'Controlled Assessments' have now largely replaced the 'Coursework' component in GCSE subjects. Controlled Assessments (CAs) are considered a fairer measure of student performance, being less open to contributions from substitutes (family members, tutors, or online sources etc).
To me the CA looks like an adaptation for schools of the old 'open-book' style of exam, once restricted to some higher education courses. The paper is given out a week or so before the day when all candidates gather to sit the exam. Students therefore have an opportunity to thoroughly prepare their answers - though not to the extent of bringing finished essays into the hall and copying them out.
Going through higher education years ago, I considered myself lucky never to have this particular examination torture instrument inflicted on me - for it seemed to me then that, far from easing the nervous pressure of a conventional unseen exam, the 'open-book' formula could unite the different demands and stresses of term essay-writing and examination hall performing. Because they were such different arts - normal essay-writing being leisurely and perfectable, and exam-writing, intense and improvisatory - the probability in the open-book exam of falling between stools, neither digesting questions adequately, nor answering them spontaneously, must be high for many candidates. And to have the worry extended over several days beforehand ...
My sympathies are therefore now with Year 10 & 11 students who have been bringing in notes and draughts for CAs this week on, for instance, Romeo and Juliet and Pride and Prejudice. The essay questions and instructions they have to work to are clear - but the length and conditions of the challenge are formidable: 1200 words in 4 hours over 4 days seems typical.
If we have sufficient time at the Centre, I try to get students to break down the task ahead of them into as many parts as there are days or sessions for the CA, and then define a clear, distinct sub-theme for each day. This we can then further subdivide into a sequence of 3 or 4 paragraphs - each with its own identifiable topic of points and supporting quotations. A painstaking student can then go into the CA equipped with a detailed template for whichever stage lies ahead of him or her on the day, and be able to build up a body of argument, which doesn't repeat or lose thread, and is reasonably polished.