A workspieces problem has two parts, the workpiece and the operator.
The operator is a person using a computer to control the workpiece.  
The workpiece is something inside the computer that changes only when the operator changes it.
Some examples are a spreadsheet, UML diagram, or word processing document.

The WorkpiecesFrame is ideal for object-oriented programming, and in fact
classic object-oriented programming seems designed for it.  Although object-oriented 
programming is used for all kinds of ProblemFrame s, it is most natural for this one.  -RalphJohnson