Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02280414 2000-03-20
ZONE INSPECTION MANUFACTURING LINE
RELATED APPLICATION
This application is related to a second patent application entitled Assembly
Line Control
System, the inventors being Rick Madden and Jeff French. The specification for
the Assembly Line
Control Systems forms part of the instant specification and is attached hereto
as Appendix A.
FIELD OF THE INVENTION
The present invention is directed to an improved automobile manufacturing line
wherein the
manufacturing line is divided into functional zones with inspection and repair
being performed at
each zone.
BACKGROUND TO THE INVENTION
A conventional automobile manufacturing line, such as that disclosed in
Japanese laid open
publication no. 4-250958, has an inspection department, wherein static and
dynamic functional
inspections are performed, at the end of, and after, a plurality of assembly
lines and processes. In
the case of a problem or defect, the defective vehicle is sent to a repair
department for processing,
which, again, is at the end of the plurality of assembly lines. The repair
department then performs
the necessary repairs. The vehicle, upon completion of any necessary repairs,
is then complete.
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In recent years, the inspection and repair processes of these automobile
manufacturing lines
have been equipped with computers for data input and display. The assembly
line worker, known
within Honda as an associate, in charge of the inspection process enters the
problem items in the
computer. The problem items, or defects, are then displayed in the repair
department. Repairs
conducted on any defective vehicles correspond to and are based on the problem
items displayed by
the computer.
In the conventional assembly described above, static and dynamic functional
inspection of
a vehicle is performed in a Vehicle Quality department which is located at the
terminus of the
assembly process. All of the defects and problems that occur during the entire
assembly process are
repaired in the repair department of the Vehicle Quality department. When a
large number of
problems are identified, such as defects identified during an exterior
inspection which may be the
result of a defect caused early in the assembly process, the repair
department, which has the
responsibility for repairing the identified defects, may be overwhelmed.
Moreover, isolating the
cause of problems identified in the Vehicle Quality department becomes
difficult as the vehicle
quality is only assessed as a final process in its overall assembly. Further,
the data corresponding
to these problems and their solutions, which is, conventionally, transmitted
from the repair
department to other production departments, becomes excessively large.
Accordingly, it is desired to provide a method of manufacturing an automobile
which
addresses these shortcomings.
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SUMMARY OF THE INVENTION
An improved assembly line process is achieved by dividing the assembly line
into a plurality of
zones by static function (interior, appearance, etc. ). Each functional zone
is responsible for a static
functional inspection and the repairs of identified defects. Static functional
inspections assess non-
operational characteristics of an assembly. Thus, by assessing and repairing
static functional defects,
the static functional quality of a vehicle is improved at each functional
zone. Moreover, the
production efficiency is improved and the quality of the entire assembly line
is stabilized at an early
stage of assembly since these vehicles are inspected and repaired early in the
manufacturing process.
The present invention is directed to an automobile assembly line wherein a
plurality of
assembly lines following the course of the line are divided into a plurality
of functional zones. At
the end of each functional zone is an inspection/repair process that is
responsible for static functional
inspection and light repairs of defects of any vehicle entering the
inspection/repair process of the
functional zone. A functional zone's inspection/repair process is equipped
with a data entry and
display system so that all defects identified in that particular zone can be
entered into the data entry
system together with any problem items or defects that could not be repaired.
The main characteristic
of this data entry and display system is that it is not only configured to
display all of the identified
and/or repaired defects of a particular zone but the data entry and display
system is also connected
to the data entry and display systems of other production-related departments.
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The assembly line of the present invention is designed so that there is an
inspection process
for each functional zone and each individual functional zone has its own
inspection area and can
perform some of its own repairs.
Further, the repair process of each functional zone is able to perform many of
the repairs that
typically develop in that functional zone. Moreover, the repair area may also
attempt to remedy
those defects entered into the data input and display system in the inspection
processes of other
functional zones. Each repair process also may determine if the capability to
remedy an identified
defect is available at that repair process. If the remedial capability exists,
a repair is made. Each
functional zone may also display a countermeasure to prevent further defects.
If possible the
countermeasure to address the suspected cause of the defects may be
implemented on the assembly
line.
As a result, it is possible to implement countermeasures for the problem items
or defects
identified and pertaining to the assembly process of a particular functional
zone.
Further, the invention may provide, through the data entry and display system,
the capability
to enter and provide to the production-related departments, a wealth of data.
This data may include,
for example, the capabilities of a particular functional zone's repair area
and the problem items or
defects that can be repaired in that particular functional zone, cause of a
defect, a summary of the
repairs performed and the time required to repair a defect.
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In case of problem items or defects that are not possible to repair in a
particular functional
zone, data on the problem item or defect may be transmitted into the data
entry and display system
which can then be provided to other production-related departments, such as,
for example, repair
departments.
All the problem items that can be repaired in a particular functional zone are
repaired and
countermeasured. That is, an attempt to address the suspected cause of the
defects is implemented.
But, problem items or defects that cannot be repaired in a particular zone are
repaired in a repair
department located at the end of the entire assembly line. The countermeasure
to address the cause
of the defect is then transmitted or fed back to the particular functional
zone which caused the defect.
In this way, the cause of the problem that could not be repaired in a
particular functional zone may
be addressed so that further defects from this cause are reduced promptly.
Even during the period
of production start-up, the assembly as well as the quality of static
functionality can be improved and
stabilized by the operation of the functional zones.
Further, the present invention is directed to an automobile assembly line that
improves and
may guarantee the repair of all identified problems. Problem items or defects
that cannot be repaired
at a particular zone inspection process are repaired at a complex quality
assurance zone. As a result,
all the identified problems that are not repaired at each functional zone can
be completely repaired.
According to one aspect of the invention, there is provided an apparatus for
assembling
comprising: a plurality of assembly lines each manufacturing an assembly; each
of said plurality of
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assembly lines comprising: a plurality of functional zones; and each of said
functional zones having:
a zone for assembly; an inspection area for identification of defects; and a
repair area for repairing
identified defects; and a communications network providing communication
amongst said plurality
of functional zones of said plurality of assembly lines.
According to another aspect of the invention, there is provided a method of
manufacturing
comprising: manufacturing a sub-assembly at each of a plurality of sub-
assembly lines;
manufacturing an assembly incorporating each of said sub-assemblies at a
primary assembly line;
at each of said plurality of sub-assembly lines: inspecting said sub-assembly
for defects at each of
a plurality of functional zones spaced along said each sub-assembly line;
where possible, repairing,
at said each functional zone, defects identified during said inspecting of a
given sub-assembly at said
each functional zone and defects identified during said inspecting of said
given sub-assembly at
functional zones upstream of said each functional zone; and transmitting for
use by other sub-
assembly lines of said plurality of sub-assembly lines data related to defects
identified and defects
repaired at said each of said functional zones.
According to another aspect of the invention, there is provided a method of
assembly,
comprising: at a first functional zone on a first assembly line in
communication with a second
assembly line: assembling a first assembly; inspecting said first assembly for
defects;
communicating results of said inspecting of said first assembly to said second
assembly line; where
possible, repairing at least some of said first functional zone defects; and
communicating results of
said repairs to said second assembly line; at a second functional zone on a
second assembly line:
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receiving said results of said inspecting and said repairing communicated from
said first assembly
line; and assembling a second assembly responsive to said inspecting and
repairing results received.
According to another aspect of the invention, there is provided a method of
assembly,
comprising: at a first functional zone on a first assembly line: assembling at
an assembly zone a
first assembly; inspecting at an inspection zone said first assembly for a
first set of defects; and at
a repair zone, where possible, repairing at least some of said first set of
defects; at a second
functional zone on a second assembly line: assembling at an assembly zone a
second assembly
incorporating said first assembly; inspecting at an inspection station said
second assembly for a
second set of defects; and at a repair zone, where possible, repairing at
least some of said first set of
defects and said second set of defects; and communicating said defects
identified and said repairs
performed at said first functional zone to said second functional zone and
said defects identified and
said repairs performed at said second functional zone to said first functional
zone.
According to another aspect of the invention, there is provided a system for
tracking an
assembly comprising: a receiver for receiving signals from a plurality of
assembly lines; each of
said assembly lines comprising: a plurality of functional zones; and each of
said functional zones
having: a zone for assembly; an inspection area for identification of defects;
and a repair area for
repairing identified defects; and said signals containing information
corresponding to defects
identified at said inspection area and repairs performed at said repair area
of each of said plurality
of functional zones of each of said plurality of assembly lines; a transmitter
for transmitting signals
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to said plurality of functional zones of said plurality of assembly lines,
said transmitted signals
containing information relating to said information received by said receiver.
According to another aspect of the invention, there is provided an assembly
line comprising:
a plurality of functional zones, each functional zone having, in downstream
order, an assembly area,
an inspection area for identifying defects, and a repair area for repairing
defects; a communication
terminal associated with each said assembly station, inspection station, and
repair station; a
communication network interconnecting each said communication terminal and
having a remote
network connection to another assembly line; memory associated with said
communication network
for storing build sheet data and assembly sheet data for each said functional
zone; at least one
processor associated with said communication network for modifying said
assembly sheet data based
on input from communication terminals and input received over said remote
network connection.
According to another aspect of the invention, there is provided a method of
operating an
assembly line, comprising: at each of a plurality of functional zones: at an
assembly area, receiving
current assembly sheet and build sheet data from a communication network and
assembling in
accordance with said data; at an inspection area, inspecting an assembly
output from said assembly
area for defects and outputting defect data to said network; at a repair area,
receiving defect data
from said communication network, repairing said assembly based on said defect
data, and outputting
repair data to said communication network; receiving countermeasure data from
another network
associated with another assembly line; developing countermeasure data based on
said repair data;
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modifying at least one of said assembly sheet data and said build sheet data
based on said
countermeasure data.
According to another aspect of the invention, there is provided a method for
operating
assembly lines, comprising: providing, to an assembly area of each of a
plurality of serially arranged
functional zones of each of a plurality of assembly lines, current assembly
sheet and build sheet data;
receiving from an inspection area of each of said plurality of functional
zones, data relating to
identified defects; receiving from a repair area of each of said plurality of
functional zones, repair
data; sending to at least some of said plurality of functional zones of a
given assembly line, defect
data received from a functional zone of said given assembly line upstream of
said at least some of
said plurality of functional zones; developing countermeasures based on
received defect data and
repair data; and revising assembly sheet and build sheet data based on said
developing.
According to another aspect of the invention, there is provided a computer
software media,
which when loaded into a process adapts said processor to: provide, to an
assembly area of each of
a plurality of serially arranged functional zones of each of a plurality of
assembly lines, current
assembly sheet and build sheet data; receive from an inspection area of each
of said plurality of
functional zones, data relating to identified defects; receive from a repair
area of each of said
plurality of functional zones, repair data; send to at least some of said
plurality of functional zones
of a given assembly line, defect data received from a functional zone of said
given assembly line
upstream of said at least some of said plurality of functional zones; develop
countermeasures based
on received defect data and repair data; and revise assembly sheet and build
sheet data based on
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developed countermeasures.
BRIEF DESCRIPTION OF THE DRAWINGS
Other aspects and features of the present invention will become apparent to
those ordinarily
skilled in the art upon review of the following description of specific
embodiments of the invention
in conjunction with the accompanying figures wherein:
Figure 1 illustrates the basic structure of a first automobile assembly line
embodying the
invention.
Figure 2 illustrates, schematically, a first portion of a functional zone of
the automobile
assembly line of Figure 1.
Figure 3 illustrates, schematically, a second portion of the functional zone
of Figure 2 and
a computer network of the automobile assembly line of Figure 1.
Figure 4 illustrates another portion of the automobile assembly line of Figure
1.
Figure 5 illustrates the basic structure of a second automobile assembly line
embodying the
invention.
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Figure 6 illustrates, schematically, a second portion of the automobile
assembly line of
Figure 5.
Figure 7 illustrates, by flow chart, operation of assembly line of Figure 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referencing Figure l, automobile assembly line 1 is divided into an assembly
area 2 and
complex quality assurance zone 3.
Assembly area 2 comprises a plurality of functional zones that follow the
course of
automobile assembly line 1. As illustrated, for exemplary purposes only,
assembly area 2 is divided
into functional zone A 10, functional zone B 20, functional zone C 30 and
functional zone D 40.
The processes and assembly that are performed in a particular functional zone
are dependent upon
a wide variety of factors including, for example, the speed of the assembly
line, the overall design
of the vehicle, the formation of a conventional portion of a vehicle (such a
front engine room
component, passenger cell, truck bed, etc.), as well as many others.
Each functional zone, A 10, B 20, C 30 and D 40, comprises a functional
assembly zone (12,
22, 32 and 42, respectively), wherein a plurality of assembly processes are
performed, and thereafter,
an inspection/repair zone ( 14, 24, 34 and 44, respectively), wherein the
functional zone performs its
own static functional inspection and repairs. In this manner each functional
zone inspects the
partially constructed vehicle for defects and problem items relating to such
areas as, for example,
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the outer appearance and exterior and interior static function related items.
In the exemplary
embodiment all dynamic function related items are excluded from the functional
inspection zones.
As will be obvious to those skilled in the art, static functional inspection
assesses non-operational
characteristics of an assembly. For example, the tolerances of welds, the
inclusion of the requisite
parts, etc. In contrast, functional inspection assesses the operation of an
assembly. For instance, the
operation and inter-operation of the transmission and the engine, the
operation of electric window
lifts, etc.
As illustrated, assembly area 2 comprises functional zone A 10, functional
zone B 20,
functional zone C 30 and functional zone D 40. Functional zone A 10, like
functional zones B - D
(20, 30 and 40, respectively), comprises a functional assembly zone A 12 and
an inspection/repair
zone A 14. Functional assembly zone A 12 performs various assembly processes,
such as, for
example, the welding of front engine room or bay component, similar to a
conventional assembly
line. However, unlike a conventional assembly line, functional zone A 10
incorporates, downstream
of functional assembly zone A 12, inspection/repair zone A 14.
Inspection/repair zone A 14 performs a static inspection of the partially
completed vehicle
upon the vehicle's departure from functional assembly zone A 12. During the
inspection of the
partially completed vehicle, defects and other problem items may be
identified. Hereafter, defects
and problem items are used interchangeably to designate any portion of a
vehicle that is outside the
quality specification tolerances. The inspection of the vehicle may include
the performance of a pre-
determined set of routines or methods, such as for example, a visual or touch
inspection of the
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partially completed vehicle that may, for example, check the tightening of
various fasteners, the
connection of wire assemblies, body defects or deforms, etc. Moreover,
inspection/repair zone 14
also has repair capabilities in which, if possible, defects or problem areas
identified previously are
repaired. These repair capabilities are configured so as to be able to
complete certain repairs without
stoppage of assembly line 1. As will be obvious to a person skilled in the
art, an automobile
assembly line configured in accordance with this invention will improve
production efficiency by
the identification and repair of defects and other problem items in-line and
as close to the location
of the cause of those defects as possible. Moreover, incorporating
inspection/repair zone A 14
within functional zone A 10 improves the static quality of a partially
assembled vehicle prior to the
vehicle reaching complex quality assurance zone 3.
Similar to functional zone A 10, functional zone B 20 is comprised of
functional assembly
zone B 22 and inspection repair zone B 24. Similarly, functional zone C 30 is
comprised of
functional assembly zone C 32 and inspection/repair zone 34 and functional
zone D 40 is comprised
of functional assembly zone D 42 and inspection/repair zone 44. Functional
assembly zones B 22,
C 32 and D 42 perform conventional assembly processes.
With the assistance of a computer system 300 (Figure 3) equipped for data
input and display,
information pertaining to defects or problem items; repairs performed; and
repairs not performed are
input into the computer system 300 and the data is transmitted to and
displayed on computer
workstation located in complex quality assurance zone 3. As will be described
later in greater detail,
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CA 02280414 1999-08-16
complex quality assurance zone 3 is comprised of complex quality inspection
process area 3a and
dress up process area 4, as well as other production related departments.
As described heretofore, static functional inspection of a partially completed
vehicle,
including, for example, inspection of the exterior, interior, connections, and
others, is performed at
each of the functional zones of automobile assembly line 1 based on inspection
specifications. As
a result of the data input, complex quality assurance zone 3 is informed, by
the display of data on
a computer workstation forming part of computer system 300, of defects or
problem items that could
not be repaired upstream of complex quality assurance zone 3. Complex quality
assurance zone 3
also performs an overall complex quality inspection of the vehicle and the
inspection results are then
entered in a final inspection card - a paper record which has data
corresponding to a particular
vehicle's assembly. Further, complex quality data is input into the computer
workstation of the
computer system 300, described in detail below, located at complex quality
assurance zone 3.
In case of any problem items identified as a result of the inspection at
complex quality
inspection process 3a, data corresponding to these identified defects is input
into computer system
300 and transmitted to and displayed at dress up process 4.
Finally, data from the final inspection card is input into a computer station
of computer
system 300 located in complex quality assurance zone 3. This data is then
transmitted and is
available for display at other computer workstations of the computer system
which are located in
other production related departments.
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Defects or problem items that could not be repaired at inspection/repair zones
A 14, B 24,
C 34 or D 44, together with those items identified at complex quality
assurance inspection process
area 3a are then repaired at dress up process 4.
Briefly referencing Figure 4 along with Figure 1, as will be described later,
dress up process
4 comprises an in-line repair process 6 and a line side repair process 7 for
any problem items that
could not be repaired in functional zones A 10, B 20, C 30 and D 40 (see
Figure 4).
In the same way that complex quality inspection area 3a is equipped with a
computer
workstation for the input and display of data from computer system 300, dress
up process 4 is also
equipped with a computer for data input wherein repair details of items
repaired in-line, as well as
repair contents of items repaired out-of line, and in side line process 7, are
entered. This data is then
displayed on computer screens or data outputs in other production-related
departments that are
equipped with access to computer system 300.
Figure 2 illustrates, an exemplary structure of a functional zone A 10 of
automobile assembly
line 1. Moreover, functional zone A 10 is exemplary of the possible structure
of other functional
zones, such as functional zone B 20, functional zone C 30 and functional zone
D 40.
As illustrated, functional zone A 10, is comprised in part of a plurality of
assembly processes
A, B, ...,N, 202A, 202B, ..., 202N, respectively, and zone inspection process
14. Assembly
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processes 202A - 202N install parts and perform some assembly of the partially
completed vehicle.
As illustrated in the exemplary embodiment, assembly process A 202A may
install a nozzle, an
ABS modulator, an insulator, a filler pipe and an interior cord set.
Similarly, assembly process N
202N of functional zone A 10 may install the starter cable, the horn and a
slide door stopper.
Further, a high degree of quality during the assembly and processing of a
partially completed
vehicle in assembly processes 202A - 202N is enhanced with the assistance of
set methods on
assembly and processing, including the use of, for example, mechanical jigs,
so that defects or
problem items such as foreign substances, contaminants, bending or twisting of
components,
insufficient torque, etc., are reduced.
As illustrated, zone inspection process 14, responsible for the inspection and
repair of, for
example, interior parts, is passed a partially completed vehicle, which
arrives upon completion of
assembly processes 202A - 202N. Inspection process 14A is responsible for the
inspection of the
partially completed vehicle. Following inspection process 14A, and forming
part of
inspection/repair zone A 14, is repair process 14B, which is responsible for
performing in-line
repairs to the partially completed vehicle. The main objective of
inspection/repair zone A 14 is to
identify and repair any problem items or defects and ensure a high level of
quality of a partially
completed vehicle exiting the functional zone, in this case functional zone A
10.
Based on a variety of possible inspection methods which may include such as,
for example,
visual, measured or gauged inspection, touch and check sheet inspections, all
of which may be
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performed manually, automatically or by a combination of the two, an
inspection of the partially
completed vehicle is performed on, for example, the outer appearance, fit and
finish, and parts
assembly. This inspection is designed to identify any out of specification
static quality items relating
to, for example, a vehicle's outer appearance, deforms, float, wrong assembly
and others.
Repair process 14B then performs repairs to problem items identified
previously, including
those identified during the inspection performed by inspection process 14A. In
repair process 14B,
it is determined whether repairs to particular problem items may be performed
by repair process 14B
based on its capabilities. It is also determined whether, based on a variety
of factors, including, for
example, line speed, a necessary repair to an identified problem can be
completed in-line and within
a specified time period. This time period may, for example, be a set number of
minutes or seconds.
It is desirable that problem items that may affect the process of the next
functional zone be repaired
prior to the partially completed vehicle entering the next functional zone.
Inspection process 14A and repair process 14B are equipped with computer
stations for the
input of data into computer system 300 (Figure 3). Therefore, problems
identified in inspection
process 14A are entered into computer system 300. This entry may be performed
automatically,
manually or through a combination of the two methods. Repair process 14B
performs repairs based
on the data displayed by computer system 300. Further, data is entered into
computer system 300
that corresponds to items left partially unrepaired. All of this data is then
available for display on
computer screens of computer stations connected to computer system 300. These
computer stations
are, as described later, available in functional zone 10 and in other
production related departments.
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Figure 3 explains the zone inspection process and outline of computer system
300, which,
as illustrated, incorporates a computer Local Area Network (LAN). Only a
portion of the LAN of
computer system 300 is illustrated, for purposes of ease of understanding and
removal of repetitive
portions. Computer system 300 incorporates a plurality of computer stations
310 and a host
computer 302 connected to a backbone 304.
In communication with host computer 302 is computer software medium 305.
Computer
software medium 305, which contains instructions and data for host computer
302, is readable by host
computer 302. Computer software medium 305 may contain, for example, database
software,
computer applications, computer data, network software, data corresponding to
the layout of
automobile assembly line 1 (Figure 1 ), or the like. While computer software
medium 305 is
illustrated as a computer diskette, it could equally be a tape, memory chip,
or other removable or
non-removable computer readable medium. Furthermore, the software medium may
be a remote
medium, such as a memory of a remote computer, and be downloaded over a
suitable link such as
over an network, Internet, intranet, dedicated data link, or the like.
As described above, each functional zone, that is, functional zones A 10, B
20, C 30 and D
40 (Figure 1 ), has a plurality of workstations capable of data entry and data
display. Specifically,
and as illustrated in greater detail in Figure 3, the inspection/repair zones
of each functional zone (as
illustrated inspection/repair zone 14 of functional zone A 10) has a computer
workstation 310 in each
of the inspection and repairs processes (here, inspection process 14A and
repair process 14B). The
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various assembly processes (such as assembly process A-N, 202A - 202N, shown
in Figure 2) may
also have computer workstations proximally located thereto).
The computer workstation in the inspection process 14A comprises an input
device, such as
bar code scanner 330, and a data display device, such as touch panel display
332, which, in this case,
is capable of both the display of data and the entry of data into computer
system 300.
The computer workstation in the repair process 14B also comprises an input
device, such as
bar code scanner 340, and a data display device, such as touch panel display
342, which, in this case,
is capable of both the display of data and the entry of data in computer
system 300.
Figure 3 also illustrates the various processes that are performed in
inspection/repair zone
14. As illustrated, inspection process 14A determines a particular vehicle
identity through the use
of, for example, bar code scanner 330 which reads a vehicle's vehicle
identification number (VIN).
In response to the reading of the VIN, an "assembly specification sheet" is
retrieved from the
memory of host computer 302 and transmitted and displayed on touch panel
display 332 of the
computer workstation located in inspection process 14A. Based on the
specification sheet retrieved
and displayed on touch screen 332, an inspection routine is performed on the
partially assembled
vehicle located within inspection process 14A.
Inspection results and the problem items identified during the inspection
routine are then
entered into workstation 310 of inspection process 14A, via touch screen 332,
and form part of the
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data available on computer system 300. The data so entered is then fed back
and available for
display at all of the production-related departments.
In repair process 14B, the "assembly specification sheet" is retrieved in the
manner described
in reference to inspection process 14A. Moreover, the action of bar code
scanning the partially
assembled vehicle's VIN also provides repair process 14B with data
corresponding to the problem
items and defects identified so far, including those problem items identified
by and entered into
computer system 300 during inspection process 14A through use of touch screen
332. Based on the
defects and problem items displayed on display 342, a determination is made as
to whether to
perform the necessary repairs. For defects or problem items that are possible
to repair, based on a
variety of factors including, for example, time available, the capabilities of
the repair process 14B
and others, repairs are commenced and completed based on the repair standards
and routines. Data,
corresponding to both the problem items repaired and those not repaired, is
entered, through use of
touch screen 342, into computer system 300. This data is then available for
display on the computer
workstations 310 in the particular functional zone, in this instance
functional zone A 10, and those
of all the other computer workstations 310 in the other production related
departments.
By having an inspection and repair process at the end of each fi~nctional
zone, the quality of
partially completed vehicles exiting each functional zone is improved.
Moreover, data and
information regarding defects and problem items not repaired can be provided
to the required
departments such as, for example, complex quality inspection process 3a and
dress up process 4.
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Further, defects and problem items of a particular functional zone can be
repaired and this
repair data is then fed back to the assembly process of that particular zone
and, as a result, repair
information is immediately available to the whole of automobile assembly line
1 and may be used
to implement countermeasures to prevent further problem items or defects.
Further, based on the repair data fed back from dress up process 4, repair
information is
transmitted back to the assembly process, for example processes 202A - 202N,
of a particular
functional zone and, as a result, it is possible to improve the quality of a
particular functional zone
as the time delay between introducing a defect- or problem item-creating error
is reduced. Therefore,
the causes of the defects and problem items are easier to determine and the
time to respond to these
causes is also reduced.
Figure 4 explains the structure of an exemplary dress up process 4. As
illustrated, dress up
process 4 comprises in-line repair process 6 and line side repair process 7.
Defect and problem item
data entered into computer system 300 in each of the functional zones, A 10, B
20, C 30 and D 40,
is displayed on a computer display of a computer workstation located in in-
line repair process 6.
This information may be retrieved by a manner similar to that in inspection
process 14A and repair
process 14B. That is, the information relating to a particular vehicle may be
retrieved from host
computer 302 by scanning the vehicle's VIN through use of a bar code scanner.
Based on the defect
and problem item data retrieved, repairs that are able to be completed in-line
are performed by in-
line process 6. After the completion of in-line process 6, the static quality
of a vehicle, with the
exception of those items that are not capable of being repaired in-line, is
guaranteed to be within the
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static function specifications (an "in-spec" vehicle). An "in-spec" vehicle is
then conveyed to the
dynamic function inspection process 10, which is the next process set in the
assembly line.
Defects and problem item data from each of the inspection processes of each of
the
functional zones, A 10, B 20, C 30 and D 40, is also displayed, in a manner
described above, on the
display screen the computer workstation located within side repair process 7.
Based on the problem
item data, problems that could not be repaired in-line, by the plurality of
repair processes in
inspection/repair zone A 14, inspection/repair zone B 24, inspection/repair
zone C 34 and
inspection/repair zone D 44 and in-line process 6 (for example, repairs that
require more time and
are not suited to in-line repair) are repaired completely in line side repair
process 7. Vehicles
repaired in line side repair process are then transported to dynamic function
inspection process.
Vehicles transported to dynamic function inspection process are guaranteed to
be "in-spec" with
respect to the static functional specifications.
Upon completion of the dynamic function inspection process 10 (which may
include repairs
to remedy any dynamic functional defect) the dynamic functional quality of a
vehicle is guaranteed
to be "in-spec".
As was the case in the other zones described heretofore, both in-line repair
process 6 and line
side process 7 are equipped with an data entry system in computer system 300
for the input of data
which corresponds to the repairs completed. This repair data is then available
for access or display
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at the other production related departments which include functional zones A
10, B 20, C 30 and D
40.
As is obvious to a person skilled in the art, in dress up process 4, which
comprises in-line
repair process 6 and line side repair process 7, all identified defects and
problem items that were not
repaired in functional zones A 10, B 20, C 30 and D 40, are repaired with the
result that quality of
static functionality of a vehicle is guaranteed.
Further, since repair data of each functional zone and repair data from
complex quality
assurance zone 3 and dress up process 4 is fed back to the rest of automobile
assembly line 1, defects
and problem items are reflected on assembly line 1 immediately upon
identification and immediately
upon repair. As a result, countermeasures can be undertaken thereby
stabilizing the quality of a
vehicle soon after production start up.
A second embodiment of the invention is illustrated in Figure 5. Figure 5
illustrates an
automotive assembly process 500 having a plurality of assembly lines, namely
primary assembly
line 510, engine/front suspension assembly line 520, door assembly line 530,
instrument panel
assembly line 540, and rear suspension assembly line 550: (collectively sub-
assembly lines 560. The
sub-assembly lines 560 can each operate in a manner similar to that of
automobile assembly line 1
(Figure 1 ).
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While the plurality of assembly lines (510, 520, 530 and 540) are illustrated
as being
proximate to one another and within the same plant, as those skilled the art
are aware, it is common
in the automotive industry to have subassemblies produced at different sites
from the final assembly
of the vehicle. The embodiment illustrated in Figure 5 is viable where the
various subassemblies
produced by engine/front suspension assembly line 520, door assembly line 530
and instrument
panel assembly line 540 and rear suspension assembly line 550 are produced at
different physical
sites. In such a case, data corresponding to defects, repairs performed and
repairs required to be
performed is shared amongst the various sub-assembly sites by way of a Wide
Area Network
(WAN), Virtual Private Network (VPN) or the like. Moreover, the subassemblies
need not be
produced by a single entity, such as Honda, but could be produced by number of
entities in
cooperation.
As described above, in conjunction with the first embodiment, each of the sub-
assembly
lines, namely engine/front suspension assembly line 520, door assembly line
530, instrument panel
assembly line 540 and rear suspension assembly line 550, will each be divided
into functional zones
570 with each functional zone comprising a functional assembly zone 582 and an
inspection/repair
zone 584. As described heretofore, the functional assembly zones of sub-
assembly lines 560 will
carry out the conventional processes to assemble a portion of a vehicle, for
instance, an engine/front
suspension assembly, a door assembly, an instrument panel or a rear suspension
assembly.
Depending on the nature of the sub-assembly, it may be preferable not to
include a complex quality
assurance zone 572, similar to complex quality assurance zone 3, as the added
benefits provided by
an complex quality assurance zone at the end of the sub-assembly line may not
be sufficient to
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warrant the inclusion of an additional complex quality assurance zone.
Moreover, the sub-assembly,
once installed on the vehicle, will be inspected, and if necessary, repaired
in the complex quality
assurance zone 572 which is a part of primary assembly line 510. However, in
some instances, it
may be preferable for the sub-assembly line to include all of the
functionality of automobile
assembly line 1 (Figure 1 ). That is, (as illustrated for door sub-assembly
line 530) the sub-assembly
line may comprise a plurality of functional zones 570, a complex quality
assurance zone 572 and a
dynamic functional inspection process 574. This may be preferable where a sub-
assembly line and
the primary assembly line are not physically located proximate to one another.
The sub-assembly lines 560 may be formed by grouping functional zones that are
related to
a distinct portion of the partially assembled vehicle and that can be
assembled in parallel to other
portions of the vehicle.
Regardless of the inclusion of final inspection areas (such as complex quality
assurance zone
572 and dynamic function inspection processes 574), each of the sub-assembly
lines 560 is
functionally divided into functional zones 570 with each function zone
comprised of a functional
assembly zone 582 and an inspection/repair zone 584. Moreover, each functional
zone 570, and
therefore each of the assembly, inspection and repair processes therein, are
in communication with
each other through a communications system, such as computer system 600
(Figure 6).
In the exemplary embodiment of Figure 5, sub-assembly lines 520, 540 and 550,
shown in
dotted outline, are physically located at sites removed from primary assembly
line 510 and door
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assembly line 530. That is, instrument panel sub-assembly line 540 is located
at a different physical
location (i.e., not in the same plant) from that of primary assembly line S
10. Similarly, engine/front
suspension assembly line 520 is also located at a site different from that of
primary assembly line
S 10 and, possibly, at a different location from instrument panel sub-assembly
line 540. Further, rear
suspension sub-assembly line 550 is also located a site different from that of
primary assembly line
510, and may different from that of engine/front suspension sub-assembly line
520 and/or rear
suspension sub-assembly line 550. There may be many reasons for locating the
sub-assembly lines
at a different plant (or plants) from that of main assembly line including,
but not limited to: the cost
of providing an engine foundry at the primary assembly line site; local
expertise in manufacturing
a particular product; local environmental concerns for producing a particular
product; labour costs;
and the like.
The sub-assemblies manufactured at these off site sub-assembly lines (i.e.,
sub-assembly
lines 520, 540 and 550) will be shipped to the location of primary assembly
line 510 where the sub-
assemblies will be installed into a vehicle.
The sub-assemblies produced at the off site sub-assembly lines 520, 540 and
550 are, as
described above, inspected during manufacture and, if defects are identified,
repaired prior to
transport to primary assembly line 510. However, as is known in the industry,
the sub-assemblies
produced may not arrive defect-free due to damage caused during transport.
Moreover, it may be
the case where, when the sub-assembly is viewed in isolation (i.e., without
reference to the
remainder of the vehicle), the sub-assembly is considered to be free of
defects. However, due to the
complexity of large scale integrated products, such as, for example, an
automobile, defects are
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identified when the sub-assembly is to be installed into the final assembly,
such as the automobile.
These defects may be, for example, misalignment of parts (such as fastening
devices, such as, bolt
holes), interference of the sub-assembly with other parts of the main
assembly, incorrect sub-
assemblies being shipped, incorrect number of sub-assemblies being shipped,
and the like.
Moreover, changes in the production schedule of primary assembly line 510 (due
to, for example,
defects being identified with some parts on primary assembly line 510) may
require changes in other
parts supplied to primary assembly line 510 in order to reflect the scheduling
changes. For example,
it may be the case that due to an identified defect, such as, for example, a
parts shortage of one
particular type of component (for example, a specific type of seating system
may not be available,
such as, for example, leather seating), causes primary assembly line 510 to be
unable to manufacture
a specific automobile type (such as a luxury version of a particular model
type - e.g. a HondaTM
AccordTM EX-R). In such an instance, the vehicle or assembly that cannot be
provided to primary
assembly line 510 may impact the parts required from sub-assembly lines 520,
540 and 550. In the
above example, namely the lack of availability of leather seats, the luxury
version of the automobile
that was to have been produced, may have had a type of engine/front suspension
sub-assembly, or
instrument panel sub-assembly or rear suspension sub-assembly that was unique
to that version of
the model type. In such an instance, the production schedule may change to
ensure that the primary
automobile assembly line 510 is not idled. The production schedule, in such an
instance, may be
changed to produce more base models of the same vehicle model type (e.g., a
HondaTM AccordTM
DX). This change in the production schedule may necessitate a change in the
sub-assemblies
supplied to the primary assembly line 510. Further, it is not uncommon, due to
modern Just In Time
(JIT) production methods, for a single plant to fail to meet its production
schedule due to unforeseen
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defects, such as, for example, delays in receipt of parts at sub-assembly
lines 520, 540 or 550 from
the various parts suppliers. This defect may result in the inability for the
primary assembly line 510
being unable to manufacture the vehicles scheduled.
To address these further shortcomings and difficulties, the automotive
assembly process 500
incorporates communications system 600 illustrated schematically in Figure 6 -
an improvement of
the computer system 300 of the first embodiment illustrated in Figures 1-4.
Communications system
600 includes a plurality of local computer networks 601 A, 601 B, 601 C and
601 D (collectively
computer networks 601 ) in communication with each other through wide area
network 618.
Computer network 601 A includes host computer 604, computer server 606,
printers 610,
computer terminals 612 and PLCs 614 in communication over network backbone
602. Similar to
host computer 302 (Figure 3), server 606 is shown in communication with
computer software
medium 607. Computer software medium 607, which contains instructions and data
for server 606,
is readable by server 606. Computer software medium 607 may contain, for
example, database
software, computer applications, computer data, network software (including,
for example, wide area
networking software), data corresponding to the layout ofautomotive assembly
process 500 (Figure
5), or the like. While computer software medium 607 is illustrated as a
computer diskette, it could
equally be a tape, memory chip, or other removable or non-removable computer
readable medium.
Furthermore, the software medium may be a remote medium, such as a memory of a
remote
computer, and be downloaded over a suitable link such as over an network,
Internet, intranet,
dedicated data link, or the like.
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Connected to PLCs 614 are manufacturing equipment 616 which includes, but is
not limited
to, readers (such as bar code readers, and the like), robots (for welding, VIN
stamping, painting,
dispensing sealers, surfacers, fluid fillers, engine placement, quality
testing, glass placement, and the
like), conveyors, vehicle carriers, torque guns, computer terminals for data
input and output, repair and
inspection robots, and the like. PLCs 614 are typically assigned a unique
address on the network, such
as an IP address or the like. Consequently, the addition of new pieces of
equipment can be easily
facilitated by inserting a new PLC 614 into computer network 601A, assigning a
unique identifier or
address to the new PLC 614, and attaching the equipment 616 to the new PLC
614.
Bar code readers, such as a SmartEyeTM readers, are statically located at
various points on the
primary and sub-assembly lines. Data collected from these readers, which
includes the vehicle
identification number (VIN) and vehicle location, is transmitted from the
reader, which may be
connected to a PLC 614, over network backbone 602 and stored in database 608A
running on server
606. A redundant database, database 608B, is stored and hosted by host
computer 604. Database 608A
stores data about each particular vehicle including conventional build and
assembly sheets data. (fhe
build sheet, which is a computer record, includes instructions as to the
processes that need to be
performed to the assembly and the locations to which the assembly should be
transported. The build
sheet may be printed out and attached, either directly or indirectly, to the
particular assembly or sub-
assembly that is being manufactured. In contrast, the assembly sheet
identifies the various parts or
components that must be installed for the particular assembly or sub-assembly
to which the assembly
sheet is associated. Consequently, the assembly sheet identifies the parts
that are to be installed and
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the build sheet contains the instructions as to where and what processes are
to be used in putting the
parts identified on the assembly sheet together in order to manufacture the
assembly or sub-
assembly.)
Database 608A will also collect enhanced data corresponding to each vehicle's
progress
through the manufacturing process including: identified defects, painted body
storage status, vehicle
lot number, repairs performed, repairs required, physical position on assembly
line S00 as measured
over time, identification of the carrier (e.g., a conveyor hanger, underbody
carrier, or the like) upon
which a vehicle is transported throughout a plant or plants (which may change
over time), identification
of individual components installed on the vehicle, installation instructions
performed during assembly
(such as, for example, the torque settings used to install lug nuts, bolts,
etc.), and the like. Virtually
every part, process, inspection and repair detail about the manufacturing
process and the assemblies
and sub-assemblies manufactured is stored in databases 608A, 608B.
In addition to the above noted data that is keyed to specific assemblies or
sub-assemblies,
general data corresponding to the assembly process as a whole is also stored
in database 608A on server
606. This general assembly process data includes: inventory data, production
schedules, tool
(including robot) availability, quality results and the like. In an embodiment
of the invention, database
608A is used for the collection of production data, and determines routing of
assemblies or sub-
assemblies throughout the manufacturing process, while database 608B is a
replication of database
608A that is used for non-production related inquiries (such as those made by
management and
suppliers about production status) and backup purposes. Using database 608A
solely for
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manufacturing purposes assists the system's response time to database access
by limiting non-
production inquires and access to redundant database 608B. Database 608B may
be updated every few
seconds or minutes, as required. In the event that database 608A fails,
production access could
automatically be transferred to database 608B until such time as database 608A
is operating normally.
Databases 608A, 608B may be commercially available software such IBMTM
Universal DatabaseTM
(UDB), OracleTM database, or the like. Hereinafter, databases 608A and 608B
will be referred to
interchangeably and collectively as database 608.
PLCs 614, which may be those commercially available from suppliers such as
YaskawaTM,
MitsubishiTM, Allen BradleyTM, and others, enable communication from and to
the various pieces of
manufacturing equipment 616. Consequently, PLCs 614 enable data to be
transmitted from equipment
616 over network backbone 602 to, for example, server 606, and vice versa. As
a result, counter-
measures to adjust the production process, such as new robotic build
instructions (which may be in the
form of ladder logic instructions) can be transmitted from computer server 606
to the various pieces
of manufacturing equipment 616. Similarly, data on the performance of
equipment 616, such as
operations performed, equipment availability and the like, can be transmitted
from equipment 616,
through PLCs 614 over network backbone 602 to computer server 606.
Terminals 612 enable real-time input and output of data from line workers
(also referred to as
associates), management and other interested parties. For example, data
corresponding to defects
identified by an associate relating to a specific vehicle may be input into
terminals 612 by use of input
device, such as keyboard, touch screen, bar code reader, or the like. This
information would then be
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available to any other terminal or networked device (such as other terminals
612, plant displays, etc.)
for the display of data. The data so displayed may be summarised or collated
by computer server 606
in a variety of ways that are known in the art. Terminals 612 may access the
data on database 608
through custom software or via commercial software such as, for example, web-
browsers, such as
Internet ExplorerTM or NetscapeTM NavigatorTM.
Server 606 monitors and controls manufacturing network 602. Also, as indicated
previously,
server 606 hosts database 608A. Server 606 may be a conventional work station,
such as an IBMTM
RS/6000TM running AIXTM. Server 606 may also provide for data archiving and
redundant capacity
should there be a failure in host computer 604, and vice versa. If required,
server 606 may be several
individual computers providing the functionality described herein.
Host computer 604 may be a conventional mainframe or mini-computer such as,
for example,
an IBMTM S/390TM.
Local manufacturing networks 601 B, 601 C and 601 D, which may be located, for
example,
at the plants housing sub-assembly lines 520, 540 and 550, respectively, are
configured similar to
manufacturing network 601 A. Manufacturing networks 601 B, 601 C and 601 D may
not include
local databases similar to that of databases 608 of manufacturing network 601
A. Rather,
manufacturing networks 601 B-D may query, update and generally access database
608A by
communicating over wide area network 618. In an alternative embodiment, and in
an effort to
reduce bandwidth requirements over wide area network 618, database 608A of
network 601 A may
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be a master database, with a slave copy at each of local manufacturing
networks 601 B, 601 C and
601 D. In this latter embodiment, the local slave copies of database 608A
would be updated and
accessed by equipment and devices locally situated. The master and slave
databases of network
601 A - D would be synchronized periodically.
It should be noted that in addition to manufacturing networks 601 A-D of
communications
system 600, communications system 600 may also include computer terminals for
the input and/or
output of data at suppliers, shippers, dealers, and other parties involved in
the manufacture, sale and
maintenance of vehicles (or parts thereof) produced by primary assembly line
510 (which are not
shown in Figure 6).
Moreover, while each server 606 of networks 601 A-D may provide for control
and
maintenance for its respective network backbone 602, server 606 of network 601
A may additionally
provide centralized control of wide area network 618.
Printers 610 may be distributed throughout the manufacturing plant and may
provide for the
printing of ID Cards; tracking sheets; assembly sheets for the body, frame,
instrument panel, engine,
knuckles, and inspections cards; and inventory print-outs, and the like.
In operation, each assembly (such as, for example, an automobile) or sub-
assembly (such as,
for example, a rear-engine suspension) is assigned a unique identifier such as
Vehicle Identification
Number (VIN) in the former case or some other unique identifier in the latter
case. These unique
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identifiers are created as a first step in the manufacture of the assembly, or
sub-assembly as the case
may be. These identifiers are then stored in database 608A and used to track
the assembly (or sub-
assembly) throughout the entire manufacturing process. Moreover, each assembly
(or sub-assembly)
to be produced will be associated with a build sheet and an assembly sheet, as
described above.
Referencing Figure 7, along with Figures 5 and 6, in operation, information
detailing the
vehicles that need to be manufactured (based on customer orders) will be used
to establish a
production schedule. This production schedule may be determined by inputting
into a computer
(such as server 606 and database 608A of network 601A) the orders. The
computer may then
determine the parts required to build the vehicles ordered, determine parts
availability for these
vehicles (based on inventory records stored on database 608A), order more
parts (if required), etc.
The vehicles to be manufactured will then be broken down into sub-assemblies,
each of the sub-
assemblies being further broken down into further sub-assemblies and/or
individual components
(such as bolts, belts, fluids, etc.) which are required (i.e., the build and
assembly sheets for each
vehicle will be generated). Based on this information stored in computer
database 608A, a
production schedule is then established. The production schedule may also
group like vehicles (that
is, those vehicles that have similar assembly and build sheets) into groups or
lots. Each of the
vehicles in the production schedule will be assigned a unique identifier (such
as, for example, a VIN)
and a lot number. Each vehicle that is a member of the same lot of vehicles
will be assigned the
same lot number. Again, this information is stored in a database 608A (5702).
The production
schedule will then be broadcast to all of the locations required for the
manufacture of the vehicles
necessary to satisfy the customer orders (5704).
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Once the production schedule is broadcast to the various plants and suppliers
including the
plants housing sub-assembly lines 520, 540 and 550, production will commence
on the manufacture
of the various sub-assemblies with unique identifiers for each of these sub-
assemblies being
generated, assigned to the sub-assemblies, and associated with a vehicle's
unique identifier (such
as, for example, a VIN) in database 208. (S706). These unique identifiers will
be stored in database
608A of network 601 A.
Focussing on engine/front suspension (EFR) sub-assembly line 520, for
exemplary purposes
only, appropriate build and assembly sheets previously generated will be
associated with each unique
EFR sub-assembly (5708). It should be noted that the build and assembly sheets
for each sub-
assembly is simply a portion of the build and assembly sheets for the entire
vehicle. Each sub-
assembly will pass through the plurality of functional zones 570 (five, as
illustrated) that comprise
EFR sub-assembly line 520. In the functional assembly zone 582 of each
functional zone 570, parts
will be applied and processes performed in accordance with the build and
assembly sheets (5710).
The build and assembly sheets stored in database 608A are accessed by the
associates and/or robotic
equipment by querying database 608A. The query may be requested by PLCs 614,
in conjunction
with robotic equipment 616, and/or by computer terminals 612, both being
connected to network
backbone 602. The query, based on a sub-assembly's unique identifier, will be
transmitted over
network backbone 602. The query will be transmitted to server 606 of local
network 601 B where
it will be formatted for transmittal and transmitted over wide area network
618 to server 606 of
master network 601 A. In response to the query transmitted, database 608A will
return to the
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requesting party (the computer terminal 612 or PLC 614 of slave network 601 B
over wide area
network 618) a response such as, for example, the build and assembly sheets.
Based on the
operations performed and parts installed at functional assembly zone 582,
database 608A will be
updated by the transmission of this data over backbone 602 by PLCs 614, in
conjunction with
robotic equipment 616, and/or by computer terminals 612. This data may include
identifiers for the
parts installed, torque settings applied to various fasteners, welds
performed, etc. (5712).
Upon exiting the functional assembly zone 582, the sub-assembly will be
transported to, and
identified (by a SmartEyeTM reader, for example) at, the inspection/repair
zone 584 of the fimctional
zone 570 (5714). A variety of functional inspections will then be performed,
including, for example,
determining if all parts required have been installed, if the correct parts
have been installed, etc.
(5716). The identity of the sub-assembly, and the inspections completed and
the results obtained
from those inspections are then transmitted to database 608A, which is updated
accordingly (5718).
The sub-assembly is then transferred to the repair portion of the
inspection/repair zone 584. The
identity of the sub-assembly is determined again (by a SmartEyeTM reader, for
example) and a query
for the complete inspection results of the sub-assembly is transmitted to
database 608A (5720). T'he
complete inspection results will include all outstanding defects identified in
the current functional
zone 570 as well as those defects identified and not repaired upstream. Based
on the inspection
results, the time available and the repair capabilities at the present repair
area 584, some repairs may
be carried out and some defects rectified (5722). The defects rectified will
be transmitted to
database 608A so that it may be updated (5724). The EFR sub-assembly is then
transferred to the
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remaining functional zones 720 of EFR sub-assembly 520 (5726) where operations
5710-5724 will
be performed.
Upon completion of the manufacture of the EFR sub-assembly, the sub-assembly
is
packaged and shipped to primary assembly line 510 (S728). Included in the
shipping of the EFR
sub-assembly is the updating of database 608A with the required shipping
information (e.g., number
of sub-assemblies shipped, date of shipment, identity of the sub-assemblies,
identity of shipper, way
bill (or shipping) number, etc.). Upon arrival at primary assembly line 510,
the sub-assemblies are
transferred to line side proximate to the functional zone 570 that installs
the EFR sub-assembly to
the vehicle on primary assembly line 510 - shown by dotted arrows in Figure 5
(5730). The EFR
sub-assembly is then installed at this functional zone 570 (5732). If defects
are identified at the
inspection/repair zone 584 of the functional zone 570 installing the EFR sub-
assembly or any other
downstream functional zone 570 (5734), these defects are recorded in database
608A (5736).
Moreover, the identified defect (including the defect type, the identity of
the sub-assembly and,
possibly, a countermeasure) is broadcast to manufacturing network 601 B - the
local network of EFR
sub-assembly line 520. The defect message is broadcast by issuing a message
from server 606 of
master network 601 A, which transmits the message over wide area network 618
to sever 606 of slave
network 601 B. Slave network 601 B may then transmit the defect to all or some
of terminals 612 of
slave network 601 B located throughout the plant. As a result of this
broadcast message,
countermeasures to rectify the cause of the defect may be implemented on EFR
sub-assembly line
520.
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As mentioned above, the defect in the sub-assembly identified on primary
assembly line 510
may be, for example, delayed parts, missing components, parts not fitting
properly, incorrect parts
shipped, etc.
In the case of parts shortages or production schedule changes (which may be
caused, for
example, by other parts shortages, quality problems, or the like), a change to
the production schedule
may be broadcast to the sub-assembly lines affected, such as, for example, EFR
sub-assembly line
520. If, for example, a shipment of upgraded rear suspensions is delayed in
arnving at primary
assembly line 510 from rear suspension assembly line 550 due to a supplier
problem, this delay will
have been transmitted to database 608A of master network 601 A over wide area
network 618. As
a result of this delay, a message (such as a revised production schedule) may
be broadcast to EFR
sub-assembly line 520 requiring that production of upgraded EFR sub-assemblies
(which would have
been installed on vehicles having the upgraded rear suspension assembly) be
placed on hold and
production of base model EFR sub-assemblies be increased or ramped up.
Alternatively, the build
and assembly sheets for each of the unique identifiers being produced on the
EFR sub-assembly line
may be altered to include reference to only those components and operations
necessary to
manufacture base model EFR sub-assemblies. For example, the upgraded/luxury
EFR suspension
sub-assembly may differ only slightly from the base model EFR sub-assembly.
For example, the
upgrade EFR sub-assembly may have higher performance springs and shocks (or
dampers), as
compared to that of the base model EFR sub-assembly. In such an instance, it
may only be
necessary to alter the assembly sheet substituting (in the database records of
database 608A) the
higher performance springs and shocks with base model springs and shocks. As a
result of the
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electronic substitution in database 608A, when the sub-assemblies which have
had their assembly
sheets modified reach the functional zone 570 where the shocks and springs are
installed, the
assembly sheet accessed at this functional zone will include instructions to
install the base model
shocks and springs thereby effecting the change desired.
As will now be apparent, corrective counter-measures and real-time alterations
in build and
assembly sheets (instructions) can be made based on problems or defects
identified in other portions
of the assembly process. In either case, overall throughput of assembly line
500 is improved as the
impact of identified defects is reduced.
As a result of communications system 600 incorporating wide area network 618
and database
608A of master network 601A, the impact of defects that are identified in one
portion of the
assembly process may be reduced. Moreover, defects identified that may have an
impact on other
portions of the assembly line (including sub-assembly lines) can be remedied
and/or
countermeasures can be taken to reduce the impact on the overall production
process.
While the embodiment disclosed with reference to Figures 5, 6 and 7 discloses
a plurality
of sub-assembly lines feeding a primary assembly line, the invention may be
applied to a plurality
of sub-assembly lines that manufacture sub-assemblies which are not integrated
on a primary
assembly line. For example, a sub-assembly line at a first location may
produce a first sub-assembly
(such as. for example an automobile engine) for shipment to another location.
Similarly, a second
sub-assembly line, which may be at a second location, may produce a second sub-
assembly (such
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as, for example, a rear suspension), also for shipment. Nevertheless, the
first sub-assembly line,
which will be communication with the second sub-assembly line, may react to
defects (such as, for
example, delayed shipment of sub-assemblies) identified in the second sub-
assembly line, and vice
versa.
While the above embodiments have been described in conjunction with a computer
system
for entering and retrieving data corresponding to a vehicle, defects
identified, and repairs carned out,
the assembly line aforementioned could be implemented using a paper-based
system.
While more than one embodiment of this invention has been illustrated in the
accompanying
drawings and described above, it will be evident to those skilled in the art
that changes and
modifications may be made therein without departing from the essence of this
invention. All such
modifications or variations are believed to be within the sphere and scope of
the invention as defined
by the claims appended hereto.
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