the difference originates in Roman law (dolus in eligendo) - "the responsible" is the guy who made the mess and "the accountable" is the guy who empowered him

dear mkavurcic,

Thanks for this answer. Let's say that my question was a bit more ProjeQtOr centric to understand how to set the accountable person (as the responsible is clearly set on tickets, actions, activities, ...

it depends on your Project Organization - i.e. responsible for ticket can be a team member who works on or coordinates tasks, and accountable can be a team leader

Hi,

Accountable is defined only for Tickets.
We had to distinguish for tickets 
 - The accountable = the one who will ensure things are done (en français : le responsable)
 - The responsible = the one who executes (en français : l'acteur)
As we already have for activities (and sure names are coherent with tickets)
 - The responsible = the one who will ensure things are done (en français : le responsable)
 - The assigned resources = the ones who execute (en français : les acteurs)

When designing ProjeQtOr, at first, we fell in the ambiguity of RACI definition from French to English
English RACI stands for : Responsible, Accountable, Controller, Informed
French RACI has several translation : Responsable, Acteur, Contrôleur, Informé : there Responsibility and Accountability are switched from A to R

At first, ProjeQtOr only had Responsible, which was in French "Responsable"
So, when we has to make difference on ticket between Actor and Accountable, we has to keep Responsible unchanged because it was used for rights management, so we introduced Accountable.

As a summary :
 On Activities : the field Responsible stands for the Accountable, Actors are Assigned resources
 On Tickets : the fields Accountable stands for the Accountable, Actor is the Responsible
 On all others : the field Responsibles stands for Accountable and Responsible (is the actor is accountable for the item)