Documenting Precedence Constraints in SSIS

Just sharing a quick tip about showing the names of precedence constraints within an SSIS package. This is something I tend to do when the precedence constraint is based on something besides a normal "success."

Here's an example of where I have 4 precedence constraints in my SSIS package. Each precedence constraint references the value of a different variable in order for it to be allowed to proceed:

It's a bit easier to see what the package is doing at a glance if the precedence constraint annotations are displayed. 

The first precedence constraint contains an expression and a constraint. It looks like this:


Basically it is saying that, not only does the control flow task have to succeed, but a variable (being populated by the same task) also needs to have a count > 0 in order to be able to proceed. 

By default, the "ShowAnnotation" property on a precedence constraint is set to "As Needed." The canvas does show the fx symbol which means there's an expression placed on the precedence constraint. 


Since I wanted the package to be a bit more self-documenting at a glance, I changed the "ShowAnnotation" property to ConstraintName. And then I gave the constraint a good name like "If RowCount_ContractorEntity > 0" that would make sense when displayed on the canvas.


You might also like the output from the "ShowAnnotation" property called "ConstraintOptions."  It's even more specific.


There's also a "ShowAnnotation" property for "ConstraintDescription" but it doesn't work for me like name does, so I don't use that one currently.