Define start and finish
Choose one flow, such as enquiry to proposal or order to delivery. Define the trigger, outcome and customer. Looking inside departments alone can hide total waiting time.
Observe the handover
Record who passes work to whom, with which document and status. Count returned items, missing information and duplicate entry. Observe sample cases rather than relying only on procedure documents.
Ownership and acceptance
Agree stage owners, acceptance conditions and escalation. One process owner should monitor the end-to-end result even across departments. Pilot the change and compare cycle time with a relevant baseline.