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Migration L1 Context Diagram Example

This context diagram highlights the key migration principle: the major change is in the integration layer, not in core business systems such as Portal, ERP, ERP-Finance, and Warehouse Management System.

It visualizes current state and future state side by side.

Example Diagram

Preview Mermaid Code
C4Context title Migration Context - BizTalk to Azure Integration Services Person_Ext(customer_user, "Customer", "Order submit and status checks") Person_Ext(supplier_user, "Supplier", "Invoice and product updates") Person_Ext(logistics_user, "Logistics Partner", "Shipment and delivery milestones") System(portal, "Portal", "Unchanged customer-facing system") System(erp, "ERP", "Unchanged core business system") System(erp_finance, "ERP-Finance", "Unchanged core business system") System(wms, "Warehouse Management System", "Unchanged core business system") System_Ext(payment_gateway, "Payment Gateway", "External payment processor") SystemDb_Ext(carrier_tracking, "Carrier Tracking DB", "External delivery confirmation store") SystemQueue_Ext(edi_gateway, "EDI Gateway", "External B2B queue") System(biztalk_current, "BizTalk Server", "Handles legacy integration workloads") System(azure_target, "Azure Integration Services", "Handles migrated and new workloads") Rel(customer_user, portal, "Submit order and query status", "HTTPS / JSON") Rel(portal, biztalk_current, "Current order API", "REST / SOAP") Rel(portal, azure_target, "Migrated order API", "HTTPS / REST") Rel(supplier_user, biztalk_current, "Current invoice and file exchange", "SFTP / FILE") Rel(supplier_user, azure_target, "Migrated invoice integration", "SFTP / Event") Rel(logistics_user, biztalk_current, "Current shipment status", "FILE / REST") Rel(logistics_user, azure_target, "Migrated shipment status", "REST / Event") Rel(biztalk_current, erp, "Legacy order and invoice integration", "SOAP / SQL") Rel(biztalk_current, erp_finance, "Legacy customer and finance sync", "REST") Rel(biztalk_current, wms, "Legacy fulfillment handoff", "FILE") Rel(biztalk_current, payment_gateway, "Legacy payment authorization", "REST") Rel(biztalk_current, carrier_tracking, "Legacy delivery status read", "REST") BiRel(biztalk_current, edi_gateway, "Legacy B2B document exchange", "AS2") Rel(azure_target, erp, "Target order integration", "REST / SOAP") Rel(azure_target, erp_finance, "Target customer and finance sync", "REST") Rel(azure_target, wms, "Target fulfillment integration", "REST") Rel(azure_target, payment_gateway, "Target payment authorization", "REST") Rel(azure_target, carrier_tracking, "Target delivery status read", "REST") BiRel(azure_target, edi_gateway, "Target B2B document exchange", "AS2") 
C4Context
    title Migration Context - BizTalk to Azure Integration Services
    Person_Ext(customer_user, "Customer", "Order submit and status checks")
    Person_Ext(supplier_user, "Supplier", "Invoice and product updates")
    Person_Ext(logistics_user, "Logistics Partner", "Shipment and delivery milestones")
    System(portal, "Portal", "Unchanged customer-facing system")
    System(erp, "ERP", "Unchanged core business system")
    System(erp_finance, "ERP-Finance", "Unchanged core business system")
    System(wms, "Warehouse Management System", "Unchanged core business system")
    System_Ext(payment_gateway, "Payment Gateway", "External payment processor")
    SystemDb_Ext(carrier_tracking, "Carrier Tracking DB", "External delivery confirmation store")
    SystemQueue_Ext(edi_gateway, "EDI Gateway", "External B2B queue")
    System(biztalk_current, "BizTalk Server", "Handles legacy integration workloads")
    System(azure_target, "Azure Integration Services", "Handles migrated and new workloads")
    Rel(customer_user, portal, "Submit order and query status", "HTTPS / JSON")
    Rel(portal, biztalk_current, "Current order API", "REST / SOAP")
    Rel(portal, azure_target, "Migrated order API", "HTTPS / REST")
    Rel(supplier_user, biztalk_current, "Current invoice and file exchange", "SFTP / FILE")
    Rel(supplier_user, azure_target, "Migrated invoice integration", "SFTP / Event")
    Rel(logistics_user, biztalk_current, "Current shipment status", "FILE / REST")
    Rel(logistics_user, azure_target, "Migrated shipment status", "REST / Event")
    Rel(biztalk_current, erp, "Legacy order and invoice integration", "SOAP / SQL")
    Rel(biztalk_current, erp_finance, "Legacy customer and finance sync", "REST")
    Rel(biztalk_current, wms, "Legacy fulfillment handoff", "FILE")
    Rel(biztalk_current, payment_gateway, "Legacy payment authorization", "REST")
    Rel(biztalk_current, carrier_tracking, "Legacy delivery status read", "REST")
    BiRel(biztalk_current, edi_gateway, "Legacy B2B document exchange", "AS2")
    Rel(azure_target, erp, "Target order integration", "REST / SOAP")
    Rel(azure_target, erp_finance, "Target customer and finance sync", "REST")
    Rel(azure_target, wms, "Target fulfillment integration", "REST")
    Rel(azure_target, payment_gateway, "Target payment authorization", "REST")
    Rel(azure_target, carrier_tracking, "Target delivery status read", "REST")
    BiRel(azure_target, edi_gateway, "Target B2B document exchange", "AS2")

Migration Focus

  • Current State: BizTalk Server handles the active integration workload.
  • Future State: Azure Integration Services takes over integration responsibilities.
  • Unchanged Systems: Portal, ERP, ERP-Finance, and Warehouse Management System continue as core systems.

Import-Friendly Notes

  • Keeps stable system names (Portal, ERP, ERP-Finance, Warehouse Management System, Payment Gateway, Carrier Tracking DB, EDI Gateway) across all sets.
  • Explicit current/target naming makes migration intent clear in repository entries after import.

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