If you find that you lose track of the frequent changes to the benefit system, NAWRA (National Association of Welfare Rights Advisers) has a very useful chart which you can download. It itemises changes since 2011 and future changes planned up to 2018. The chart includes details of each change and provides analysis and an assessment of the likely impact. It is regularly updated.
There are a lot of other resources on their website, aimed primarily at Advisers, but of interest to other professionals as well.