A little while ago, work upgraded our voicemail system. This new system is a nightmare to use.
When you are designing a system you need to give a priority level to all the tasks that are available and create a heirarchy. Not all tasks are equal. For a voicemail system the key task that is being carried out 99% of the time is checking a message that has been received. Other tasks like creating a message (although initially is important, is hardly ever used again) do not have a priority level the same as other interactions.
Have a listen to what is required to receive a message (MP3 file).
It takes nearly 50 seconds before I can receive a message and it buries that option way down in the menu structure. It is also set up that I have to use a different key combination to get to the menu choice I want (for instance, I can’t keep pressing 1 to get to the key function).
Give key tasks higher priority in the navigational layout and make them simple to get to.