What is the correct sequence of projects?

[James Channing]

hello, I have just bought a property that needs a) fumigation (section 1), b) landscape grading to improve drainage, c) crawspace/foundation work to repair some piers and fix sump pump, and d) minor interior remodel and retrofit window. 

Should I do a b c d in any sequence? Or it doesn’  matter?

My question is should I finish b) grading and c) crawlspace work before a) fumigating?  Or doesn’t matter?