After a business has been running for a number of years the likelihood is that it will have amalgamated a number of old pieces of kit. So are these still fit for purpose?
These tend to no longer be supported by the manufacturer, lack new features that could be used to improve services, may not have not been implemented to your current standard and there may also be a raft of security issues that can be exploited putting your organisation at risk.
So where to start? Assess what equipment you have. If it is end of life look at the costs of replacing it and the additional value it will bring to the business in comparison to how much it is costing to continue supporting it and what the cost will be should it fail. This information should form the basis for your business case.