Specifications first, records second.

Requirements are read back as filters before anything is run. Suppression is applied at the start, so the approved figure is the delivered figure. The handover is the point at which the criteria are verified, not assumed.

Segment splitting

Dividing a universe into parts that can be approached differently, with counts given per part.

Handover walkthrough

Going through the file, its columns and its limits with whoever will use it.

Specification drafting

Writing down the field list, definitions and rules, so the same build can be repeated later.

If you need this verified independently, say so at the start.