After modifying the High Level Scope, and finalising the resources, you can now prepare a Final Schedule. Once the resources have been assigned, ensure their workload is balanced. This will become the benchmark against which the project is managed.
It is common sense to realise that you will not know all
the work you have to undertake from day one. A consequence
of this is of course that there will be additional work to
be included in the schedule as the project progresses. Some
organisations are enlightened enough to allow for contingency
but most frown on the practice. The best way to cope is to
take the pessimistic view when estimating time. If you think
something will take somewhere between 5 and 9 days, put it
in as 9 days. Ask yourself how often you have overestimated
the effort required rather than underestimated the effort?
A key part of this activity is to ensure you have a number
of milestones to check progress. Each deliverable should have
a milestone. For example an activity in your schedule may
be "Produce risk assessment". It should be followed by a milestone
"Risk assessment complete".
Now that your scope is translated into a schedule and resources, you need to immediately implement change control. Any suggestion of a scope increase now becomes subject to the change control process you developed earlier in the phase.