Dynamically executing a child pipeline using a single Execute Pipeline activity with a variable

As far as I know, this is not possible.  The pipeline must be selected at design time for validation purposes.

Workarounds:

• Use a Switch Activity to call different pipelines based on the value.
  For example:
  Master Pipeline
  - Lookup (get caseValue)
  - Switch Activity (evaluate caseValue)
  - Case = "LoadCustomers" > Execute Pipeline: LoadCustomersPipeline
  - Case = "LoadOrders" > Execute Pipeline: LoadOrdersPipeline
  - Case = "LoadProducts" > Execute Pipeline: LoadProductsPipeline
  
  
• Create a generic child pipeline that handles different logic based on a passed parameter.
  For example:
  MasterPipeline
  - Lookup (Metadata)
  - Set Variable (taskType)
  - Execute Pipeline (GenericChildPipeline, passing taskType)
  
  GenericChildPipeline (parameter: taskType) 
  - Switch
  - Case: LoadCustomers > Customer Copy Activity
  - Case: LoadOrders > Orders Copy Activity
  -  Case: LoadProducts > Products Copy Activity
  
  
• Metadata-driven with using a Web Activity to trigger the pipeline dynamically via ADF REST API.
  For example:
  MasterPipeline
  - Lookup (Get Metadata - includes pipeline name)
  - Web Activity (Trigger Pipeline via REST API - dynamic URL)
  
  
• Orchestrate externally using Logic Apps, Azure Functions, or custom scripts.