Page 112 - DMGT501_OPERATIONS_MANAGEMENT

Operations Management

Notes 4.6.1 Defining the Layout Problem

The layout-planning problem for assembly lines is to determine the minimum number of
stations (workers) and assign tasks to each station, so that a desired level of output is achieved.
The design must consider the following aspects:
1. It should focus on achieving a desired level of output capacity.
2. The tasks assigned to stations and the sequence in which tasks must be carried out.
3. The output should be attained efficiently, without using minimum input resources.

Table 4.3: Assembly Line for Contact Breaker

Preceding Task
Work Predecessor Time/Unit Operators
Station Work Task Assigned Task per station
Station (Hours)
A: Contact Breaker
Assembly; Take
1 - None 0.010 1
Molding Half and clean
burrs etc.
B: Install contacts
A 0.020
C: Install Springs
2 1 B 0.020 2
D: Install plastic levers
A,C 0.040
etc. on Molding Half.
E: Install contacts
A 0.020
F: Install Springs
3 1 B 0.020 2
G: Install plastic levers A,C 0.040
etc., on Molding Half.
H: Close with other G
4 2,3 0.050 2
Molding Half
I: Assemble 4 of the H 0.008
5 4 1
above units
6 5 J: Insert Rivets I 0.040 1
K: Rivet the sandwich
7 6 J 0.098 1
units
L: Switching Test under
8 7 E 0.050 1
load
M: Pack Contact
9 8 F 0.020 1
Breaker unit
Total 0. 354

How this is achieved can be best understood with an example. ABC Electricals is a medium-
sized firm in Delhi. It has an established design of a contact breaker assembly, used industry-
wide to protect all electrical circuits. The company has established an assembly line to manufacture
the product.

The operator starts the assembly process with a molding half. Into this molding he puts the
contacts, springs, plastic levers, etc. The assembly is closed off with a similar molding half. The
final assembly, comprised up to four of these units, is secured with four rivets passing through
the sandwich. The assembly is then tested. Testing is a critical operation, as the contact breaker
assembly carries up to 415 volts. If the unit is found acceptable, it is labeled and packed for
dispatch.

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