| Overview
In this ALT, teams continue to practice the basic steps of DOE
by conducting and analyzing an L4 full factorial Jenga block experiment
with two predetermined factors and one two-factor interaction. These
steps, now increased to 13 and generalized to include the interaction
concept, are:
1. Identify the response variable.
2. Identify factors and levels.
3. Identify potential interactions to be analyzed.
4. Assign factors/interactions to array columns (L4 in
our case).
5. Decode the orthogonal array, making an execution array.
6. Conduct the actual experiment with replications.
7. Reconvert the orthogonal array to the analysis array.
8. Use the analysis array to perform an ANOVA.
9. Rank the factors/interactions in order of importance and as to
significance level.
10. Make a bar chart of factor coefficients and draw a factor/interaction
effect plot.
11. Use the analysis array to develop coefficients for the linear
model.
12. Formulate the linear model and determine the paper champion.
13. Perform a confirmation run for the paper champion if needed.
In this ALT, the factors/levels and the one interaction to be analyzed
are pre-established, eliminating the need for a team to perform
steps one through five above. In the real world, be aware that significant
attention must be paid to the first three steps in order to guarantee
a successful experiment. The first predetermined factor/level is
a two block slant of the platform (-1) and a level platform (1).
The second factor/level is the block platform alignment, parallel
(-1), perpendicular (1).
After completing this ALT, you should be able to demonstrate the
following competencies:
- Use sound sampling techniques and data analysis to make repeatable,
defensible inferences (Comp. 1).
- Solve real world problems by designing and conducting factorial
experiemenst (Comp. 2).
- Graphically display outcomes using simple graphical presentation
methods (Comp. 3).
- Use ANOVA to interpret experimental results (Comp. 4).
Materials and Equipment
No materials or equipment are needed to complete this ALT.
Safety and Disposal
No special safety or disposal procedures are required.
Pre-Activity
In this ALT, you analyze a 2-factor Design of
Experiment with replication that will address two factors and their
interaction using the Jenga Blocks. To prepare for the activity,
you work through an example problem using Excel.
Design of Experiments – Full Factorial Design
with replication
This exercise from Moen, Noland and Provost’s
book p. 163 is an example that looks at the effects of three factors:
(1) Booster Pressure, (2) Holding Pressure, and Screw Speed (3),
as part of a replicated study to minimize part shrinkage in an injection
molding process.
Click here
to access the example problem.
Click here to
download the solution.
Before completing the activity, download the L4 orthogonal array
worksheet and fill in the data from the ALT.
Click here
to download the file.
Activity
In your team, perform the following steps
to complete the activity:
- Refer to Instruction Sheet: Back to the Block Again and review
it carefully.
- With your team, complete Instruction Sheet: Back to the Block
Again.
Post-Activity
Your team should now post its results from the activity to the
Discussion Board.
Assignment
There are no instructions to prepare for ALT #4: How Changing Parameters
Affect Graph Location and Shape.
Assessment
Your facilitator may use Assessment Sheet: Back to the Block Again
to evaluate your results from the activity and your posting to the
Discussion Board.
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