To be able to know if Essential Flow is working the people responsible for each work stream must report the four dates of Essential Flow: the start date, the date the work enters the Constraint, the date the work leaves the Constraint, and the date the work stream is finished.
Workstreams that start too soon (or too late) need to be looked at. Workstreams that enter the Constraint too late(or too early) need to be checked.
The responsibility for monitoring workstreams need to be assigned to someone who has the resources (or is given the resources) to make sure the data is up to date and the authority to go talk with the people responsible for the work stream if it gives distress signals.
Questions
Who has the responsibility for managing your company’s portfolio of work-streams?
What tools do they use to help them monitor what is going on?
What steps do they take when they notice that some work streams have problems?