A "lot" of parts represents batch of parts, obtained from a single source, identical in every respect. Without lot control, all stock of a given part is assumed to be identical, so when using parts for building, it isn't clear where the parts came from, or how much they cost. In case of a problem, it is also not possible to determine where problematic parts were used. In other words, without lot control you can think of your stock as a fluid: you can add to it and remove from it, but it is impossible to tell what you are removing, only the quantity is known.
With lot control, every time you add stock, lot information gets stored along with it. When you build projects, you have to select which lot you will use for a specific build. You are removing stock from a specific lot of parts and it is possible to tell where they came from and what the cost was. This gives you full traceability: from orders to manufactured devices, as well as improved costing.
Thanks to lot control, tracking is possible in two directions:
Thanks to lot control you gain full visibility into your production. If you put an ID Anything™ label representing a build onto manufactured devices, scanning that label will produce full build information, with link to specific lots of parts used in that build, showing where and when the parts were purchased.
Lot control also helps with managing physical inventory: if you print a label containing the ID Anything™ barcode and attach it to the part packaging, you will always be able to immediately identify the lot, where it came from, and where it was used.
PartsBox implements lot control so as to cause minimal friction. When adding stock, all lot information is optional. You can, but do not have to, enter additional information, use your own lot names and add comments. Even if you don't enter any lot information, you will still get the full benefits, as a unique lot ID will be automatically assigned and a short 8-character ID will be shown everywhere.
In PartsBox, lot control can be either strict or relaxed. When strict lot control is enabled, parts that do not have a lot assigned will not be available for building. This means that if you have existing stock that was not added using lot control, it will have to be removed and added again. With relaxed lot control, any stock can be used for building, but tracking information will be limited.
Additionally, PartsBox can handle lot expiration dates. Many components have to be used before a certain date. Expiry information can be added, and when strict lot expiration is enabled, PartsBox will not allow using parts from lots that have already expired.