This case document addresses the question stated in the title of the document.
The Employee Responsible for the contact cannot be changed directly. If the Account/Partner field is changed, then the corresponding Employee Responsible will be assigned to the contact.
1. Go to Account Management Work center.
2. Go to Contacts View.
3. Select a contact and select Edit button.
4. In the General tab, change the Account/Partner field.
5. The Employees assigned in that particular account will be shown in the Relationships tab of the contact with the Party Role Employee Responsible.
KBA , SRD-MD-BP , Business Partner , How To