5.10 No matter how good departments' governance arrangements are, there is a strong case for external scrutiny from the centre for the largest and most complex projects because:
• the centre of government can generally draw on people with a wider range of experience and expertise than an individual department;
• in a world where departments may be adopting the more novel commercial approaches to procurement including, but not restricted, to those set out in Chapter 2, early exposure to them will help the centre to keep pace with market developments. This will enable lessons from these projects to be disseminated to a wider audience where appropriate;
• external scrutiny can be more objective about a project's prospects, and be less constrained about making appropriate criticisms; and
• there is a greater risk that a department might not be able to absorb significant cost overruns on its largest projects within its own budget, so a proportion of this risk might fall on the Exchequer with, ultimately, implications for the resources of other departments.