Unit iv Shop floor control and FMS

ME 2402 – COMPUTER INTEGRATED

MANUFACTURING (CIM)

YEAR/SEMESTER : IV/VII

UNIT IV SHOP FLOOR CONTROL AND

INTRODUCTION TO FMS

Prepared By

MANIMARAN.M

ASSISTANT PROFESSOR

K.RAMAKRISHNAN COLLEGE OF ENGINEERING

TRICHY

1/25/2016 1 M.MANIMARAN KRCE TRICHY

UNIT IV SHOP FLOOR CONTROL AND INTRODUCTION TO

FMS

Shop floor control – phases – factory data collection

system – automatic identification methods – Bar code

technology – automated data collection system. FMS –

components of FMS – types – FMS workstation – material

handling and storage system –FMS layout- computer

control systems – applications and benefits.

1/25/2016 M.MANIMARAN KRCE TRICHY 2

SHOP FLOOR CONTROL

A shop floor control system is defined as a system for utilizing

data from as well as data processing files to maintain and

communicate information on shop orders and work centers. It

also known as Production Activity Control (PAC).


Function of SFC

Scheduling

Dispatching

Follow-up

Providing output data

Providing efficiency


Phases of SFC

1. Order release

phase provides the documentation needed to process a production

order through the factory.

The collection of document is called as shop packet.

Route sheet

Material requisitions

Job cards

Move tickets

Part list


Phases of SFC 2. Order scheduling

order scheduling executes the dispatching function in production planning and control.

Two elements of order scheduling

• Machine loading

• Job sequencing

Priority sequencing rules (or)Dispatching rules

SOT (shortest operating time)

Earliest due date

STR (slack time remaining) = time remaining before due date-remaining process time

STR/OP = STR/No.of. Remaining operations

Critical ratio (CR) = Due date – Current date/No.of remaining working days

Queue ratio (QR) = slack time remaining in the schedule /planned remaining queue time

First – come, first served

Last – come, last served


Phases of SFC

3. Order progress

The order progress phase monitors the status of the various orders

in the plant, work-in-progress and other characteristics that

indicate the progress and performance of production.

Three forms of order progress report as follow as

Work order status report

Progress report

Exception report


Factory data collection system

Several data collection techniques used to collect data from the shop floor. These techniques require the employees to gather the data and later the data are gathered on a fully automated systems that requires no human participation.

Types of data collected by FDC

– List number of parts that are scraped

– List number of parts requiring rework

– Equipment downtime

– Time clock by employees for punch in and out.

– Time taken at each work Centre

– Labor time in each work order

Factory data collection system


Types of data collection system

1. On-line data collection system

The data are entered directly into the plant computer system

and are immediately available to the order progress

2. Off-line data collection system

the data are collected temporarily in a storage device to be

entered and processed by plant computer in a batch mode


Automatic identification method

It refers to various technologies used in automatic (or) semi-

automatic acquisition of product data entry into a computer

system.

Basic components

• Encoded data

•Machine reader (or) scanner

• Decoder


Types of Automated Identification Technology

Bar codes

Radio frequency systems

Magnetic stripe

Optical character recognition

Machine vision


Application

1. Material handling

– Shipping and receiving and Storage

– Sortation

– Order picking

– Parts for assembly

2. Manufacturing

– Order processing

– Work-in-process

– Machine utilization and Worker attendance

3. Retails sales and inventory

4. Ware housing and distribution center operations

5. Mail and parcel handling

6. Patient identification in hospitals

7. Cheque processing in banks


BAR CODE TECHNOLOGY

• It is most the most popular method of automatic identification

in factory data collection.

• Bar code technology was invented in 1949 by Norman J.

Woodland and Bernard silver of USA.


BAR CODES TECHNOLOGY


Bar codes technology Commonly used bar codes are:

Code 39 interleaved two-of-five(ITF)

Universal product code code 93

Code 128 Codabar


Radio frequency identification


AUTOMATED DATA COLLECTION SYSTEM

Computer process monitoring involves the use of the computer

to observe the process and associated equipment and to collect

and record data from the operation.

• Data acquisition system

• Data collection system

• Multi level scanning


Flexible manufacturing system

DEFINITION

• FMS is highly automated GT Machine cell, consisting of group of

processing stations interconnected by automated material handling

system and controlled by computer system.

• or

• A flexible manufacturing system (FMS) is a form of flexible automation

in which several machine tools are linked together by a material-

handling system, and all aspects of the system are controlled by a central

computer.


TYPES OF FLEXIBILITY

There are three levels of manufacturing flexibility.

a) Basic flexibilities

1.Machine flexibility: The ease with which a machine can process various

operations

2.Material handling flexibility: A measure of the ease with which different part

types can be transported and properly positioned at the various machine tools in a

system

3.Operation flexibility: A measure of the ease with which alternative operation

sequences can be used for processing a part type


b) System flexibilities

1.Volume flexibility

2.Expansion flexibility

3.Routing flexibility

4.Process flexibility

5.Product flexibility

c) Aggregate flexibilities

1.Program Flexibility

2.Production Flexibility

3.Market Flexibility


TESTS OF FLEXIBILITY

The following are 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 quantity.

Error recovery test. Can the system recover quickly from equipment breakdowns, so that the production is not completely disrupted.

New part test. Can new part designs be introduced into the existing product mix with relative ease.


COMPONENTS OF FMS

FMS has the following components.

Workstation

Material Handling and Storage System

Computer Control System

Human Resources


WORKSTATION

Following are the types of workstations typically found in an FMS

1. Load/Unload Stations.

2. Machining Stations.

3. Other processing Stations. (punching, shearing, welding,

etc.)

4. Assembly Station.

5. Inspection station.

6. Other Stations and Equipment. (Inspection, Vision, etc)


MATERIAL HANDLING SYSTEM

The various automated material handling systems are used to

transport work parts and subassembly parts between the

processing stations.

Functions:

1. Random, Independent movement of work piece between

stations.

2. Handle variety of Parts

3. Temporary storage

4. Convenient access for loading and unloading

5. Compatible with computer control.


COMPUTER CONTROL SYSTEM

1. Production Control

2. Workstation Control

3. Quality Control

4. Failure diagnosis

5. Safety Monitoring

6. Work piece Monitoring

7. Performance Monitoring and Reporting


HUMAN RESOURCES

Human are needed to manage the operations of the FMS.

Functions typically performed by human includes:

1. Loading raw work parts into the system,

2. Unloading finished parts (or assemblies) from the system,

3. Changing and setting tools,

4. Equipment maintenance and repair,

5. NC part programming in a machining system, and

6. Programming and operation the computer system.


FMS LAYOUT CONFIGURATION

These are different types of layout:

1. Inline or progressive layout

2. Loop Layout

3. Ladder Layout

4. Open-field Layout

5. Robot Centered Layout


INLINE LAYOUT


Loop Layout


LADDER LAYOUT


TYPES OF MATERIAL HANDLING SYSTEM

1. Conveyor

2. Cranes and Hoists

3. Industrial Trucks

4. Monorails

5. AGV’s 6. Industrial Robots


Conveyor


Cranes


Hoists


Trucks


RGV and AGV


FMS APPLICATION

1. Machining

2. Sheet metal working

3. Plastic Injection Moulding

4. Forging

5. Welding

6. Textile Machinery manufacture

7. Semiconductor Manufacture


ADVANTAGE OF FMS

1. Increased machine utilization

2. Reduced Inventory

3. Reduced Lead times

4. Greater Flexibility in production scheduling

5. Reduced direct labor cost

6. Increased Labor productivity

7. Consistent quality


DISADVANTAGES OF FMS

1. High Capital Investment is required

2. Training and Maintaining knowledge labor is difficult

3. Cost of Fixture

4. Conditioning Monitoring is expensive

5. Sophisticated manufacturing systems

6. Limited ability to adapt to changes in product or product mix.


THANK YOU!!


Engineering

Unit iv Shop floor control and FMS