By mandating, as part of the minimum standards criteria (discussed in parts 5 and 6) that schools participate in a quality assured improvement programs.
You'd neeed someone exceptionally bright (highly experienced in education with at least an MEd and a recent MBA as well) organising the regulation of the frameworks for such programs at the inspectorate.
They'd need a small team of people who worked to quality assure improvement programs (individual schools might be quality assured or bodies which groups of schools worked with may be).
The at last schools would have the freedom to select who they worked with to mentor them on quality improvement. Wouldn't it be wonderful if we could have PRUs being mentored by bodies with specialist expertise in running PRUs for example?