When you live in the country and have hoses that are kept outside, they will occasionally get chewed on. I fix them when that happens, with a hose repair kit:
If you haven't used one of these, you basically cut the hose on either side of the hole, losing a few inches, then put the metal couplings in each new end, use the hose clamps to hold the hose onto the couplings and then screw the couplings together. There are several styles with varying amounts of metal and plastic but they all work essentially the same way. They cost $5-$10 and are often sold packed in bubble packs.
If you imagine a formerly 50-foot hose that has been patched like this say 50 times, with 6 inches or so between patches, it would be ridiculous as a hose and also the money, energy and packaging that has gone into making hose patches would exceed those of a new hose. So clearly there is some number of patches that is the limit, and on reaching that I should buy a new hose, and then remove the patch kits from the old hose and save them to use for patching the new one when it is inevitably chewed, (Note: inevitably means once or twice a year across all the hoses I use - three or four are typically out at a time. Putting the hose away after each use is impractical and besides, my shed gets more critters than my lawn does.)
How can I calculate (other than the ease of coiling, uncoiling and using the hose) the number of patches at which I should just switch to a new hose? Keep in mind I will reuse the patches from hose to hose.