R
Hi guys,
I am currently developing a process improvement with regard to tooling on an injection molding machine.
I am proposing to run a set sample size before and after the change and compare the two results for defects on the molded part. However the defect rates could be 1.5% before and 1% after. I am trying to identify a robust enough test for significant difference.
The data is also attribute data and is not normally distributed. Is the Mann Whitley Test sufficient or do I need to be comparing proportions? If I do this will drive my sample size to an unworkable level.
Any help would be greatly appreciated.
Regards,
R.
I am currently developing a process improvement with regard to tooling on an injection molding machine.
I am proposing to run a set sample size before and after the change and compare the two results for defects on the molded part. However the defect rates could be 1.5% before and 1% after. I am trying to identify a robust enough test for significant difference.
The data is also attribute data and is not normally distributed. Is the Mann Whitley Test sufficient or do I need to be comparing proportions? If I do this will drive my sample size to an unworkable level.
Any help would be greatly appreciated.
Regards,
R.