Reliability. Can you take the risk that your phone systems fails and your customers can't contact you? They may go somewhere else! Don't let your phone system become the most neglected link between your people and their clients.
Expense. It can be very costly to maintain an old phone system because parts are expensive and specialists are required for servicing and programming. Maintenance costs on an old system can be higher than the repayments on a new system..
Functionality. Older systems may not provide basic functions such as voicemail and auto attendant. Many companies and their employees has to work within the limitations of the phone system, rather than having the ability to set the system up to work for them and manage the calls in an effective and productive manner.
Ease of use. This follows on from the above, with many companies directing their calls through a manned switchboard. By the use of technology and not a dedicated receptionist, incoming callers can be directed to the correct person, rather than going round the houses. Response times are shortened and calls are handled in an overall more professional manner.
Home Workers. Many systems now have the ability to connect seamlessly via the internet to home workers based anywhere in the world. Each of your home workers has an extension on your phone systems and you needn't incur call costs.
Carbon Footprint and the Environment. A phone system can reduce your carbon footprint by eliminating unnecessary travel. This could be home workers not having to drive to the office, or video links to overseas offices reducing the amount of flying required.