@startuml
' convert it with additional command line argument -DRELATIVE_INCLUDE="./.." to use locally
!if %variable_exists("RELATIVE_INCLUDE")
  !include %get_variable_value("RELATIVE_INCLUDE")/C4_Context.puml
!else
  !include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Context.puml
!endif

'LAYOUT_TOP_DOWN()
'LAYOUT_AS_SKETCH()
LAYOUT_WITH_LEGEND()

title System Landscape diagram for Big Bank plc

Person(customer, "Personal Banking Customer", "A customer of the bank, with personal bank accounts.")

Enterprise_Boundary(c0, "Big Bank plc") {
    System(banking_system, "Internet Banking System", "Allows customers to view information about their bank accounts, and make payments.")

    System_Ext(atm, "ATM", "Allows customers to withdraw cash.")
    System_Ext(mail_system, "E-mail system", "The internal Microsoft Exchange e-mail system.")

    System_Ext(mainframe, "Mainframe Banking System", "Stores all of the core banking information about customers, accounts, transactions, etc.")

    Person_Ext(customer_service, "Customer Service Staff", "Customer service staff within the bank.")
    Person_Ext(back_office, "Back Office Staff", "Administration and support staff within the bank.")
}

Rel_Neighbor(customer, banking_system, "Uses")
Rel_R(customer, atm, "Withdraws cash using")
Rel_Back(customer, mail_system, "Sends e-mails to")

Rel_R(customer, customer_service, "Asks questions to", "Telephone")

Rel_D(banking_system, mail_system, "Sends e-mail using")
Rel_R(atm, mainframe, "Uses")
Rel_R(banking_system, mainframe, "Uses")
Rel_D(customer_service, mainframe, "Uses")
Rel_U(back_office, mainframe, "Uses")

Lay_D(atm, banking_system)

Lay_D(atm, customer)
Lay_U(mail_system, customer)
@enduml