Shipments
One cannot obtain Artifacts and Minerals from raw production from Structures as one can with Research. Instead to obtain Artifacts and Minerals one must receive shipments of either, which are limited by available Cargo Space and the amount of production.
How Production works with Shipments
Production is gained from Structures, once gained it is held on your planets. Artifacts and Minerals (based of how powerful/valuable they are) are given ranges at which if your Artifacts or Minerals production is high enough when you receive a shipment you may receive these Artifacts or Minerals. Though a higher amount of Artifacts or Minerals production saved up will increase you chances of obtaining these Artifacts and Minerals, they do not guarantee them i.e you can still get an artifact that uses up 200 production when you had 5000 saved up.
Differences between Artifact and Mineral Shipments
Artifacts are gained one at a time, whereas Minerals are gained all at once.
When obtaining "better" Artifacts one will not receive all the Artifacts that cost less production as one would with mineral shipments (i.e. whenever you get Chrisium you will get even more Dynite, in-fact once you get past the Dynite range, Dynite will initially make up around 60% of your mineral shipments).
To put this another way, obtaining several high-AP cost artifacts will leave fewer AP for the low-AP value items, while on the other hand MP allocation is proportional and related to your rank and production capacities.