Lot tracking for small factories: a practical guide

If a client calls and asks "how much of my order is ready?", can you answer without walking the floor? For many small factories the honest answer is no. Pieces from different orders mix in the same trays, and nobody knows exactly which batch is where.

Lot tracking solves this. It sounds like something only big plants do, but it is simple, and it is the foundation for every other kind of production tracking. This guide covers what a lot is, how to number it, and how to follow it through your stages.

What is a lot?

A lot (or batch) is a group of identical pieces that move through production together. Same product, same size, started at the same time. For example: 800 six-inch pipe handles for one client's order.

Every lot has:

• a lot number, like L-14,
• a product and size,
• a planned quantity,
• optionally, the order it belongs to.

Why bother with lots?

Without lots, you only know totals: "we made 2,000 handles this week". With lots, you know:

• Which order each piece belongs to, so you can tell a client exactly how much of their order is done.
• Where each batch is, stage by stage.
• What went wrong with a batch, if rejections spike, you know exactly which lot and which stage.
• When a batch is finished, because every piece is accounted for: finished, rejected, or still waiting somewhere.

How to number lots

Keep it boring:

• Use a simple running number: L-1, L-2, L-3. Don't put dates or product codes in it; that information belongs alongside the lot, not inside the number.
• Write the lot number on the tray, bin or tag that travels with the pieces.
• Never reuse a number.

Splitting an order into lots

Big orders are often too large to run as one batch. Split them into lots that fit how you actually work, for example one lot per day or per raw-material batch. An order of 2,000 pieces might become lots of 800, 600 and 600.

Keep track of how much of the order is planned into lots so far. When planned equals the order quantity, every piece of the order has a lot.

Following a lot through your stages

For each lot, at each stage, record:

• Good pieces that passed,
• Rejected pieces,
• and therefore pieces still waiting at that stage.

Good pieces from one stage become the pieces received at the next stage. When everything is either finished at the last stage or rejected along the way, the lot is closed.

Corrections without losing history

People make mistakes when entering counts. Don't erase them. Instead, record a correction that reverses the wrong entry, and enter the right one. This keeps an honest history of who entered what and when, which matters the moment someone asks why the numbers changed.

How LineSight does it

In LineSight, you create an order for a client, product and size, then plan it into lots. Lot numbers are given automatically. Operators enter good and rejected pieces per lot at each stage from their phones. Each lot page shows every stage with received, good, rejected and waiting pieces, plus the full entry history. Wrong entries are undone with a reversal, not deleted. A lot closes by itself when all its pieces are accounted for, and the order shows how much is planned, finished and still remaining.

The takeaway

Lots turn "we're working on it" into "lot L-14 is at drilling, 310 done, 442 waiting". Start with simple running numbers, a tag on every tray, and good and rejected counts per stage. Everything else, from on-time delivery to cutting rejections, gets easier once you can see each batch.