An FMS is a highly automated manufacturing system consisting of CNC machine tools and an automated material handling system controlled by a distributed computer system. It is suited for mid-volume, mid-variety production between 5,000-75,000 parts per year. Advantages include increased efficiency and flexibility to process different part styles and respond to changing production needs. FMS can be classified based on the number of machines, level of flexibility, and type of operations performed.

2. FMS technology can be applied in the following
situations
The parts belong to a common product
The parts possess similar geometries
•The plant either
1.produces parts in batches
2.uses manned GT cells and management
wants to automate.

3. • The FMS is most suited for the mid-variety, mid-
volume production range

4. •The appropriate production volume range is 5000-
75,000 parts/yr.
• If annual production is below this range, an FMS is
likely to be an expensive alternative.
•If production volume is above this range, then
a more specialized production system should
probably be considered.

5. Advantages of FMS
• Increased machine utilization
• Fewer machines are required
• Reduction in factory floor space required
• Greater responsiveness to change
• Lower manufacturing lead times
• Reduced inventory requirements
• Reduced direct labour requirements and labour productivity
• Opportunity for unattended production

6. What is AN FMS ?
A Flexible manufacturing system (FMS) is a
highly automated GT machine cell, consisting
of a group of processing workstations (usually
CNC machine tools), interconnected by an
automated material handling and storage
system, and controlled by a distributed
computer system.

8. The reason the FMS is called flexible is that it is
capable of processing variety of different part styles
simultaneously at the various workstations, and the
styles and quantities of production can be adjusted in
response to changing demand patterns.

9. What Make It Flexible?
Three capabilities that a manufacturing system
must possess to be a flexible.
1.The ability to identify and distinguish among
the different part styles processed by the
system.
2.Quick changeover of operating instructions.
3.Quick changeover of physical setup.

10. AUTOMATED MANUFACTURING CELL WITH
TWO MACHINE TOOLS AND ROBOT

11. Four reasonable tests of flexibility in an automated
manufacturing system
•Part variety test:
•Can the system process different part styles in a non
batch mode?
•Schedule change test:
•Can the system readily accept changes in production
schedule and changes in either part mix or production
quantities?

12. •Can the system recover gracefully from equipment
malfunction and breakdowns, so that production is
not completely disrupted.
•New part test:
Can new part designs be introduced into the
existing product mix relative ease?
•Error recovery test:

13. • If the answer to all of these questions is “YES”
for a given manufacturing system, then the
system can be considered flexible.

14. TYPES OF FLEXIBILITIES
•Machine flexibility:
• Capability to adapt a given machine in the
system to a wide range of production
operations and part styles. The greater the
range of operations and part styles the greater
machine flexibility
•It depends on factors such as:
Skill and versatility of workers in the system
•Setup or change overtime. Ease of machine
programming
Tool storage capacity of the machine

15. •It depends on factors such as:
• The range of part styles that can be produced
on the system.
Production flexibility
• Machine flexibility of individual stations
• Range of Machine flexibility of all stations in
the system

16. Mix flexibility
• Ability to change the product mix while
maintaining the same total production quantity.
Producing the same parts only in different
proportions
•It depends on factors such as:
Similarity of parts in the mix
Machine flexibility

17. Product flexibility
Easy with which design changes can be
accommodated.
Easy with which new products can be
introduced
•It depends on factors such as:
Off line part program preparation
Machine flexibility

18. Routing flexibility
•It depends on factors such as:
Capacity to produce parts through alternative
work stations sequences in tool failures and
other interruptions at individual stations.
Similarity of parts in the mix
Similarity of workstations
Duplication of workstations
Common tooling

19. Volume flexibility
Ability to economically produce parts in high
and low total quantities of production
Level of manual labour performing production
Amount invested in capital equipment
•It depends on factors such as:

20. Expansion flexibility
Ease with which the system can be expanded to
increase total production quantities
•It depends on factors such as:
Expense of adding workstations
Ease with which layout can be expanded
Ease with which properly trained workers can be
added

21. Comparison of Four Criteria of Flexibility in a Manufacturing
System and the Seven Types of Flexibility

22. Flexible manufacturing systems can be classified
•Based on the kinds of operations they
perform:
• (1) processing operations
• (2) assembly operations.
• An FMS is usually designed to perform one or
the other but rarely both.

23. •According to machining systems:
Flexible machining systems will process
rotational parts or nonrotational parts.
Two other ways to classify FMSs are by:
• (1) number of machines and
•(2) level of flexibility.

24. Classification of FMS
• Flexible manufacturing systems can be
distinguished according to the number of
machines in the system. The following are
typical categories:
Single machine cell
Flexible manufacturing cell
Flexible manufacturing system

25. Single Machine Cell (SMC)
• A single machine cell consists of one
CNC machining center combined with
a parts storage system for unattended
operation.
• Completed parts are periodically
unloaded from the parts storage unit,
and raw work parts are loaded into it

27. It is capable of
(1) processing different styles
2.Responding to changes in production
schedule
3) Accepting new part introduction Criterion
4)Error recovery, cannot be satisfied because if
the single machine breaks down production
stops.

28. Flexible Manufacturing Cell
(FMC)
• A flexible manufacturing cell
consists of two or three processing
workstations (typically CNC
machining centers) plus a part
handling system.
• The part handling system is
connected to a load/unload station.

30. Flexible Manufacturing System (FMS)
• A flexible manufacturing system has four
or more processing workstations
connected mechanically by a common
part handling system and electronically
by a distributed computer system.

33. Level of Flexibility
• Another classification of FMS is according to
the level of flexibility designed into the
system.
• Two categories are distinguished here:
Dedicated FMS
Random-order FMS
• A dedicated FMS is designed to produce a
limited variety of part styles, and the
complete universe of parts to be made on
the system is known in advance.

34. • A random-order FMS is more appropriate
when
1.the part family is large,
2.there are substantial variations in part
configurations,
3.there will be new part designs
introduced into the system and
engineering changes in parts currently
produced, and
4. the production schedule is subjected to
change from day-to-day.

35. A comparison of dedicated and random-order
FMS types

36. Flexibility Criteria Applied to Dedicated FMS
and Random-order FMS

37. FMS Components
•Workstations
•Material handling and storage system
•Computer control-system.
•People required for managing and operating
the system.

39. Workstations
• Following are the types of workstations typically
found in an FMS:
1.Load/Unload Stations.
2.Machining Stations.
CNC machining center
Turning centers
Milling machine modules
Turning modules

40. Other processing Stations.
Punching, shearing, welding, etc.

41. Assembly:
Flexible automated assembly systems are being
developed to replace manual labor in the
assembly products typically made in batches.
Industrial robots are often used as the automated
workstations in these flexible assembly systems.
Other examples of flexible assembly workstations
are the programmable component placement
machines widely used in electronics assembly.

42. Other Stations and Equipment:
Inspection can be incorporated into an
FMS
Coordinate measuring machines
Special inspection probes
Machine vision

43. Stations for cleaning parts,
Pallet fixtures,
Central coolant delivery systems for the entire
FMS
Centralized chip removal systems

44. Material Handling and Storage System
Random, Independent movement of workparts
between stations.
Handle a variety of workpart configurations
Temporary storage
Convenient access for loading and unloading
workparts.
Compatible with computer control.

45. Material Handling Equipment:
1) a primary handling system
2) a secondary handling system.
The primary handling system establishes the
basic layout of the FMS and is responsible for
moving work parts between stations in the
system.

46. The secondary handling system consists of
transfer devices automatic pallet changers, and
similar mechanisms located at the workstations in
the FMS.
The secondary handling system include:
(1)reorientation of the work part if necessary to
present the surface that is to be processed
(1)buffer storage of parts to minimize work
change time and maximize station utilization.

47. Material handling system
• Automated fork lifting and Rail
traveler.

48. A 5 machines FMS for machining:-photo
courtesy of Cincinnati Milacron

49. FMS Layout Configurations:
1)in-line layout
2) loop layout
3)ladder layout
4)open field layout and
5)Robot-centered cell.

50. 1.In line Layout

51. 2. Loop Layout

52. 3.Ladder Type Layout

53. The ladder layout consists of a loop with rungs
between the straight sections of the loop.
The rungs increase the possible ways of getting
from one machine to the next, and remove the need
for a secondary handling system.
This reduces average travel distance and
minimizes overcrowded in the handling system,
thereby reducing transport time between workstations.

54. Open Field Layout

55. The open field layout consists of multiple loops and
ladders and may include sidings .
This layout type is generally appropriate for
processing a large family of parts.
The number of different machine types may be limited
and parts are routed to different workstations depending
on which one becomes available first.

56. Robot Centered Layout

57. The robot-centered cell uses one or more robots as
the material handling system.
Industrial robots can be equipped with grippers that
make them well suited for the handling of rotational
parts, and robot-centered FMS layouts are often used
to process cylindrical or disk-shaped parts.

58. Layout Configuration Typical Material Handling
System
In-line layout
Conveyor system
Rail guided vehicle system
Loop layout
Conveyor system
In-floor towline carts
Ladder layout
Conveyor system
Automated guided vehicle
system
Rail guided vehicle system
Open field layout
Automated guided vehicle
system
In-floor towline carts
Robot-Centered layout Industrial robot

59. Computer Control System
1. Workstation control.
The individual processing or assembly stations
generally operate under some form of computer control
For a machining system, CNC is used to control the
individual machine tools.

60. 2.Distribution of control instructions to workstations.
In a machining FMS, the DNC system stores the
programs, allows submission of new programs
and editing of existing programs as needed.

61. 3. Production control:
Input data required for production control includes
desired daily production rates per part, numbers of
raw work parts available and number of applicable
pallets.
The production control function is accomplished by
routing an applicable pallet to the load/unload area
and providing instructions to the operator for loading
the desired work part.

62. 4. Traffic control
This refers to the management of the primary
material handling system that moves work parts
between stations.
Traffic control is accomplished by actuating
switches at branches and merging points,
stopping parts at machine tool transfer locations,
and moving pallets to load/unload stations.

63. 5. Shuttle Control
This control function is concerned with the
operation and control of the secondary handling
system at each workstation.
Each shuttle must be coordinated with the
primary handling system and synchronized with
the operation of the machine

64. 6. Work Piece Monitoring
The computer must monitor the status of each
cart and pallet in the primary and secondary
handling systems as well as the status of each of
the various work piece types.

65. 7. Tool control
Tool location:
This involves keeping track of the cutting tools at
each work station.
If one or more tools required to process a
particular work piece is not present at the station
that is specified in the part's routing.

66. The tool control subsystem takes one or both of
the following actions:
(a)determines whether an alternative
workstation that has the required tool is
available .
(a)notifies the operator responsible for tooling in
the system that the tool storage unit at the
station must be loaded with cutter(s).

67. Monitoring
A tool life is specified to the computer for each
cutting tool in the FMS.
A record of the machining time usage is
maintained for each of the tools, and when the
cumulative machining time reaches the
specified life of the tool.
The operator is notified that a tool replacement
is needed

68. 8. Performance Monitoring and Reporting
The computer control system is programmed to
collect data on the operation and performance
of the FMS.
This data is periodically summarized, and
reports are prepared for management on
system performance

69. 9. Diagnostics:
This function is available to a greater or lesser
degree on many manufacturing systems to
indicate the probable source of the problem
when a malfunction occurs.
It can also be used to plan preventive
maintenance in the system and to identify
impending failures.

70. The purpose of the diagnostics function is to
reduce breakdowns and downtime and
increase availability of the system

71. Allied Signal’s Flexible Manufacturing System

72. Human Resources
• Human are needed to manage the operations
of the FMS.
• Functions typically performed by human
includes:
Loading raw workparts into the system
Unloading finished parts (or assemblies)
from the system

73. Changing and setting tools
Equipment maintenance and repair
NC part programming in a machining
system
Programming and operation the computer
system.

74.  Metal-cutting machining
 Metal forming
 Assembly
 Joining-welding (arc , spot), gluing
 Surface treatment
 Inspection
 Testing

75. FMS Benefits
Increased machine utilization:
FMSs achieve a higher average utilization than
machines in a conventional batch production
machine shop.
Reasons for this include:
(1)24 hr/day operation
(2)Automatic tool changing at machine tools
(3)Automatic pallet changing at workstations

76. Fewer machines required
Reduction in factory floor space required
Because of higher machine utilization, fewer
machines are required.
Reductions in floor space requirements are
estimated to be 40-50%

77. Greater responsiveness to change
An FMS improves response capability to part
design changes, introduction of new parts,
changes in production schedule and product mix,
machine breakdowns, and cutting tool failures.
Adjustments can be made in the production
schedule from one day to the next to respond to
rush orders and special customer requests.

78. Reduced inventory requirements
Because different parts are processed together
rather than separately in batches, work-in-
process (WIP) is less than in a batch production
mode.
The inventory of starting and finished parts can
be reduced as well. Inventory reductions of 60-
80% are estimated.

79. Lower manufacturing lead times
Reduced direct labor requirements and higher labor
productivity
Closely correlated with reduced WIP is the time
spent in process by the parts. This means faster
customer deliveries
Higher production rates and lower reliance on
direct labor translate to greater productivity per
labor hour with an FMS than with conventional
production methods. Labor savings of 30-50%
are estimated

80. Opportunity for unattended production:
The high level of automation in an FMS allows it to
operate for extended periods of time without human
attention.
In the most optimistic scenario, parts and tools are
loaded into the system at the end of the day shift, and
the FMS continues to operate throughout the night so
that the finished parts can be, unloaded the next
morning.