Generally speaking, companies must weigh the pros and cons of upgrading or updating any system. It is accepted that physical assets such as machinery or equipment must be maintained at specific intervals.
Furthermore, the projected end of life date is typically established at the time of purchase. Equipment kept in use past its projected EOL requires additional maintenance and upkeep and often hampers productivity or increases risk and most companies would not dispute this fact.
Software systems are no less critical. Software applications and operating systems also have a projected EOL, but often the temptation to extend the service life of these assets is greater than for a piece of equipment that you can touch and feel.