The batch log

In most categories a batch log is good practice. Here it is part of what 21 CFR 111 requires, and the rule is explicit that production and process control records must exist.

This one is a legal record

The rule expects a batch production record showing what was made, from what, by whom, against which specification, and that a quality unit reviewed and approved it.

Which means the log is not a note to yourself. It is the document that demonstrates the batch was made under control, and its absence is a finding regardless of how good the product was.

What a row contains

Date. Product and formula version. Batch code. Batch size. The lot number of every component, with the actual weighed amount beside the target. Pre-blend steps. Blender, fill level and blend time. Sampling points and results. Fill check-weights from start, middle and end. Units produced. Reserve samples taken. Who made it and who approved it.

The columns that earn their place

Component lot numbers, because they are the link from a customer's tub code to a supplier's material, and they cannot be reconstructed afterwards.

Actual weights against targets, because the difference is the only evidence available when a batch behaves unexpectedly.

Blend time, because it is the parameter most likely to drift when somebody is in a hurry, and uniformity depends on it.

Check-weights at three points, because a trend across them is the fill drifting and a spread is the powder varying.

What it lets you answer

A customer has a tub with a code and a question. What is in it, when was it made, which supplier lots, what was the blend uniformity, what did it assay at, and where is the reserve sample.

Ten minutes with a good log. Otherwise, a question you cannot answer about a product somebody is ingesting daily.

References