Van won't start

Please help!!  I have a 2011 Town and Country
minivan. This past fall we had issues with what we
thought was the battery so we replaced it.
Realizing quickly that it was the alternator that
needed to be replaced so we did that. Then every
30 or so times I would start it it would not start at
all. It would be very random every two weeks or so
it just would not start. Sometimes it would start
after the third try sometimes it would take a half
hour but eventually would start again. No problems
whatsoever all winter long living in mid Michigan
with lots of snow and ice. Now that we are thawed
out and having nice weather again my van is acting
up a lot more often. Sometimes it will take a jump
and other times it just will not start at all. It acts
like it wants to but never turns over.  I have two
kids and run my own business and cannot have an
unreliable vehicle. It will not start at all at the
moment. Help!