As described earlier, the main objectives in implementing a Go-Co model are to enforce appropriate "hard charging" boundaries and inject high quality skills and processes, not to reduce DE&S costs per se. It is assumed that, over time, economies will come as ways-of-working are enhanced, but it is possible that savings will be offset to some extent by the requirement to re-skill at higher rates of pay.
At a high level, the commercial model proposed would provide fees for services, plus incentives, and would not be expected to be structured as markups or similar arrangements on contract values handled (i.e., the c.£12bn of contractor payments).
From the perspective of industry, the Go-Co transition is not designed to "tighten screws" on suppliers, but to provide a more consistent, professional and transparent contracting interface with the Customer.