I have a microsoft project like calendar / gant database. I am currently trying to make an event in the calendar have the ability to be dependant on another event being complete before it can begin, like the predecessor function in MS Project. Once I do this, then I can sort the events by date, then by predecessor on the gant chart.

I have tried creating two fields, a predecessor field, which is a pull down menu off all of the events associated with the current project. The other field is a calc number field - predecessor number -

relation to self file via current project:: Predecessor number +1

This is the closest I've gotten, but filemaker won't let me do it because it can create a circular calculation. So, I would like to know, how do I do this without a circular calculation?

Thanks.

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Originally posted by Gildersleeve:

I have a microsoft project like calendar / gant database. I am currently trying to make an event in the calendar have the ability to be dependant on another event being complete before it can begin, like the predecessor function in MS Project. Once I do this, then I can sort the events by date, then by predecessor on the gant chart.

I have tried creating two fields, a predecessor field, which is a pull down menu off all of the events associated with the current project. The other field is a calc number field - predecessor number -

relation to self file via current project:: Predecessor number +1

This is the closest I've gotten, but filemaker won't let me do it because it can create a circular calculation. So, I would like to know, how do I do this without a circular calculation?

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This is definately circular. I am sure that you are going about this the wrong way.

I would start by simply using the "Predecessor" field to store the ID of the predecessor event. Now each event knows which event is it predecessor. Then I would simply append thier "Numbers" together. By number I mean some kind of logical number that they occupy in the sequence in the following format: Self by PredecessorID::Number & "." & Number.

Assuming that event #17 is preceeded by event #11, then the calc would result in 11.17, which can then be sorted.

However you will run into problem as each event will actually occupy 2 places in the sort order, once as a child of its predecessor and once for itself. This will cause problems.

I would suggest that you might need to add some kind of Parent-Child linking system like: cPC_ID = Parent::cPC_ID & "-" & RecordID.

This is similiar to what I described above, but you will get values like:

EventID Event Title

1 "Setup Project Files"

1-3 "Input Data Into Files"

1-3-7 "Print Reports"

2 "Schedule Meetings"

2-5 "Distribute Meeting Schedule Calendar"

If every event has an Task#, you can create a field DependsOn and define a relationship with DependentOn <--> Task#. The way you set the field DependsOn will depend on how your file is organized to create new task an link them to existing tasks. -bd