Question on multiple predecessors

Michael G. · 04/01/19

Hello!

When using 2 predessors for one row, smartsheet calculates the later start date.

How can I manage to get the earlier start date.

For me it sounds like a common requirement. Start as early as necessary to meet 2 alternative deadlines ...

Kind regards

Michael

Michael G. · 04/01/19

Better example :-)

Jennifer Greenough · 04/01/19

Hi there,

I suggest you take a look at this discussion regarding predecessors - logic and limitations when it comes to project planning. This is not a Smartsheet article, however the issues discussed are broadly applicable to scheduling tools such as Smartsheet. As far as I'm aware, the only way to show the situation you describe above is to include both items, and then to switch between them as predecessors to show the potential scenarios. The project plan would include the worst case scenario by default. As you manage the project, you would retain the appropriate predecessor to reflect the reality of how things went.

Jennifer

Paul Newcome · 04/01/19

Have you tried adjusting the Start-to-Finish/Finish-to-Start and/or the Lead/Lag times?

Michael G. · 04/02/19

Hi Paul,

in example 2 you can see all Start/Finish options (A = Start (in German "Anfang"), E = Finish ("Ende")). So no chance!?

My last idea was to use a calculation of the earlier date (IF ...), but start date does not allow a formula.

Regards

Michael

Michael G. · 04/02/19

Hi Jennifer,

thank you, but from my point of view my requirement is a basic one to a professionell project management tool.

Regards

Michael

Paul Newcome · 04/02/19

Thank you for the translation. The German language is on my list to learn, but I haven't quite gotten there just yet.

Smartsheet is calculating under the assumption that Predecessors are required. So even using Start to Start, the task cannot be started until all predecessor tasks have been started. According to your screenshots, all predecessor tasks will not be started until 01.05.19 which means that any further tasks cannot be started until then. The reason you are getting earlier start dates is because of your negative lag time.

If row 2 does not have to be started before you can start row 3, then row 2 isn't actually a predecessor for row 3.

Does all of that rambling make sense?

Michael G. · 04/02/19

For us it makes sense: We are using project plan templates for fairs/exhibitions. There are 2 customer-driven milestones and it is not sure, which one is earlier. A dependent process has to start a specific time before the earlier one ...

Thank you for your participation

Paul Newcome · 04/02/19

Happy to provide input. Hopefully you get everything you need squared away. I personally don't often use the dependency settings because of the limitations.

Question on multiple predecessors

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