Urban Logistics Services Supply Chain Process Modelling Based on the Underground Logistics System via the Hierarchical Colored Petri Net

Table 1

ULS-SSC top layer places and transitions description.

Place	Description	Transition	Description
Customer demand	Customer freight demand	Order processing	Demand management
Order 1,2	Order type	Calculate	Information management
Made 1,2,3,4,5	Information output	Pickup	The process of picking up goods
Instruction 1,2	Instruction issued by the control center	Warehousing	Process of warehousing
Information base 1,2,3	Information collector	Circulation processing	Circulation processing
ULS node	Station of ULS where can operate functional process	Transportation	Process of ULS transportation
Received	Consignee completes the goods receipt	Terminal distribution	Terminal distribution
End	The order finished	Accounting	Finance management
Resource 1,2	System repository
Resource condition	Resource utilization of subsystem
Equipment condition	System equipment status