In the work plan, the PBO can set out his priorities, but the requirement of “shall”, as you've interpreted it, is correct. He's required to do it.
On May 29th, 2017. See this statement in context.
On May 29th, 2017. See this statement in context.
May 29th, 2017 / 7:25 p.m.
Assistant Secretary, Machinery of Government, Privy Council Office
In the work plan, the PBO can set out his priorities, but the requirement of “shall”, as you've interpreted it, is correct. He's required to do it.
See context to find out what was said next.