iThree dates that get confused
A brownfield line has at least three dates: the planned handover in the project tracker, the mechanical completion when construction finished, and the date operations accepted it into service after a successful test. Only the last one lets a well flow. Forecast workbooks, management slides and often the project tracker itself use the first as if it were the third.
iiWhat a commissioned line looks like
A commissioned line has a signed service test, a line status in the operating system, a valve line-up that has been walked, and an operations approval. A plan that says "available from October" has none of these. When we write a commissioning sequence we build it around hold points. Each needs evidence from the field before the next step: valve positions confirmed by a walk-down, an open path proved, communications and monitoring in place, differential pressure checked, stable receipt at the destination.
iiiHow the error spreads
A forecast that enables a transfer line from its planned date shows oil arriving at the receiving facility from that month. The deferral register then records the wells behind that line as recoverable with a near-term target. The management brief adds the barrels. When the line is three months late, every one of those documents is wrong in the same direction, and the error is found by the person asking why actual production is below plan.
ivThe discipline
Carry the planned date as a planned date in every document. Label it. Switch to an actual date only when the evidence exists. In a data system this is a field-level rule: planned and actual are separate fields, and the actual is filled from the acceptance record, not from the plan.
A planned date is a planned date. A commissioned line has a log.