Need help calculating total changeover time per supervisor

Hi v-danhe-msft,

I have slightly modified the formula to:

Valid outcome = 
SUMX (
    RegistratieMaasland;
     IF( [Omsteltijden in minuten] >=0
            && [Omsteltijden in minuten] <= 30;
            [Omsteltijden in minuten];
        BLANK()
     ))

Yet I have another request regarding the valid outcome.

I have added the "subnummer" to the dataset. The subnummer is like a different packaging used for different customers. So basically when the subnummer has changed it means a change over is valid. Sometimes only the amount of people on a line has changed (typically when a person becomes ill or for different purposes), this will be registered but does not mean a changeover has been conducted. 

I have highlighted an example for which the outcome is valid.

The change from production order 6070 to 6071 is an example of an invalid outcome, here the amount of people has changed and I don't want the outcome to be computed (the cell shall be blank).

Would you be able to modify the formula with the above-mentioned request? Thanks in advance!