Dear @statman, 1) yes this is what I am doing for the district factor min= 1 and max = 3 2) okay I will do this  my data are attached  thank you in advance               ... View more

Thank you, - Are all of the factors continuous? 3 continuous and 1 Discrete Numeric 3 levels factor - What is the model you are predicting? I want to perform a screening design, main effect, and 2 order interactions For the day to day variations, I do not know if I will have a variation or not. The situation is that I have one hard to change factor that can not change levels easily and I will accept any solution to keep it fixed for a certain level of runs. When I did some preliminary experiment I found that the variation coming from the Whole plot has a negative value and I do not know how to explain this ? bets regrds ... View more

Dear Sir, Following your answer, how I can do a sequential experiment since I have 9 factors which is too much? Is not better to start with a main effect screening (PB) and then sequential experimentation using CCD? many thanks ... View more

Dear Sir, Following your answer, how I can do a sequential experiment since I have 9 factors which is too much? Is not better to start with a main effect screening(PB) than a sequential experimentation using CCD? many thanks ... View more

Thank you for all the informations ... View more

many thanks ... View more

Thank you for your answer. This is my first experience with DoE therefore I will need further details. As I said I want to optimize an extraction method and according to some published articles they start with a screening design using the Plackett Burman (it gives good results even it is studying just the mean effects) and after the screening they use a central composite design. In my field this is the most used strategy, a screening followed by a response surface design. And here are further details about what I want to do - The extraction technique is pressurized liquid extraction - I have 8 for screening and from them I am planning to choose 3 for a response surface design. - I have 2 responses to maximize - They are no restrictions on randomization, I can randomize my trial order if it is necessary thank you ... View more

Thank you for your answer. This is my first experience with DoE therefore I will need further details. As I said I want to optimize an extraction method and according to some published articles they start with a screening design using the Plackett Burman (it gives good results even it is studying just the mean effects) and after the screening they use a central composite design. In my field this is the most used strategy, a screening followed by a response surface design. And here are further details about what I want to do - The extraction technique is pressurized liquid extraction - I have 8 for screening and from them I am planning to choose 3 for a response surface design. - I have 2 responses to maximize - They are no restrictions on randomization, I can randomize my trial order if it is necessary thank you ... View more