Merging and Unmerging Cells

Enterprise Architect has a useful feature that allows cells to be merged. It is only possible to merge input cells and not output cells and so these three conditions must be met to be able to merge two or more cells:

• The cells must all be input cells
• The cells must be contiguous
• The cell must have the same value expression

Under these conditions it is possible to merge cells to try and simplify the table and make it easier for non-technical and technical audiences alike to understand. In the decision table in the diagram we can see that there are two groups of cells that meet the conditions and can be merged, namely:

• The two cells where Risk Data.Age < 18 and
• Three cells that have Risk Data.Age defined by the interval [18..55]

These options are available from the DMN Expression window toolbar. In the case where there is the possibility of more that one merge, there is an option to merge just specific cells or to merge all cells.

Some Decision Modelers might prefer not to do this, so it becomes a matter of what presentation best suits an audience. Enterprise Architect can assist here because it conveniently provides an un-merge option as well, so if someone has previously merged a number of cells this action can be undone. Clearly this can be toggled to suit different audiences.