SAAS is also the easiest to maintain, because at any one time there's (usually) only one version of the software running on one OS & hardware version. And the

SAAS is also the easiest to maintain, because at any one time there's (usually) only one version of the software running on one OS & hardware version. And the vendor is running it, so access to logs and core dumps is effortless. It's a big problem getting logs, etc. from customers running on-prem software.