ECO Depot - Empty Loading Bay

"Since there is only one loading bay, it must be empty before a delivery or collection can begin. It is the clerk's responsibility to notify the system when the bay is empty."

Normalization (active verb isolation, subject identification)
  The ECO depot contains only one loading bay.
  The loading bay must be empty before a delivery can begin.
  The loading bay must be empty before a collection can begin.
  A loading bay clerk must notify the system when the loading bay is empty.
   
Normalization (preconditions)
  A drum delivery can begin only if ... the loading bay is empty.
  A drum collection can begin only if ... the loading bay is empty.
   
Normalization (active verb)
  A loading bay clerk notifies the system when ... the loading bay is empty.

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Additional Drum Handling Concepts

Who unloads the drums from a truck in the loading bay?
  A drum handler transfers delivered drums from a truck into the loading bay.
   
What happens to the returned drums?
  A drum handler returns drums from the loading bay onto a truck.
   
How are the drums collected?
  A loading bay clerk gives a collection manifest to a drum handler.
  A drum handler collects drums from the storage buildings into the loading bay.
  A drum handler transfers the collected drums from the loading bay onto the truck.
  A truck collects a drum load from the loading bay.

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