Understanding how sequences work

A sequence is the numbering pattern for one document type. Tooling Metrics uses it to suggest the number of each new record — purchase orders, items, tools, parts, picklists, and the other types listed in Sequences. Every organization starts with one sequence per document type, so numbering works from day one.

How the next number is built

A number is the Prefix, followed by the Subsequence evaluated against today’s date (if set), followed by the Next Number zero-padded to Size digits.

Prefix	Subsequence	Size	Next Number	Generated number
PO	/%y/	4	42	PO/25/0042 (in 2025)
T	(blank)	5	1	T00001

The subsequence is a date pattern, so a sequence with /%y/ starts showing the new year automatically on January 1. The counter itself does not reset — set Next Number back by hand if you want each year to start at 1.

When the counter advances

1. When you open a new record, its number field is filled with the number the sequence would generate now.
2. When the record is saved, the sequence’s Next Number increases by its Step.
3. The counter only moves when a record is actually created, so opening and cancelling a form doesn’t use up a number.

Records created automatically — the purchase orders, transfers, and scrap lists from the Inventory Scheduler, the receipts and restocks from Automatic Purchase, and the picklists from the Setup Assistant — take their numbers from the same sequences.

Things to keep in mind

• Changes apply to new records only. Existing documents keep their numbers.
• The counter doesn’t check for duplicates. Lowering Next Number, or setting Step to 0, makes the sequence generate numbers that are already in use.
• Each prefix must be unique in the organization, so each document type’s numbers are easy to tell apart.
• A deleted sequence stops suggesting numbers. New records of that type then open with an empty number field.

To change a sequence, follow Set up document sequences. Every field and default prefix is listed in the Sequences reference.

Related articles

• How the permissions model works
• How units of measure work
• Set up your organization