Affordable Housing, OAN and Viability - Public forum - Planning Advisory Service (PAS)

Is anyone aware of any examples where an authority has been required to increase their OAN in order to meet affordable housing needs, as viability of development has meant that a lower afforable houisng policy requirements has had to be set?

Or on the contrary where a Plan has been found sound (post NPPF) without meeting the full afforable housing needs?

Many thanks