The carriers want to find your parcel.  

In order to do this the carriers conduct an audit of the parcels journey.  Traces can take extra time because the courier will conduct a search throughout their network to locate a parcel.  They will require a detailed description of your outer packaging and the contents to identify your shipment if found.  

Traces can take up to 30 days and if the shipment is not found the carrier will convert the trace into a missing claim. 

Keep a positive outlook, parcels are sometimes recovered during the trace process!