Camera Lab 5
Manufacturing & Materials
Assembly Operations
Introduction: Manufacturing operations are often divided into two categories:
processing operations and assembly operations. This lab demonstration is
focused on assembly operations. Assembly can be accomplished in a variety of
ways. This lab demonstration will examine two common approaches: 1) the fixed
material location, and 2) the sequential assembly line.
If large, bulky products (aircraft, building air conditioning units) are being
assembled; the assembler(s), materials, and assembly fixtures are transported to
one location where the entire product is built without moving. This approach is
called a fixed material location assembly operation. Using this approach, the
assembler(s) are often very knowledgeable, to the degree that they could
assemble the entire product alone.
For smaller, more portable products, another method is the assembly line where
the product moves sequentially from one assembler to the next, and the
assemblers remain stationary. In the assembly line approach, the concept of
division of labor is used – every assembler becomes an expert at their particular
sub-assembly operation. Since not all assembly operations require exactly the
same amount of time, sequential assembly lines will have bottleneck operations activities that take longer than any of the other operations. Identifying and
eliminating bottleneck operations in assembly lines is a common problem
assigned to Industrial and Systems Engineers.
Activity: In this demonstration, we will set up and concurrently operate a fixed
material location assembly operation and a sequential assembly line operation.
Twelve students will be assigned as assemblers for each assembly operation (24
total). The remaining students will be the timers/data recorders.
In the fixed material location assembly operation, each of the 12 students will be
given a workspace and box containing all of the parts required to assemble an
entire camera. When the signal is given, each student will assemble the camera
and record the time required to complete their individual assembly operation.
Testing of the completed camera is included in the time for assembly. The
timers/data recording students assigned to this operation will assist in collecting
the time, recording the data on the white board at the front of the classroom, and
calculating the average, range, and standard deviation of the production rate
using the fixed material location approach.
While the data are being
summarized, the students that did the camera assembly will be asked to fully
disassemble the cameras and place the parts back in the boxes.
Camera Lab 5
Assembly Operations
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For the sequential assembly line operation, each of the 12 students will provided
a work space and a box containing a supply of the parts needed to complete their
sub-assembly operation. When the signal is given, the first student will perform
the first sub-assembly operation and immediately pass the camera to the second
student - and so on – until the camera is completely assembled and tested.
Each student will be asked to work as quickly and accurately as possible and
pass the camera on to the next person immediately. This approach is the
traditional “push” system sequential assembly line. The assembly line will be
halted when approximately 5 cameras have been completely assembled. The
timers/data recorder students assigned to this operation will assist in collecting
the average time required for each of the 12 operations, recording the data on
the white board at the front of the classroom. Also, the average, range, and
standard deviation of the overall production rate using the sequential assembly
line approach should be recorded. Students should also count the number of
partially completed cameras there are at each assembly station when the
production line is halted (work in process).
While the data are being
summarized, the students that did the camera assembly will be asked to fully
disassemble the cameras and place the parts in back their respective boxes.
Time permitting; the sequential assembly line demonstration will be conducted
again, but this time using a “pull” system approach using a “kanban” quantity of
one. The timers/data recorder students assigned to this operation should record
the same information as with the “push” system.
Analysis: Calculate and compare the mean and standard deviation production
rate for the assembly systems demonstrated.
What to submit for grading: Discuss some advantages and disadvantages when
comparing the fixed material location, “push”, and “pull” sequential assembly line
systems. Think in terms of production rate, system variability, work in process
(WIP), floor space requirements, bottlenecks, and identification of quality issues.
Camera Lab 5
Assembly Operations
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