I'm trying to design an experiment. I want to vary Pressure and temperature at two levels (high and low) and measure the effect on quality and flowrate.
I'm new to DOE and from my research I need to do a 2x2 full factorial design giving a total of 4 tests to run.
The literature mentions replication sets (where I do all 4 tests again) and center points (where i do 4 tests between the original tests). But how do I know how many replication sets I need to do? and whether center points are necessary.
I want to be able to report my repeatability but I thought this requires test being repeated at least 3 times to determine the variance etc.
Am I correct in saying that an ANOVA test is what will 'quantify' the effect of pressure/temperature on the quality and flowrate? and is a 2-way ANOVA the correct choice?
----- EDIT ----
- This is a laboratory experiment and the effect of environment and other variables is minimal.
- I have randomised the order in which my runs are done to try minimise the effect of random error and noise on the experiments
- each experiment takes roughly 5 hours, I can do one per day
- I have planned to do center points as a check for linearity.
- my ultimate goal is to determine the effect that temperature and pressure have on the quality and flowrate and then suggest an operating point (Temp/pressure combination) which is the best.
- thus far I have only completed the 2x2 base case tests.
- Ive noticed that both temperature and pressure have significant effects.
- I repeated a single one of those tests and the results were very similar