Dependency in deleting components like field etc.

 when you want  to remove a field in a solution. 

When you try to delete it from unmanaged solution you will get an error that it is dependent on other items like workflow to any. (click on filed - option- check decency)

Open the workflow, Clear the value set by the field and publish. 

and do the same for other dependent form or items. 

and then try to delete it.