manufacturing systems

Manufacturing Systems

Manufacturing System Design & Control


Facility Layout and Work Flow

Arrangement within a factory of:•Machines•Departments•Workstations•Storage areas•Aisles and common areas

Ensures a smooth flow of work, material, people and information through the system


3 three basic types of layout: •Process •Product •Fixed-Position

3 hybrid layouts: •Cellular •Flexible Manufacturing Systems•Mixed-model Assembly Lines

Manufacturing System Design Control

Process Layout:•Similar activities grouped together in work areas•Suitable for low volume or batch production•Flexible•Not very efficient•Storage space – large receiving, small shipping •Large aisles for movement of material

Lathe Department

Milling Department Drilling Department

Grinding Department Painting Department

Receiving and ShippingAssembly

L L

L L

L

L

L

L

M M M

G G G G

D D D D

D D D D

P

P

A A A


Product Layout:•Arrange activities in sequence of operation•Line set up for one product•Specialised machines•Suitable for mass production •More automated than process layouts•Efficient•Line flow – avoid bottlenecks •Not flexible

IN

OUT


Fixed Position Layout:•Large projects too big to move•Equipment and parts moved in and out of work area•Highly skilled workers - costly


Hybrid Layouts:Try to mix flexibility of process layout with efficiency of product layout

Cellular Layouts:

•Machines grouped into cells

•Cells process parts with similar features

•Work cell resembles a small assembly line (product)

•Layout between cells treated as process layout


4 6

5

1

2

11

9

8

7

1210

3

Raw Materials

Assembly

Processed based layout


Design of work cell

4

6

51

211

98

7

1210

3

Raw Materials

Assembly


Flexible Manufacturing Systems:

•Automates the entire manufacture of a product

•Very costly

•Complex software

•Small number of FMS worldwide

Flexible Manufacturing Cell:

•Smaller version of FMS

•One manufacturing process is automated


Progressive FMS:•All parts follow same progression through the work stations

•Best where group technology can be applied

Progressive FMS

Load StationUnload StationPallet


Closed Loop FMS:

•Larger variety of parts

•Parts can follow different paths

•Parts can skip stations

Closed Loop FMS

Pallet

UnloadLoad


Ladder FMS layout:•Parts moved to and from any machine in any sequence

•More flexible than progressive and closed loop systems Load/Unload


Mixed Model Assembly Lines:•More than one product is processed by the line

•Workers trained to work on more than one station

•Layout of line changed

•Long and short operations arranged to cancel each other

Traditional line

U Shaped Line

Capacity Management:•Demand for product can fluctuate over time

•Capacity < demand - Lose business

•Excess capacity: storage cost, labour cost etc.

•Capacity planning: match capacity to present and anticipated demand

Capacity Planning•Capacity Lead Strategy

•Capacity Lag Strategy

•Average Capacity Strategy



Capacity Lead Strategy

•Capacity expanded in anticipation of demand

•Expect to gain customers from competitors

Demand

Capacity

Qu

an

tity

Time


Capacity Lag Strategy

•Capacity increased after increased in demand

•Common where competition is weak

Demand

Capacity

Time

Qu

an

tity


Average Strategy Lag

•Capacity expanded to coincide with average expected demand

Demand

Capacity

Qu

an

tity

Time


How much to increase capacity?•100% capacity not efficient

•20% cushion is generally used

•20% capacity allows for unexpected demand

•Negative capacity can be used - Airlines

manufacturing systems

Documents