assuming this runs as 1 program, and does not fork: maybe something like this will work:
a=`ps aux|grep program | grep -v "grep program"| wc -l`
this is really primitive, but it may give you an idea. this will give you a number of things running as "program". then you can do an if then statement: if greater than/equal 1 (ie. program running) return w/o error, but if not greater than/equal 1 (ie. program not running) then start program and log error.
hope this gives you an idea. This could easily be done in bash with the above code and an if/statement. Again, this is fairly primitive but may get the job done: you would just put the script in crontab to run every 15 minutes or something.