i need to change OS level parameter like number of user
how to change system environment variable ???
equivalent to smitty in IBM
under HPUX there is no equivalent as OSLevel the closest would be the number after the dot e.g. 11.11 11.23 etc, you would have to look at installed patches to know more...
The users under AIX is a system parameter in relation with "licenced users", under HP its a long time since I have seen something different to "unlimited user"...
Now if you are talking of the values you see when typing e.g. sysdef, then those values are kernel parameters, you would have to be root, and you even might have to recompile a kernel, people like me would do this command line, but it is not advisable for newbies so as you were talking of smitty, under HPUX you would use sam (ascii or X)
look for kernel parameters
All the best
addendum:
the params you may be looking for are nfile, maxproc, nprod, maxusers etc.. but the best for you is to read a little documentation on the subject andlike that you know what you are doing...
http://docs.hp.com/en/1219/tuningwp.html