General install over all unix platforms

Hello Ladies and Gentlemen, I know, this is an INFORMIX Newsgroup but this is also a place where specialists from all UNIX platforms meet. And that is, what I need. My Problem is as follows: We have to install our application on different UNIX platforms (e. g. AIX, SINIX, HP). But we have to write several install programs for that. Under 5.4 platforms, we have to write a "pkgadd", under HP we have to write ...., under AIX we have to write ... That's to much trouble. Knows anybody a installing procedure (maybe such one as pkgadd), which is available over all UNIX platforms? I hope, anybody can help us. Thank your, Volker