When meeting the customer and discussing the day-to-day issues I often stumble over 'desupported' software versions. Most of the time the friction starts when the customer is trying to approach support in case of a stressful event - system down - .
The real problem starts when the cause of the problems needs development attention and relates to software in 'sustaining support' the discussion usually ends quickly with 'please upgrade to a supported version' so we can proceed with our help.
I agree this is a very shortsighted answer unfortunately in many times the only right one. But.... in reality there is simply no time for an upgrade so "please upgrade" is the last thing you like to hear.
Therefore the theme Supportability gets a lot of attention in our teams. Usually the first question I ask when the 'hot-potato' surfaces is 'how did you implement the version management process in your IT department' and WHO is responsible for maintaining this ? The reaction on the faces of the IT managers often explains more then words can tell.
My 'simple' advice is to make sure you have your strategic systems on your radar. Make sure you know the product-lifecycle dates (of the compete stack so database, middleware and (third party) application.
Agree on your plans with the user community (the business). Once agreed, take the plan to action when you are planning for your maintenance-downtime.
To complex .. afraid for the impact of required upgrades ? do not postpone till the first real system crash... request for help - you are not the only one dealing with this challenge.
Next time we meet, when you have lifecycle management embedded in your standard process, I hope we can discuss topics that can really improve your ROI.
p.s. more info on the Oracle product lifecycle (we call the lifetime policy) can be found on our website