departments.
=A Typical Manufacturing Plant.= For the purpose of taking up the
question of Management in a systematic and practical manner, we must
first assume that we have a shop to manage; and secondly, that it is of
the usual type of manufacturing plant, built, organized, and managed at
the present day. The plan of such a plant is given in Fig. 1.
In planning a plant of this character, provision must primarily be made
for the various departments for the following purposes:
1. An _Engineering Department_, wherein the machines forming the
product may be designed and the drawings made for the various classes
of mechanics who are to perform the work of turning out the product.
2. A _Pattern─Making Department_, in which the necessary patterns are
made for use in the foundry for producing the castings.
3. A _Forge Shop_, capable of producing such forgings as are required
in the machinery to be built.
4. An _Iron and Brass Foundry_, in which may be produced the rough
castings of the parts that are to enter into the machines constituting
the product.
5. _Manufacturing Departments_, in which all parts (large and small)
of the product are made from the rough stock──such as castings,
forgings, bar stock, and the like, to the completed parts ready for
assembling.
6. _Assembling and Erecting Departments_, in which individual parts
may be assembled into groups of related parts, and these erected into
complete machines.
7. A _Power Plant_, containing the proper equipment for furnishing
the necessary power for driving the machinery in these various
departments, and for providing lighting and heating facilities for the
plant.
[Illustration: Fig. 1. Typical Layout of a Manufacturing Plant.]
The _General Office_ of the concern is of course understood; but, as
it cannot properly be classed with departments of the plant, it is not
included in the above enumeration.
In addition to the above list of principal departments, there will be
the following──quite as necessary, but secondary in importance:
1. The _Transportation System_, including shop and yard tracks and
cars, elevators, cranes, hoists, and all similar appliances for
handling material.
2. The _Tool Room_, for making tools, jigs, and fixtures, and for
properly storing them in a convenient manner for issuing when they are
called for.
3. An _Experimental Room_, which all progressive concerns find
necessary in the development of their product.
4. The _Store─Room_, in which are stored the raw material and the
purchased stock, either partly or completely manufactured, which are
issued to the different departments as needed for their daily routine
work.
5. The _Finished Parts Store─Room_, in which the smaller parts of the
product, as fast as they are completed, are stored and held until
wanted for the process of assembling.
6. The _Pattern Storage Room_. In this department, often occupying
several floors of a building specially constructed for this purpose,
are stored all patterns for the iron and brass foundries, and also
those sent to outside foundries for malleable and steel castings.
7. The _Carpenter Shop_. This is a general utility department making
boxes and crates for shipping; doing carpenter work in keeping the
grounds and buildings in proper repair, and making necessary changes
therein; making and repairing flasks for the foundry; and similar work.
8. The _Paint Shop_. A small room serving little more than as a
storeroom for paints and painters' materials, as their work is
principally done at various points in the shops, wherever the machines
or parts may happen to be.
9. The _Shipping Room_. In a plant building large machinery, the
shipping room is simply an office for the shipper, the physical work
of shipping being done in the shops, wherever the machine may happen
to be at the time.
Referring to the plan given in Fig. 1, it will be seen that the
Administration Building is placed in substantially the center of the
front line of the plant. The first and second floors of such a building
are usually devoted to administrative, commercial, and accounting
purposes. The upper floor is usually occupied by the Engineering
Department and drafting room.
The three Manufacturing Buildings numbered 1, 2, and 3 are devoted
to the various operations of making the parts of which the machinery
product is composed. These parts are then sent to the Erecting Building
(No. 4).
The system of shop transportation consists primarily of shop tracks and
cars, and is extended to the yard, being so designed as to connect all
buildings of the plant with one another and with the yard. It also
reaches the railroad tracks at numerous points. Overhead traveling
cranes cover the manufacturing buildings, and extend into the erecting
building far enough to form a connection with the large traveling crane
serving it, by which the large parts of machines are carried from place
to place as may be required by the erecting men. This crane serves to
load the finished machines upon the railroad cars, when they are to be
shipped, the railroad track being extended within the building for this
purpose, as shown in Fig. 1.
The Tool Room is given as central a location as possible, and would
naturally be near the junction of building No. 2 with the erecting
building.
The Experimental Room has no particular place, but is frequently so
placed as to be away from the active manufacturing operations, with
which it is liable to interfere if too closely related.
The general Store─Room for purchased material may be in the erecting
building, but is frequently located, for convenience of communication,
nearer the general offices──as for instance, in front of building No. 1.
The smaller parts are stored in a Finished Parts Store─Room, usually
located in this building. Thence they are issued to the Assembling
Department as required.
The Pattern Shop building will often be composed of three floors.
On the ground floor will be the Carpenter Shop and flask making and
repairing work. On the second floor will be the pattern─making shop,
and on the third floor will be the pattern storage rooms. A large
elevator serves all three floors.
The Paint Shop is sometimes located in one of the manufacturing
buildings or the erecting building; but as the painting of machine
parts and complete machines is generally done in any one of the
departments where the work may be, and the paint shop is hardly more
than a storeroom for paints, a due consideration of the question of
fire protection would indicate that it had better be placed in a small
building entirely detached from all manufacturing buildings.
The Power House, in the former method of transmitting power by shafting
and belting, was located as nearly as possible in the center of the
space over which power was to be distributed. Since the advent of
electricity and its common use for transmitting power, the question of
the location of the power house is relieved from this condition; it
may be located at the point most convenient to railroad facilities for
receiving fuel, or for obtaining the necessary water for boilers, for
fire purposes, etc.
In a plant manufacturing small machines or a kind of product which
is shipped in small quantities, it is obvious that the Shipping Room
must be convenient to the point from which these goods are to be
taken by railroad cars, by boat, or by teams. If most of the shipping
is of large machines or articles which must be handled by cranes,
the railroad tracks will be run into the erecting building, and the
machines loaded there, in order to avoid the expense of extra handling
and moving them. This is the arrangement shown in Fig. 1. In this case
the shipping room may be in the Administration Building, so as to be
convenient to the other office departments. In some kinds of business
it is convenient to have the shipping room and general storeroom near
each other, as there is considerable business done in each that is
quite closely related to the other.
The Iron and Brass Foundry is usually located at some distance from
the manufacturing buildings, in order that the latter may be as free
as possible from the annoyance of smoke and dust. It is connected
with the other departments by the system of shop and yard tracks, and
the railroad siding track passes through one end of the building as
a matter of convenience in shipping castings. There is also a branch
track running along the side of the foundry building for the purpose of
delivering coke, coal, moulding sand, pig iron, scrap iron, and other
foundry materials.
It should be noted that the buildings shown in the plan are located in
a compact mass, with considerably less than the usual yard room. In
this instance, however, the plan was so drafted to economize space on
the drawing. It is the law in some European countries that not over
50 per cent of the area of a manufacturing site shall be covered by
roofs. Such a law would be of much value in this country, to prevent
the crowding of buildings to such an extent as to be unhealthful to
employees.
While factory buildings are frequently erected of from three to to six
floors, the modern tendency is to reduce the number of floors in all
shops and manufacturing buildings; and in the case of machine shops,
a large majority of them are built of only one floor. Some, however,
have wide galleries at the side, by which considerable second─floor
space is added; while the central portion remains open to the roof, and
supplies ample space for the accommodation of the overhead traveling
crane, as well as the necessary added height needed for erecting large
machinery.
Foundries are necessarily built of a single floor, although there are
several in different parts of the country where moulding rooms are
located as high as the third floor. This latter arrangement is usually
made for brass moulding, rather than for iron moulding.
=Organization of a Manufacturing Plant.= Having the design of the
plant, and assuming that the required buildings have been erected
in accordance with this plan, the next step will be to organize
the management both in a general way and also as relates to the
various departments usually necessary to inaugurate the business of
manufacturing.
As the scope of this treatise covers only the shop and its management,
we need not take up the commercial organization of the company by
which it is capitalized and maintained. We shall therefore consider
the General Manager as the head of the organization, and proceed to
examine the methods usually adopted for the division of authority and
responsibilities from him to the actual workmen at the bench, at the
machines, and on the floors.
The chart shown in Fig. 2 illustrates the plan of the organization.
Nearly all minor officials and office employees, such as bookkeepers,
clerks, stenographers, etc., are omitted from this chart, to avoid
confusion and to simplify the understanding of the organization plan
and its numerous details.
The General Manager has a personal Assistant, and, for his commercial
affairs, the service of a commercial Accountant and a Cashier. Other
office employees are similar in number, duties, and responsibilities to
those in the usual commercial office.
By referring to the chart, it will be seen that the organization
is divided into two distinctly different parts. First, that of
_production_ or _manufacturing proper_; and second, that of _selling_
or _marketing_ the output produced.