Prevent users from directly creating a Customer record from a Lead record

There are instances when the user would like to ensure that the their customers under go all three stages of being a customer, from lead to prospect to customer.

To ensure that a customer would not skip the prospect stage, the user can create a workflow such as below:

 1) Create a custom entity field

     Type: Check box
     Applies To: Customer
     Display Type: Inline Text


2) Create a Workflow

     Record Type: Customer
     Sub Type: Lead
     Release Status: Released
     Enable Logging: checked


     Event: On Update
     Trigger Type: All

       
     Action 1: Set Field Value
       
         Trigger On : Before Record Submit
         Condition : Status = <prospect related statuses>
         Parameters:
           Field : <checkbox from step 1>
           Value : checked


      Action 2: Return User Error

         Trigger On : Before Record Submit
         Condition : <checkbox> = F AND Status = <customer related statuses>
         Parameters:
           Text: <desired text>