Assessment takes place all the time in school.  We use 'Formative Assessment' everyday.  This is when our staff use the information gathered from their lessons in order to plan and teach the next steps.  We also use 'Summative Assessment'.  This is the data we record on a termly basis to ensure that children are making a good level of progress in their lessons.
After the introduction of the National Curriculum 2014, traditional levels were scrapped by the Department for Education.  Our school now assesses the children against 'A.R.E- Age Related Expectations'.  Essentially, this is were the outcomes for children are compared to the demands of the new National Curriculum for each year group.  For example, if a child achieves most of the objectives from the National Curriculum for the year group they are in, then they would be classed as being 'at the expected level'.  If a child achieves fewer of the objectives then they may be 'working below the expected level'.  A child that is achieving all of the objectives for their year group and achieving some of the objectives for the year above may be working 'above the expected level'.
Children are no longer encouraged to start the work aimed at higher year groups until they have achieved 'Mastery'.  This is when the children are using and applying their skills effectively.
The school analyses the data regularly and we use the information to plan for intervention groups to help the children progress further.