[marcd]

I am trying to set some tasks with fixed start times and calculate last dates for ordering with lead times. I have tried various dependencies, but they all try to move my task start time. If I lock it, my ordering task shows a project violation and asks me to unlock or move my locked task. Is there a simple way to work backwards in time from a fixed task?

[skwirl]

We have a feature request for the ability to plan backwards from a task, a.k.a. "as late as possible". I'll add another vote to it for you.

There is a way you could work around this by locking the start date of the second task, and setting up the dependency with lead time as before. When you get a violation, move the pre-requisite earlier, instead of following the violation's suggestion of moving the dependent later.

This wouldn't be very simple though. :(

[zosont]

can i put a vote down for this too please :)

[skwirl]

I'll add a vote for you zosont. :)

[marcd]

I have tried locking the 2nd task start and moving the pre-requisite task BUT.. there is a lot of manual trial and error to get around the violation without working out the dates manually. I guess what I am looking for is a start date CALCULATED from other tasks and/or PREQUEL dependencies from task to task.

The advantage of this could be used for task groups with regular time frames which one could re-use by copy and pasting into projects e.g. order placement from suppliers with constant lead times. Mostly, these are dependent on a project delivery date, say a milestone, which may move as a result of a client change. By changing milestone events (doesn't everyone else get this happening to them?) and PULLING other attached prequels a huge amount of manual changes can be avoided in project planning time.

Just a thought.. I hope others see the benefit and place their votes.

[Fritz Willy]

I've had luck putting the the milestone (like an ordering date) that I want to be a certain time ahead of a task AFTER the task and choosing a start to start dependency with a negative lead time (-4w).

[ac838]

Originally Posted by akwong

I'll add a vote for you zosont. :)

Please put a vote down for me too!

[skwirl]

Votes added. Thanks for the feedback!

[Danoz]

Please put a vote down for me as well.

[timesensitive]

Please add a vote for me as well.

I work in a lab and there are certain tasks that produce material which has to be used for the next task within a given number of days (or hours, in some cases). The consumption task definitely depends on the production task (finish to start, no lead time), but I also need the production task to depend on the consumption task (start to finish, or start to start, with negative lead time). In the current version, this leads to a violation (dependency loop), even though there is nothing logically incorrect.

Similar in concept, there are "waiting" tasks (no staff assigned) that take a certain duration, but cannot be left forever. This is like the classic "allow paint to dry" task in the tutorial, but with the added constraint that the freshly painted surface should not be exposed to the air for too long before applying the next layer of lacquer, lest it attract dust.

I really look forward to support for this kind of scheduling, and am also interested in more workaround ideas.
I'm currently demoing OmniPlan, and would have had no reservations about getting a license had these features be present. Now it's going to depend on what workarounds I can put into place.

Thanks!