Flexible Manufacturing System (FMS)

Flexibilities

Machine Flexibility

- Ease with which a machine can perform various operations with little time to switchover from one to another.

Material Handling Flexibility

- Ease with which parts can be transported from one machine to another with little travel time.

Operation Flexibility

- Ease with which alternate operations sequences can be used for processing a part with little change in time.

Flexibilities

Volume Flexibility

- Measure of system’s capability to adjust varying volumes and still being profitable.

Expansion Flexibility

- Measure system’s ability to be built and expanded with little investment.

Routing Flexibility

- Measure of alternate paths which a part can follow through a system for complete manufacturing.

Flexibilities

Process Flexibility

- Measure of system’s capability to process variety of different parts without any change in set up.

Product Flexibility

- Measure system’s capability to process variety of different parts with minimal set up.

Program Flexibility

- Measure the times to which the system can run unattended.

Flexibilities

Production Flexibility

- Measure of system’s capability to switchover another class of parts with little investment.

Market Flexibility

- Ability of a system to adapt to changing market conditions.

FMS Cell Formation

FMS Cell Formation

FMS Cell Formation

FMS Cell Formation

FMS Cell Formation

FMS Cell Formation

FMS Cell Formation

FMS Cell Formation

FMS Cell Formation

FMS Cell Formation

FMS Cell Formation

FMS Cell Formation

FMS Part Allocation

Eight parts are being considered for an FMS cell. These parts are currently purchased from vendor. The cell will be available for 250 hours period. The table below gives current unit cost for each part type, raw material cost, demand rate and unit production time. The cell is charged at the rate of $50 /hour which includes all related expenses. Which parts should be added to the FMS cell.

Part Type 1 2 3 4 5 6 7 8

Unit purchase price 200 155 300 125 300 86 93 165Material cost 45 35 124 50 120 34 36 114Demand 100 50 50 75 60 30 50 600Processing time/unit 1.0 2.0 4.0 1.0 2.0 1.0 1.0 0.5

Unit Savings 105 20 -24 25 60 2 7 26Hours 100 100 200 75 120 30 50 300Savings 105 10 ---- 25 30 2 7 ----

Objective Function: Maximize

Part Allocation: Knapsack Problem

n

iii xp

1

n

iii Wxw

1

Subject to

Total Time = 16 hours

Part Time (min) Value (Rs)

1 110 7000

2 210 11000

3 150 12000

4 320 16000

5 280 10000

6 510 24000

7 390 17000

8 460 18000

FMS Part Assignment

Consider the set of parts shown in table below. Three machines of type A and one machine of type B are available. Machines are set up once each day and are normally available for 12 hours per day. Both machines are capable of holding two tools. The initial letter in the tool name indicates the machine required. What should be produced today.

Unit Processing TimePart Type Order Size Due date Machine A Machine 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

FMS Part Assignment

Unit Processing TimePart Type Order Size Due date Machine A Machine 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

Step Assigned Parts Time Assigned Tools Assigned

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