Hiro,

Probably the MOST IMPORTANT FACTOR in your museum business plan
is NOT TO COUNT ON ADMISSIONS EVER FOR 100% OF YOUR INCOME.  Lots
of people make lots of plans showing how they will be able to meet
all their expenses from admissions and museum-store sales, and few
if any do it.

You will hear lots of consultants tell you how easily [relatively]
it will be to meet all your expenses with fees.  DON'T BELIEVE ANY
OF THEM.  You must plan from the beginning for some subsidized
support - an endowment, trust fund, etc. - to make up the
difference.  Do not expect to make more than 60% of operating revenue
from fees.

Maybe some other folks on the list have success stories of
continuing support from just admisssions and fees, but I haven't
seen them in my albeit limited experience.

--
Fred R. Reenstjerna, Research Librarian - Douglas County Museum
Roseburg, Oregon  USA - [opinions expressed are my own, and I
stand behind every one of them]