Sunday, November 27, 2005

Impossible Relationships

As I began looking at adding finish-finish (FF) and start-finish (SF) relationship handling to Planner, I started to think about how to handle combinations of relationships. For instance, you could say that task C is dependent on tasks A and B, and this is fine so long as both are finish-start (FS) relationships.

Things start to get complicated if you try to combine relationship types, though, so I decided to have a look at MS Project to see what it allowed, and how it handled relationships that shouldn't work. Here's the result of my test, which became quite amusing after just a few minutes. See if you can follow the Gantt:



Now, this was MS Project 2000, so I don't know if they've corrected this behavior in more recent versions. Still, there's nothing like seeing this sort of thing in MS to boost your confidence level. Looks like whatever I decide to implement can only be an improvement.

1 comment:

Mybrid said...

Found your blog through google when looking for an answer for a problem I came across in MS Project 2003 and wondering whether you may have come across this problem yourself.

I have two activities: Activity1 and Activity2.
Activity1 has a 1 day duration and a predecessor that is Activity2-SF, for some reason this results in a start date of Monday (8:00am), but the finish date is Tuesday (8:00am) and not Monday (5:00pm) like I anticipated for a one day duration.

Have you come across this strange behaviour?