On demand manufacturing means buying parts from capacity rather than from stock: you upload a file, a network quotes it, and parts are made when you order them. It removes minimum order quantities and inventory, and it moves the risk of idle capacity onto somebody else. Like every convenience it has a price, and knowing where that price sits is what makes it useful.
What you are actually buying
Access to a pool of shops with a quoting layer on top, or a single supplier with enough capacity to treat your job as routine. Either way you are buying availability and speed rather than the lowest unit price. The quote is generated from geometry, so it is fast, consistent and blind to anything the model does not express.
Where it genuinely wins
Spares and service parts, where holding inventory for years is expensive and demand is unpredictable. Bridge production between a prototype and a tool. Products whose lifetime volume never justifies tooling. Seasonal or campaign driven demand. And any situation where the cost of being out of stock is much larger than the premium on the part.
Where it quietly fails
When the same part is ordered repeatedly and nobody notices it would be far cheaper tooled. When the network routes successive orders to different shops and the parts are not identical, which matters more than it sounds on fitted assemblies. And when the drawing carries requirements the automated quote never read, so the parts arrive dimensionally fine and functionally wrong.
Making it work
Send a drawing as well as a model whenever a dimension matters. Ask whether repeat orders go to the same supplier, and ask for that if consistency matters. Review the annual spend on any part you order more than a few times a year, because that is where tooling quietly becomes the cheaper answer. And keep a real supplier relationship for the parts that carry risk.
Questions people ask about low volume manufacturing
What is on demand manufacturing?
Ordering parts to be made when needed, usually from a digital quoting platform or a network of shops, rather than from stock or against a minimum order quantity.
Is it more expensive?
Per part, usually. Whether it is more expensive overall depends on what inventory, tooling and stockouts would have cost instead.
What quantity counts as low volume?
There is no threshold. Practically, it is any quantity below the point where dedicated tooling pays for itself, which varies enormously by process and part.
Will repeat orders be identical?
Not necessarily, if the network routes them to different shops. Ask for supplier consistency in writing if the part is part of a fitted assembly.