One of the simplest ways to prevent unplanned outages is to ensure that you are doing everything you can to keep your system running smoothly. This includes performing basic preventive maintenance and systems management tasks that help your system perform at its peak.
Many of these systems management tasks can be automated, which helps you prevent failures that may occur because of human error or an oversight.
One way you can help ensure the availability of your system is to monitor its performance and react promptly to any problems that you encounter. You can use the Collection Services and monitors functions in Management Central to actively monitor and track the performance of your server. You can be notified of any problems that jeopardize the availability of your system in time to react and prevent an unplanned outage. For more information on how to plan for and manage the performance of your server, see Performance.
Fixes are also an important systems management component that can help
you keep your system available. When problems are discovered in iSeries™ programs, IBM® issues
a fix (also known as a PTF, or program temporary fix)
to correct the problem. You need to be aware of fixes and install them on
your system to ensure that your system is operating at its optimal level.
You should create a fix management strategy and make checking for and applying
fixes part of the routine maintenance for your server. For more information
on how to obtain and apply fixes, refer to Use
software fixes. For help in determining a strategy for preventive maintenance
based on your iSeries environment and applications, try the Fix
Maintenance Advisor 
.
In addition, you should also develop a strategy of when and
how new applications will be added to your systems. Before adding a new application
or updating an existing application, ensure that any software, hardware, or
other dependencies are understood and in place. It is also important to plan
and test these new or changed applications before introducing them into a
production environment to help avoid potential outages or other unexpected
impacts.