Suppose you have to install RAD or Rational packages like RPT or the Websphere Commerce Toolkit on more than one machine. Or just update more than one workstation at the last level (188.8.131.52 for example).
It can be a very big waste of time updating RAD, WAS Test Environment, Product specific fixpack or fixes using the Installation Manager automatic update.
What you need is to setup an enterprise repository.
This technote describe very well how to do it
and after you can update the enterprise repository you created
Shortly using the IBM Packaging Utility (an underestimated Rational tool), you will use the zips files downloaded from the public Rational repository (http://public.dhe.ibm.com/software/rationalsdp/)
into a server in your network and using it as internal Rational repository to install and update your workstations quickly and safely.