Ladder relationship and critical path

Hi Balu

Why do you want to fiddle your programme to make an articial critical path?

There are many threads on ladder programmes for you to search your answer.

Basically ladders are good for production line factory programmes with lots of repetion - they are of little use in construction.

Best regards

Mike Testro

Hi

Use of ss and ff links together holds good to shift non activities to crticial

Dear Balu,

You can do that by making their float = 0. Any way you can think of achiving that.

The activity will become critical if you do not work on it at the right time and when its float is zero. You might want to try to change the starting date to an earlier date. This will make it become critical faster.

With kind regards,

Samer

Hi Samer

Surely you need to make the starting date later for it to become critical sooner.

Another way is to delete all links and put a must end by flag on every task.

I re state - it is bad practice to fiddle a programmes critical path.

Best regards

Mike Testro

hi samer , i got a difficult puzzle as a CPM network if u r interested i can send it to u via email to solve it if u can???

Bala

If u want to show the activity as a critical path put the constraint must start. it will make float to 0

Hi Mukunda

And then what happens to the critical path.

Never use any constraints at all.

Best regards

Mike Testro

Hi to all

Mandatory start constraints set both early and late dates equal to the specified date.This constraint tends to overwrite all calculated results in the schedule

I agree not to use constrains at all. Otherwise it’ll break schedule logic.
I suggest you should change the criteria of critical path.
Put total float <= 5 days or 10 days (instead of default total float <=0) In that case all near critiacl activities come to the critiacal path and become "red" on the gantt chart. It is also give you some additional time (Float) to control activities before they become really critical.

Hi Sergey

Welcome to Planning Planet.

We look forward to further contributions.

You may be interested in the Spider Software threads.

Best regards

Mike Testro

In terms of not using calendar-based constraints, I agree with Mike 99.9%. The one exception is if a constraining factor is TRULY calendar driven (e.g., for some reason, you HAVE to wait for the full moon, or for a comet to reach a certain point), and you know EXACTLY when that will occur.

But if you DO use constraints, two rules to follow:

(1) Input each constraint separately, one at a time, and see what the impact is. If you can’t live with the impact of a specific constraint, you’re going to have to figure out a way around it.

(2) FILTER OUT all constraints (and LOEs!) when doing what-ifs and other schedule analysis. The constraints will constrain (!?) your (and the software’s) ability to push things around and see the impact.

For example, constraints and LOEs will erroneously change the drag calculations in MSP (and I suspect in Spider Project -- Vladimir?).

Finally, as has been said, the issue of playing around with float is a dangerous game. And, as for highlighting all activities with less than a certain amount of float, sure, do that if it reminds you to keep track of paths with limited float.

But ultimately, what’s important to project completion is drag -- if the second longest path has 5D of float, that means the CP tasks at that part of the schedule can have up to 5D of drag. That’s crucial info -- use it NOT to justify "pacing" the project and letting the second longest path slip by 5D, but to pull in the longest path by 5D or more. And then iterate the process on whatever activities are now on the longest path.

This optimization process is crucial -- if my project MUST be completed by June 30, I’d much rather have a schedule where the longest path is scheduled for completion June 10 and there are 12 other paths with less than 5D float than a schedule where the longest path is scheduled for completion June 29, and the next 12 longest paths all have 15D - 20D float. And that’s how you generate your schedule reserve.

Fraternally in project management,

Steve the Bajan