p_boarder:

I generally try to leverage one of the built in process management tools, and write a reporting application as needed. However, that's not what you asked, so here's what I'd do--I'd use a state machine for each process. So once the process goes to 'running' it won't be modified until its starting timeout ends, etc. Something like:

my %Jobs = (
    Florb => { startup_time=>120, shutdown_time=>45, state=>'stopped',
+ },
    Zooki => { startup_time=>60,  shutdown_time=>10, state=>'stopped',
+ },
);

while (1) {
   my $desired_state = get_desired_state();

   for my $J (keys %Jobs) {
       my $job = $Jobs{$J};
       if ($$job{state} eq 'stopped') {
          if ($desired_state eq 'running') {
             $$job{state} = 'starting';
             $$job{time} = time;
          }
       }
       elsif ($$job{state} eq 'running') {
          if ($desired_state eq 'stopped') {
             $$job{state} = 'stopping';
             $$job{time} = time;
          }
       }
       elsif ($$job{state} eq 'starting') {
          if ($$job{time} + $$job{startup_time} < time()) {
             $$job{state} = 'running';
          }
       else {
          if ($$job{time} + $$job{shutdown_time} < time()) {
             $$job{state} = 'stopped';
          }
       }

       # doze a little
       sleep 10;
    }
}
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...roboticus

When your only tool is a hammer, all problems look like your thumb.