Dunning Plans

 I am new to Advanced Collections. This is already implemented here using one Dunning Plan, on 11.5.10. Users now want to add a second Dunning Plan to meet requirements for a different part of the business.  I am getting conflicting advice, one advice is that there can only be one Dunning Plan at a time in existence, which I find hard to believe, the second advice is that we should be using Collection Strategies instead of Dunning Plan if we want to do Dunning differently in separate parts of the business.

Can anyone advise please