The best solution for "How do we prevent people from using expired inventory when they should not?" is to train Users on the proactive and reactive processes we already support.

The design we settled on was not to block Users but allow them to make decisions that allow them to support a multitude of scenarios where blocking would be unwanted:

• "research and development" manufacturing
• donated
• returned to a Vendor
• used internally
• recycled
• frozen (with a label) and still used/sold
• disassembled and still usable components returned to inventory
• sold for scrap / to waste stream resellers / to circular material traders
• used for display purposes

Each of these would require that Users still be able to add them to Transfers.  

Also remember that "expiry" can also mean "best before", "use by" or "sell by" which have different meanings as it relates to product quality. In many countries these dates are mandatory, even when the underlying product will not be affected. Water never expires, but even when bottled in glass must have an expiry date, even though there is no loss of quality. 

The Alert Date (if set on the Serial) or Alert Days (if configured on the product, which will then be automatically calculated on each Serial at the time it is received) is how Uses manage being notified in plenty of time to manage expiration. Choose an alert day interval (or set alert dates) that give users plenty of time to prepare for and manage product expiration.

"REACTIVE PROCESS"

Based on the User responsible for Logistics of the Product...

..an Activity is created when the Alert Date is reached...

...which directs them to the Lot / Serial in question, where they can see the remaining Quantity (alerts are not created if there is no remaining quantity) and also see the locations where the quantity is currently stored...

"PROACTIVE PROCESS"

Any User can at any time, visit the Lot/Serial Numbers Menu and check for any Lot/Serial numbers whose Alert Date has passed (even if the Activity is marked as completed)...

#keepitsimple