Voluntary redundancy is either a boon or a curse dependent on management.
It is a form of encouraging natural wastage.
However, without controls, it can be a very damaging way for a company to reduce manpower levels.
What can happen is that the most useful people to the company are also often the most marketable, these are the people who could go at any time just for a better job elsewhere; by allowing them access to redundancy money just sweetens the pot for them.
The ones that usually do not want to volunteer are usually the ones who would have trouble getting any new job and holding it through the first few trial months.
Generally management should have a list of people who will not be allowed voluntary redundancy.
This list should include core personnel they identify as being essential to the long term company health (the ones that could up sticks at any time anyway) and real dead beats they want to see go without taking any extra money with them.
Anyone opting for voluntary redundancy and being refused should know they are in a strong bargaining position and might leverage some extra dosh at review time without all this "lucky to still have a job" "Times are hard" b*****it they usually hand out when not handing out decent rises.
On the other hand, "Voluntary Separation", as described by Plasgears sounds like bad management at work who want to chase people out and then claim they left of their own free will and hence are not entitled to redundancy.
In the UK many of managements little tricks are countered in the legislation. For example, any significant change in working conditions or job description ( a very valuable "must have") is considered a "constructive dismissal" i.e. they must pay redundancy.
Basically, if they tell you to go or ask for volunteers to go, they have to pay the redundancy.
JMW