Many people seem to confuse with IVRS and Auto-attendant and Answering Machine!
Though Auto attendant and Answering Machine may be compared, but comparing IVRS with either of them is comparing armored vehicle with F-117! ( Hope I have given the right analogy.:) ), they have similarities but they have major difference in usage, scale and features.
1. Auto Attendant attends a call, and can transfer a call to extension as per caller dialing. IVRS can do all these too. But IVRS can retrieve data and playback information which Auto Attendant can not do! Answering Machine normally has one prompt which gets played after certain number of rings if the calls go unattended, and record a message from the caller. Also it plays back the recorded messages. These are the functons of Answering Machine.
2. IVRS is very smart and intelligent system while, Auto Attendant and Answering Machines can not be said to have any intelligence! They do few things as per pre-programmed! IVRS has vast applications! It has not applications in almost every industrial sectors including pharmaceutical research activities too.
3. IVRS can work like an answering machine or auto attendant, but they can not work like an IVRS apart from the above tasks!
4. IVRS can work like a voice portal while no one can even imagine auto attendant or answering machine to work like voice portal.
5. Auto Attendant and answering machine are low cost equipment, normally built in phone instrument or EPABX. While IVRS requires Server Class PCs to run, costly CTI cards and costly software engineers. Also IVRS can have few dedicated IVRS blogs, while I doubt if auto attendant or answering machine will have more than 2/3 pages in some websites. 🙂
6. Auto Attendant and Answering Machine has limited configurations and limited recording options, IVRS has almost unlimited applications and configurations!
I hope these six reasons should be enough to convince anyone the difference between IVRS, Auto Attendant and Answering Machine! There is a Voice mail System too which is a CTI application again, but a single function of storing recorded message! So, one can think of Voice Mail System (VMS) as a one kind of IVR Application .