Setting durations by use of formulas?

[Rowrowrow]

I have 2 tasks that have to take the same amount of time equal duration however have different differing amounts of work which are fixed. the tasks are placing concrete forms( a fixed area) and placing rebar (a fixed Tonnage). they both start at the same time and finish at the same time. the concrete formwork will always be longer. I would like to set the duration of the rebar to equal the duration of the formwork but do it automatically. fix the work and then let project tell me what my resource utilization is so that I can look at my manpower requirements.

Is this possible?

 

[zencalc]

If you link the two tasks with a finish-to-finsh relationship, then the start dates will not coincide. However, if you play with the resource available for the forwmwork (modeling), you should be able to manipulate the start date to get it to start at the same time. As always, the last thing to do is assign the resources.
Hope this helps...
Z.

 

[Rowrowrow]

I have done this set the ends to finish at the same time however as well I need them to start at the same time and have equal durations.

I want to see how the resources that I am applying to the various items peak over time. I have over 500 foundations and would like to do this automatically not have to open each one individually and adjust the durations to be equal

 

[PDQBach]

I think I know what you want but let's begin by looking at some other items.


First, your requirements contradict themselves:
"they both start at the same time and finish at the same time. the concrete formwork will always be longer."

If they start at the same time and finish at the same time then one cannot be longer than the other.

Second, you also want to do this for 500 forms!?!?! I'm just guessing here, but I expect you're using the same team over and over and over. Now you might have two or three teams but you're still moving them from one "form" to the next "form" to the next "form" etc. If this were my schedule, I'd have a task "Lay 500 foundations". That would be so easy to track, too. How many foundations done? 50? OK, mark the task 10% complete and see what the progress bar shows.

So ... second question first: what's the compelling reason and advantage for having 500 tasks instead of 1?

And first question second: Do they both take the same time or does one task take longer than the other task?

 

[Rowrowrow]

they both have to start and finish at the same time however they have different amounts of work. the foundations are each individual and different although there are some 20 differnt typicals there are variations in the typicals as well. I am looking at applying a pool of 60 men to the work but I have different professions on each work type thus different resources.

they take the same calender days but have different amount of work (which is a fixed quantity) in each one

 

[PDQBach]

If they have to start and finish at the same time then they should be one task with different people working at different %units or with different amounts of work (letting Project determine the %units).

But since you want to do it your way:

1. Create t1 and t2; assign resources to each and give each resource the amount of work you expect each resource to do.

2. Make sure both T1 and T2 are "Fixed work" type.

3. Let's assume that T1 is the one that "drives" everything and that starting T1 forces T2 to start and finishing T1 forces T2 to finish.

3a. Click on T1 Start date, Ctrl+C (to copy).
3b. Click on T2 Start date, click on Edit | Paste Special.
3c. Click on the Link radio button; click on OK.

Repeat the process on the Finish date.

You can see by the little triangle in the lower right corner that the date is a "linked" date but you cannot determine where the "linked" date source is.

You'll end up with a Gantt chart showing to two equal bars. You can link the tasks (SS) if you want but it's not necessary.

4a. To change the Start date:
Make sure the task type is Fixed Work. Change the T1 Start. That will change the T1 Finish and also change T2 Start and T2 Finish. It won't change the amount of work.

4b. To change the Duration:
Make sure the task type is Fixed Work. Change the T1 Duration. That will change the T1 Finish and also change the T2 Finish. It won't change the amount of work but it will change the Resource Unit allocation.

4c. To change the Work assigned:
Make sure the task type is Fixed Duration. Change the work assigned to the resources in T1. The duration will be held constant but the work will change.

5. Repeat 500 times.