Valid or effective?

[Mark_000]

Hi,
Assuming that I have a design intention for a mobile phone and I would like to confirm whether it works well as i expect. Is it appropriate to use "valid" or "effective" in this situation?
eg: The design improving is not valid since it has been proved ineffective in our test.

Also, if I want to tweak my sentence as below which words with the underline are correct or more natural
eg: The design improving is not valid since it has been proved ineffective for using?/applying? in the effective?/actual? life.

Thanks for giving me your kindly explaination



BR
Mark

[5jj]

You seem to be saying the same thing two or three times.

How about, "The design alteration proved ineffective in our test"?

You can't really call it an improvement if it didn't work.

[Mark_000]

Thanks for your explanation whereby I get a progress.
In the second sentence I wondered which words with the underlines(using or applying, effective or actual) are natural in that sentence. Now I think that sentence should go with "using" and "actual".

[5jj]

The design adaptation proved ineffective in practice/when tested/when tried (out).

There may be better ways of saying this, but additions are unnecessary; I suppose you could add in real-life situations.