The Portfolio is a file of evidence of the ISA activities undertaken by the school. It needs to capture not only whether the school has actually implemented the action plan but also the impact the activity had on the students.
A well put together portfolio reflects the work don and allows the assessors an insight into the school and its values, ethos and approach to teaching and learning. Remember no matter how well you have executed the Action Plan, the ISA Assessment panel will have no way of knowing this except through the Portfolio. So the success or failure of the school will depend upon the way in which you put together the Portfolio.