When a manufacturing order is produced, the components used must be recorded as consumed. The choice is between recording that manually and having it recorded automatically. This piece compares the two and how to choose in Odoo.
The two approaches
Manual component consumption means the consumption of components is recorded explicitly: as components are used in production, that use is actively recorded, so the recorded consumption reflects what was genuinely used.
Automatic component consumption, which is backflushing, means the consumption is recorded automatically, derived from the bill of materials and the quantity produced: the system works out, from the BOM, what components a produced quantity would have used, and records that.
Both result in the component stock being reduced; the difference is whether the consumption recorded is what was explicitly observed, or what the BOM implies.
The trade-off
The choice between them is a trade-off between effort and accuracy of the record.
Automatic consumption is less effort. The floor does not have to record each component's use; it is derived. For production with many components or a plant with many orders, that saving is significant. But automatic consumption is only as accurate as the BOM: it records what the BOM says was used, not what was genuinely used, so if actual consumption differs from the BOM, the record is wrong.
Manual consumption is more effort: the consumption has to be actively recorded. But it can be more accurate to reality, because it records what was genuinely used, including any variation from the BOM, and it can capture detail, such as exactly which lots were consumed, that derivation from the BOM does not.
So the trade-off is: automatic is efficient but trusts the BOM; manual is more work but captures reality.
When automatic suits
Automatic component consumption suits production where the BOM genuinely and reliably reflects what is consumed: consistent production, accurate BOMs, little real variation between what the BOM says and what is used. For such production, deriving consumption from the BOM gives the right answer, and the effort saved is a genuine benefit with no real cost to accuracy. Much steady, repetitive production fits this.
When manual suits
Manual component consumption suits production where the BOM cannot be fully trusted to reflect actual consumption, or where the manufacturer needs to capture detail. If actual consumption genuinely varies, more or less of components used than the BOM says, in ways that matter, manual recording captures the reality that derivation would miss. If the manufacturer needs precise traceability, knowing exactly which component lots went into which production, manual recording is how that specific detail is captured. Production that is variable, or that demands precise lot-level traceability, leans toward manual consumption.
It can be a per-product choice
A manufacturer does not have to choose one approach for everything. Different products and different kinds of production can be handled differently: automatic consumption for the steady, BOM-reliable production where it is efficient and accurate enough, manual consumption for the variable production or the production needing precise traceability. Choosing per product or per kind of production, rather than applying one blanket approach, lets a manufacturer get the efficiency of automatic where it is safe and the accuracy of manual where it is needed.
The honest underlying point
One honest underlying point ties this together. Whichever approach is used, the goal is component stock records that match reality. Automatic consumption achieves that when BOMs are accurate; if a manufacturer's BOMs are not accurate, automatic consumption will produce wrong stock records, and the real fix is to make the BOMs accurate, not just to switch to manual recording. Manual recording can compensate for unreliable BOMs, but a manufacturer should also be fixing the BOMs. Accurate BOMs make automatic consumption safe and make manual consumption a check rather than a correction.
The takeaway
Manual component consumption records what was genuinely used, with more effort but more accuracy to reality; automatic consumption, backflushing, derives consumption from the BOM, with less effort but only as accurate as the BOM. Automatic suits steady, BOM-reliable production; manual suits variable production or production needing precise lot-level traceability. The choice can be made per product. Whichever is used, the goal is stock records matching reality, which underscores that accurate BOMs matter regardless. For how we approach Odoo for manufacturers, see our manufacturing work.