FLEXIBLE MANUFACTURING SYSTEMS (FMS)

BY - SHIVAM JOSHI

[0131ME114]

A flexible manufacturing

system is an automated

machine cell, consisting

of a group of processing

workstations,

interconnected with

automated material

handling and storage

system.

What is FMS ?

The issues such as reduction of inventories and market-response time to meet customer demands, flexibility to adapt to changes in the market, reducing the cost of products and services to grab more market shares, etc have made it almost obligatory to many firms to switch over to flexible manufacturing systems (FMSs) as a viable means to accomplish the above requirements while producing consistently good quality and cost effective products. FMS is actually an automated set of numerically controlled machine tools and material handling systems, capable of performing a wide range manufacturing operations with quick tooling and instruction changeovers.

• A flexible manufacturing system (FMS) is a highly automated GTmachine cell, consisting of a group or processing workstations (usuallyCNC machine tools), interconnected by an automated materialhandling and storage system, and controlled by a distributed computersystem.

• The FMS is most suited for themid-variety, mid-volumeproduction range

• The reason the FMS is called flexible is that it is capable of processinga variety of different part styles simultaneously at the variousworkstations, and the mix of part styles and quantities of productioncan be adjusted in response to changing demand patterns.

HOW FMS WORKS

Flexibility is an attribute that allows a mixed model manufacturing system to cope up with a certain level of variations in part or product style, without having any interruption in production due to changeovers between models. Flexibility measures the ability to adapt “to a wide range of possible environment”. To be flexible, a manufacturing system must posses the following capabilities

• Identification of the different production units to perform the correct operation

• Quick changeover of operating instructions to the computer controlled production machines

• Quick changeover of physical setups of fixtures, tools and other working units

The first FMS was patented in 1965 by Theo Williamson who

made numerically controlled equipment. Examples of

numerically controlled equipment are like a CNC lathes or mills

which is called varying types of FMS.

During the 1970s, with the ever-growing developments in the

field of technology, manufacturers started facing difficulties and

hence, FM systems became main-stream in manufacturing to

accommodate new changes whenever required. During the

1980s for the first time manufacturers had to take in

consideration efficiency, quality, and flexibility to stay in

business.

1. Workstations

2. Automated Material Handling and Storage systems

3. Computer Control System

4. Human Resources

• Following are the types of workstations typically found in an FMS:

1. Load/Unload Stations.

2. Machining Stations.

3. Other processing Stations.

4. Assembly Station.

5. Other Stations and Equipment.

Functions

1.Independent movement of workparts between stations.

2.Handle a variety of workpart configurations.

Temporary storage.

3.Convenient access for loading and unloading

workparts.

4.Compatible with computer control.

Material Handling Equipment

• Primary handling system establishes the basic layout of the FMS and isresponsible for moving workparts between stations in the system.(Conveyor)

• The FMS includes a distributed computer system that is interfaced to

the workstations,

Material handling system, and

Other hardware components.

• A typical FMS computer system consists of

a central computer and microcomputers.

• Microcomputers controlling the individual

machines and other components.

• The central computer coordinates the activities of the components toachieve smooth overall operation of the system

• Human are needed to manage the operations of the FMS. Functionstypically performed by human includes:

Loading raw workparts into the system,

Unloading finished parts (or assemblies) from the system,

Changing and setting tools,

Equipment maintenance and repair,

NC part programming in a machining system, and

Programming and operation the computer system.

Flexible manufacturing systems can be distingished according to thenumber of machines in the system. The following are typical categories:

1.Single machine cell (Type I A)

• A single machine cell consists of

one CNC machining center combined

witha parts storage system for

unattended operation.

• Completed parts are periodically unloaded from

the parts storage unit, and raw workparts are loaded into it

2. Flexible manufacturing cell (usually type II A)

• 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.

• A flexible manufacturing system has four or more processingworkstations connected mechanically by a common part handlingsystem and electronically by a distributed computer system.

Sequential FMS

Random FMS

Dedicated FMS

Engineered FMS

Progressive or Line

Type

Loop Type

Ladder Type

Open field type

Robot centered type

1.Progressive Layout

2. Loop Layout

3.Ladder Type Layout 4.Open Field Layout

5. Robot Centered Layout

1.External changes such as change in product design andproduction system.

2.Optimizing the manufacturing cycle time

3.Reduced production costs

4.Overcoming internal changes like breakdowns etc.5.Lower cost per unit produced

6.Greater labour productivity

7.Greater machine efficiency

8.Improved quality

9.Increased system reliability

10.Reduced parts inventories

11.To reduce set up and queue times

12.Improve efficiency

13.Reduce time for product completion

14.Utilize human workers better

15.Improve product routing

16.Produce a variety of Items under one roof

17.Improve product quality

18.Serve a variety of vendors simultaneously

19.Produce more product more quickly

20.Adaptability to CAD/CAM operations

21.Shorter lead times

1.Expensive.

2.Substantial pre-planning activity.

3.Cost to implement,

4.Substantial pre-planning

5.Requirement of skilled labour

6.Complicated system

CHALLENGES

1.Determining if FMS the best production system for

your company

2.Possible expansion costs associated with implementing

FMS

Metal-cutting machining

Metal forming

Assembly

Joining-welding (arc , spot), glueing

Surface treatment

Inspection

Testing

FMS is a revolution in the field of Manufacturing

Technology.

FMS can be designed to meet the specific demand of

each company

FMS is used for multitask operation.

FMS requires substantial investment of time and

resources.

T.Y