s-b,
In my opinion, unnecessary. Know your system operating pressure and flow rate is all. Nothing like the real thing. Do your own cup water audit and adjust the heads appropriately for an actual real-time correction. Importantly, give your design parameters room for adjustments and later growth. JMHO Aloha

I would rather spend a couple months growing trees, rather than moving and measuring catch cans, then spending days entering figures into spread sheets, to try to figure out if there is a reasonable solution for that sprinkler.

Using Senniger's software I could test with a bunch of different sprinklers, with a dozen spacing variations. The best solution was an inverted micro sprinkler with a #3 nozzle running at 25 psi, spaced at 20 foot rectangular grid. That achieved (in the simulation) a DU of 90, a CU of 80 and SC of 1.5 Any spacing more than 2 feet under that, down to 10 foot spacing (using 4 times as many sprinklers) resulted in poorer uniformity.

It's not obvious given the distribution of one sprinkler how to arrange them.

s-b,

I disagree, but what is the point. There would be many best solutions unless the software is skewed to prefer a certain product programed into the solution. There are way too many variables to be weighed in the answer to come out with such a definite specific solution. It is a mere marketing tool disguised as a scientific based solution machine. How much does this software program cost? Knowing the pressure and flow rate of the source and the specification of what head you want for that pressure, you do not need a special program to do the design. Anyone else out there have an opinion or has used this tool to aid them in designing an irrigation system. Aloha