2. A flexible manufacturing system (FMS) is a set of
numerically controlled machine tools and supporting
workstations connected by an automated material handling
system and all aspects of the system controlled by a central
computer
FMS is distinguished from an automated production line by its
ability to process more than one product style simultaneously.
At any moment, each machine in the system may be
processing a different part type.
FMS can let us make changes in production schedule in order
to meet the demands on different products.
5. FMS systems are intended to solve the following problems:
Reduced cycle times
Lower work-in-process (WIP) inventory
Low direct labour costs
Ability to change over to different parts quickly
Improved quality of product (due to consistency)
Higher utilization of equipment and resources
Quicker response to market changes
Reduced space requirements
Ability to optimize loading and throughput of machines
Expandability for additional processes or added capacity
Reduced number of tools and machines required
Motivation for designers to add variations and features to meet
customer requirements.
Compatible with CIM
6. Expensive
Substantial pre-planning activity
Sophisticated manufacturing systems
Technological problems of exact component
positioning and precise timing necessary to process a
component.
7. Four models:
Deterministic models-
• models that are used to gain starting estimations of system
performance, but not for complex phenomena (don’t include operating
characteristics, including queues, that may degrade performance, thus
are a little optimistic)
Queuing models-
• Based on mathematical Queuing theory
• Better estimation of system parameters including more dynamics
• They examine various simple system configurations
• Characteristics handled here include layout configuration, number of
pallets in the system, and production scheduling rules
• Example- CAN-Q model
8. Discrete event simulation-
• Based on computer simulation techniques
• Most accurate estimation of system parameters
• Characteristics handled here include layout configuration, number of
pallets in the system, and production scheduling rules
Other approaches-
This is a hold-all title that includes various approaches, from
mathematical programming, heuristic approaches, and a number of
operational research techniques.
9. Following are some approaches which should be considered in order to
optimize the overall efficiency and effectiveness of FMS:
1. Minimizing the process cycle time: The process must be designed
to minimize machining and handling.
2. Maximizing the utilization of each machine: This can be done by
balancing the work load in the system and real time scheduling
3. Use of automated storage systems to keep work ready for
machines to process: The raw work parts must be replenished as
and when needed to avoid starving the work centres.
10. 4. Provision of adequate sensors for the detection of errors or
problems: This includes the detection of the presence and absence
of parts, jamming, tool wear, machine failures, and so on.. This can be
done with the use of vision systems, limit switches, proximity
switches, tool monitoring system, etc
5. Backup capabilities: The system should be able to run even when
failures occur
6. Incorporation of in-process or post-process measurement and
inspection techniques: These assure product quality and reduce
scrap and rework
7. Use of identification marking techniques: Bar codes and RFID tags
are now popular for identifying products as well as components. This
permits automatic tracking of workpieces and tools
11. Through the use of reprogrammable tooling in the body shop, standardized equipment in the
paint shop and common build sequence in final assembly, Ford can build multiple models on
one or more platforms in one plant.
In the body shop, where
the sheet metal comes
together to form the
vehicle’s body, flexibility
means more than 80
percent of the tooling is
not specific to one model.
It can be reprogrammed to
weld a car or a truck or a
crossover of similar size.
Body Shop
In the paint shop, flexibility
means robotic applicators
are programmed to cover
various body styles – as
they move through the
paint booth – with equal
precision. This results in
minimizing waste and
environmental impact
while maximizing quality.
Paint Shop
In the final assembly
area, flexibility means
the build sequence is the
same among multiple
models on one or more
platforms allowing for
efficient utilization of
people and equipment.
Final Assembly
