Collecting
How to track missing LEGO pieces for each set you own
Two copies of the same set do not always have the same missing pieces. Give each physical copy its own record, then note its location, condition, and missing parts.
01 · name the thing you own
Separate the set number from the physical copy.
A set number identifies a catalog expectation: the parts and variants associated with that model. A physical copy is the box, built model, or loose collection on your shelf. Give the copy its own location, condition, and completion notes instead of treating the catalog entry as proof of what is present.
A catalog can help you define what to check. It cannot tell you that either physical copy is complete, owned, or in a particular condition.
02 · check the pieces
Keep expected, checked, found, and missing quantities distinct.
For each physical copy, record what you expect to check, what you have actually checked, what you found, and what remains missing. Variants deserve their own note when color, print, or condition changes the identification question.
| Copy | Expected | Checked | Found | Missing | Variant note |
|---|---|---|---|---|---|
| A · boxed | 120 | 120 | 118 | 2 | Check red printed tile |
| B · built | 120 | 120 | 119 | 1 | White hinge variant to verify |
The arithmetic in this synthetic example is per copy: 120 expected minus 118 found leaves 2 missing for Copy A; 120 minus 119 leaves 1 for Copy B. It is not evidence about any real set.
03 · preserve provenance
Keep identical sets separate.
Copy A and Copy B can have different gaps even when their set numbers match. Store the location and status with the copy so a found piece can return to the right record.
Do not combine the three missing pieces into one anonymous note. The total may be useful for planning, but provenance tells you which copy changes when a piece turns up.
04 · change one fact at a time
Finding a piece is different from correcting a quantity.
When you find a missing piece, update the missing note for the physical copy you checked. If the recorded quantity was wrong, make a quantity correction that says what number was replaced. If the piece moves between locations or copies, record a physical transfer rather than silently increasing both records.
This example changes one physical piece once. It does not create a second copy of the part, and it does not prove that the set is complete.
05 · plan without losing context
Use a consolidated need list, but keep the copy behind it.
A consolidated list can say “three pieces needed” for planning or sourcing. Keep the per-copy records behind that total: two may belong to Copy A and one to Copy B, with different variants or urgency. A wanted list expresses what you are looking for; it is not proof that you own the part or that a seller has sourced it for you.
- Consolidated need: three pieces across two physical copies.
- Per-copy provenance: two missing from Copy A, one from Copy B.
- Sourcing note: a search or purchase remains a separate decision and does not update a copy until the physical piece is checked.
06 · common mistakes
Do not mark a catalog expectation as a shelf fact.
- Mixing two copies because their set numbers match.
- Calling a copy complete because a catalog says what it should contain.
- Counting a found piece in both its old and new location.
- Using a wanted list as if it were owned inventory.
- Recording a quantity correction without keeping the number it replaced.
07 · common questions
Keep the copy and the need connected.
- Can a part belong to two builds?
- One physical piece can only be in one place at a time. If it moves, record the transfer and update the copy that gave it up.
- Does adding a set prove it is complete?
- No. A set number describes an expectation; completion needs a check of the physical copy.
- Can a scan or wanted list prove I own the piece?
- No. Identification and sourcing notes do not replace a checked physical record.
08 · next step
Keep each copy in its own collection record.
Brick Pulse's collector records are the natural place to keep set copies, locations, and missing-piece context together. This private preview does not promise automatic catalog completeness or replacement sourcing.