Wikipedia provides Douglas Adams? explanation of how the name came about.
?Douglas Adams writes in the notes accompanying the published volume
of original radio scripts that he wanted Slartibartfast's name to
sound very rude, but still actually broadcastable. He therefore
started with the name "Phartiphukborlz", and changed bits of it until
it would be acceptable to the BBC. He came closer to achieving this
aim the following episode, with the double-act Vroomfondel and
Majikthise. He adds to this statement in "Don't Panic: The Official
Hitchhiker's Guide to the Galaxy Companion", an analysis by Neil
"...One thing I don't think I explained in the script book was
that I was also teasing the typist, Geoffrey's (Perkins) secretary,
because ... she'd be typing out this long and extraordinary name which
would be quite an effort to type and right at the beginning he says
'My name is not important, and I'm not going to tell you what it is'.
I was just being mean to Geoffrey's secretary".
Douglas Adams ?
Don't Panic: The Official Hitchhikers Guide to the Galaxy Companion (Paperback)
by Neil Gaiman
Speaking as a Brit, one view of it is that he wanted to play on the
structure of the word and for it to sound, especially if
mis-pronounced, something like ?start a blast fart?. You will notice
that his first attempt at the name started with Phart. Very much
I hope this answers your question. If it does not, or the answer is
unclear, then please ask for clarification of this research before
rating the answer. I shall respond to the clarification request as
soon as I receive it.
Slartibartfast " douglas adams"