Manufacturing Systems Engineering

1. Course: Manufacturing Systems 2
CUPE 304
Topic: Flexible Manufacturing
Systems

2. Learning Objectives
By the end of the lecture students should be able to:
• Define Flexible Manufacturing Systems
• Identify components of a FMS
• Explain the different types of flexibility
• Solve an operational problem in FMS

3. Definition
 FMS consists of a group of processing
workstations interconnected by means of an
automated material handling and storage system
and controlled by integrated computer control
system.

4. Components of FMS
Workstations
• Load/Unload Stations; Machining Stations; Other
processing Stations- Punching, shearing, welding;
Assembly Station
• Material handling and storage
systems
• Primary handling system establishes the basic
layout of the FMS and is responsible for moving work
parts between stations in the system
• Secondary handling system consists of transfer
devices, automatic pallet changing, and similar
mechanisms located at the workstations
• Computer control system
• uses a distributed computer system that is
interfaced with all workstations in the system, as well
as with the material handling system and other
hardware components
1
2
3
4

5. Workstations
• Machining centres
• Load and unload stations
• Assembly workstations
• Inspection stations
• Forging stations
• Sheet metal processing, etc.

6. Automated Material Handling and
Storage system
• Random and independent movement of work
parts between workstations
• Handling of a variety of work part
• Temporary storage
• Convenient access for loading and unloading
of work parts
• Compatible with computer control

7. Computer Control System
• Control of each workstation
• Distribution of control instruction to
workstation
• Production control
• Shuttle control
• Work handling system and monitoring
• System performance monitoring and
reporting

8. The range of operations and part styles
Basic
Flexibilities
Machine flexibility
Material handling flexibility
Expansion flexibility
Product flexibility
Volume flexibility
System
Flexibilities
Program Flexibility
Production Flexibility
Aggregate
Flexibilities
Ability to transport different parts easily
Ability to produce parts in high and low
quantities
Ease with which the system can be
Expanded to increase total production
Ease with which new products can be
introduced
Ease of generating programs for new
machine sequences
The range or universe of part styles that
Can be produced on the system
Types and Tests of Manufacturing
Flexibility

9. Levels of flexibility
Dedicated FMS
• Designed to produce a limited variety of part
styles
• Complete universe of parts to be made on the
system is known in advance
Random-order
FMS
• Part family is large
• Substantial variations in part configurations
• New part designs introduced into the system and
engineering changes in parts currently produced

10. FMS in real life
• Employees at
Chrysler Group
LLC’
s Toluca
(Mexico) Assembly
Plant marry the
engine with the
body of an all-new
Fiat 500

11. Advantages of FMS
• Reduced work in process
• Increased machine
utilization
• Better management control
• Reduced direct and indirect
labor
• Reduced manufacturing
lead-time
• Consistent and better quality
• Reduced inventory
Disadvantages of FMS
• Expensive, costing millions
of dollars
• Substantial pre-planning
activity
• Limited ability to adapt to
changes in product
• Technological problems of
exact component positioning
and precise timing
necessary to process a
component.
• Benefit of employee
suggestion lost

12. How You Can Use FMS
• To reduce set up and queue times
• Improve efficiency
• Reduce time for product completion
• Utilize human workers better
• Improve product routing
• Produce a variety of Items under one roof
• Improve product quality
• Serve a variety of vendors simultaneously
• Produce more product more quickly

13. FMS Layouts
• Progressive Layout:
• Best for producing a variety of parts
• Closed Loop Layout:
• Parts can skip stations for flexibility
• Used for large part sizes
• Best for long process times

14. FMS Layouts Continued
• Ladder Layout:
• Parts can be sent to any machine in any sequence
• Parts not limited to part families
• Open Field Layout:
• Most complex FMS layout
• Includes several support stations

15. Operational Problem in FMS
• Problems can arise in manufacturing set up
when there are a few orders to be processed ,
and there are machines and tool combinations
to be considered.
• E.g Machine A Tool slots A1,A2,A3
• Machine B Tool slots B1,B2,B3

16. Example
Consider the set of parts shown in Table 1. (note the
two orders exist for part type a with different due
dates) Three machines of type A and one of type B
are available. Machines are setup once each day
and are normally available 12 hrs per day. Both
machine types can hold two tools. Determine the
parts to be produced in one day’s production.

17. Example
Unit Processing Time(hrs)
Part Type Order size Due Date Machine
type A
Machine Type B Tools
a 5 0 0.1 0.3 A1,B2
b 10 1 1.2 0.0 A2
c 25 1 0.7 0.4 A3,B4
d 10 1 0.1 0.2 A1,B2
e 4 2 0.3 0.2 A5,B3
a 10 4 0.3 0.2 A1,B2
Table 1: Part Data

18. Solution
-First consider constraints
-constraints available
• Due Dates
• Available Machine hours
• Available Tool slots

19. Solution cont………
• Consider the job with the earliest due date
first
• Available machine hrs
Machine A= 3machines x 12hrs
Machine B= 1 machine x 2hrs
Tool slots availability
Machine A = 2 slots x 3 machines
Machine B = 2slots x 1 machine

20. Solution cont…..
Time Assigned Tools Assigned
Step Assigned
Parts
A B A B
1 a 0.5 1.5 A1 B2
2 a, b 12.5 1.5 A1, A2 B2
3
4
5
5

21. Complete Solution
Time Assigned Tools Assigned
Step Assigned
Parts
A B A B
1 a 0.5 1.5 A1 B2
2 a, b 12.5 1.5 A1, A2 B2
3 a, b, c 30.0 11.5 A1, A2, A3 B2, B4
4 a, b, c, d
(2/10)
30.2 11.9 A1, A2, A3 B2, B4
5
6
Therefore, parts which can be produced in a 12hr production day
a,b,c and 2/10 of D

22. Practice Exercise
A machining operation requires bending, cutting and
welding operations. There are three bending machines,
one cutting machine and two welding machines available.
Each machine is available 8hrs per shift and there are two
shifts in a day. Each machine can hold two tool slots.
Table below shows the parts that are to be processed,
select the number of parts that can be processed in one
day [20]

23. Practice Exercise
Unit Processing Time(hrs)
Part Type Order size Due Date BENDING CUTTING WELDING tools
A 5 0 0.1 0.3 0.4 A1,B2
B 10 1 1.2 0.0 0.1 A2,B1
C 25 1 0.7 0.4 0.3 A3,B4
D 10 1 0.1 0.2 0.5 A1,B2
E 4 2 0.3 0.2 0.15 A5,B3
A 10 4 0.3 0.2 0.2 A1,B2

24. Conclusion
• FMS is an integrated system that is cable of
caring out several operations.
• Operational problems in FMS can be solved
considering the available constraints