"Rebekka-Marie" wrote:
I would like to distribute Demand randomly over 30 days.
(Possibly with a specific Demand sum overall and maybe a
stated variance in Demand changeing)
Is there a Random Generator in Excel which could help me
to do that?

Perhaps. Your description of the random distribution and stochastic process
is not clear to me. But you might take a look at the RNGs provided with the
Data Analysis tools.

Alternatively, you can craft your own RNG using RND and RANDBETWEEN
functions. Again, your RNG requirements are not clear enough for me to be
specific.

The downside is of using RND and RANDBETWEEN: they are "volatile"
functions. They change every time any cell in any worksheet in the workbook
is modified directly (edited). There are methods to avoid that or at least
mitigate the impact.