Design Of Experiment (DOE)
- nsyirah04
- Jan 21, 2023
- 4 min read
Hey therešš»š! Welcome back to my blog. It's been quite a while since I wrote my last blog due to the school holidays but I am back and ready to share with you what I learned in week 13š. In week 13, I learned about the Design of Experiments (DOE). š©āšØšš
What is DOE? š¤
A statistics-based approach to designing experiments.
A methodology to obtain knowledge of a complex, multi-variable process with the fewest trials possible.
Optimization of the experimental process itself.
The backbone of any product design as well as any process/ product improvement efforts.
CASE STUDYšµļøāāļø
What could be simpler than making microwave popcornšæ? Unfortunately, as everyone who has ever made popcorn knows, itās nearly impossible to get every kernel of corn to pop. Often a considerable number of inedible ābulletsā (un-popped kernels) remain at the bottom of the bag. What causes this loss of popcorn yield? In this case study, three factors were identified:
1. Diameter of bowls to contain the corn, 10 cm, and 15 cm
2. Microwaving time, 4 minutes and 6 minutes
3. Power setting of microwave, 75%, and 100%
8 runs were performed with 100 grams of corn used in every experiment and the measured variable is the amount of ābulletsā formed in grams and the data collected are shown below:
Factor A= diameter š
Factor B= microwaving time š°ļø
Factor C= power šŖš»
Full factorial
Significant of factors:
When the diameter increases from 10cm to 15cm, the amount of bullets formed decreases from 1.70g to 1.55g.
When the microwaving time increase from 4 minutes to 6 minutes, the amount of bullets formed decreases from 2.07g to 1.18g.
When the power increase from 75% to 100%, the amount of bullets formed decreases from 2.63g to 0.62g.
Therefore the most significant factor that affects the number of bullets formed is C (power).
INTERACTIONS:
The gradient of both lines is different (one is + and the other is -). Therefore thereās a significant interaction between A and B.
The gradient of both lines are different (one is + and the other is -). Therefore thereās a significant interaction between A and C.
The gradient of both lines is different by a little margin. Therefore thereās an interaction between B and C, but the interaction is small.
In conclusion from this data analysis, to maximize the number of bullets formed, we have to use a diameter of 15cm, microwaving time of 4 seconds, and power of 75%.
FRACTIONAL FACTORIAL
When the diameter increases from 10cm to 15cm, the amount of bullets formed increases from 1.6g to 1.9g.
When the microwaving time increase from 4 minutes to 6 minutes, the amount of bullets formed decreases from 2.1g to 1.4g.
When the power increase from 75% to 100%, the amount of bullets formed decreases from 2.97g to 0.53g.
Therefore the most significant factor that affects the number of bullets formed is C (power).
Interaction:
The gradient of both lines are different (one is + and the other is -). Therefore thereās a significant interaction between A and B
The gradient of both lines are different (one is + and the other is -). Therefore thereās a significant interaction between A and C
The gradient of both lines are different by a little margin. Therefore thereās an interaction between B and C, but the interaction is small.
In conclusion from this data analysis, to maximize the number of bullets formed, we have to use a diameter of 15cm, microwaving time of 4 seconds, and a power of 75%. Hence, this result is the same as the full factorial
The excel sheet can be found below:
Learning Reflection: This practical was definitely a fun one with lots of interactions and laughter in my class, especially during the group activitiesš¤£! When I first read the practical package I thought that it was going to be such a tedious process since we had to collect so many data, both full and half factorialš®āšØ. However, to my surprise, my group took a shorter time to complete it than what I expectedšš». During the tutorial lesson, I was a bit confused about how this factorial thing works and how I can make sense of it since all I see are so many numbersš©. Additionally, I hateeeee using excel and this activity requires me to use it so urghhhš¤¢. However, during the practical, I then realized the logic of this "factorial theory" and wondered that whoever created this method of data analysis is just a genius, the fact that he could come up with this method is just beyond wordsš¤Æš¤Æš¤Æ. This practical also has helped me improve my excel skills and its so much easier to use now after all this data analysisš· so i dont hate it that much anymore hehe š . Itwas a fun practical session with my group, asraf was incharge of the data recording, i helped with the launching of the ball, eshvin and valarie helped with the measurement of the data. The pictures and video below shows the process of it and also during the group activity.
During the group activity, the task was to shoot down the target (our lectures) using our own launcherāļøšÆ. This is where we were given the chance to apply our knowledgešš©āš«. We had to choose the correct parameters to use by looking at our data sheet from the practical. After looking at our datasheet, we decided that it's best to use the longer arm length, lighter projectile weight, and stop angle of 120 degrees. After completing the activity, I learned that this method of data analysis is very effective in determining the best design for the experiment. At the end of the activity, my group came in 2nd place woohooš„š„³, not that bad rightttt, 8 marks in the bagš¤©
I have come to the end of my blog, hope you guys enjoyed it and stay tuned for the next bloggg bye bye!š¤šš»āš»
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