I was looking at one article that described Swinging as a conservative venture while Open Relationships was more of a liberal one.
when looking at it I could see the difference. Open relationships can be more about being free and unrestricted but still attached.
Swinging can be more about having a fun dinner with the neighbors like any other dinner party only it ends in fucking each other.
If these were the definitions I would presume that polyamory would be defined as an arrangement based on love and relationships as opposed to fucking and could apply to any kind of configuration.