Remaining duration

MAYBE %COMPLETE AND REMAINING DURATION ARE NOT LINKED, BY THE WAY THIS IS HOW IT SHOULD BE.

If you have linked %complete and remaining duration then whenever you edit one the other is recomputed according to the following formulas.

If you enter %complete remaining duration will be recomputed as follows:
REMAINING = ORIGINAL (1 - %COMPLETE) when there is no actual, otherwise
REMAINING = (ACTUAL/%COMPLETE) – ACTUAL

If you enter remaining duration %complete will be recomputed as follows:
%COMPLETE = 1 – REMAINING/ORIGINAL when there is no actual, otherwise
%COMPLETE = ACTUAL / (ACTUAL + REMAINING)

This method might create confusion, especially after you have actual from previous updates. Let say you have an activity with original duration of 2 weeks but after 2 weeks is 50% done and you expect to finish the remaining 50% in one week for a total duration of 3 weeks. If you enter these values into the above formulas you will get:
REMAINING = 2 /.5 – 2 = 4 – 2 = 2 weeks
%COMPLETE = 2 / (2+1) = 2/3 = 0.667= 66.67%
This mean you should have entered 66.67% to get 1 week for remaining duration.
REMAINING = 2 / 0.6667 – 2 = 3 – 2 = 1 week

The automatic linking of the two is one of the most common pitfalls of scheduling software programs. Cost loaded schedules are particularly susceptible to this scheduling pitfall, because the percent complete is tied to the earned value and cost to complete for each activity. Thus the percent complete must be accurately reported otherwise the cost reports will be inaccurate.

You have two options:

1. Keep the formula link and in the activity details enter either and the software will recalculate the other as per your last entry. Here formulas might confuse you.
2. Unlink the formulas and set each individually. Keep it simple and avoid any pitfall.

My recommendation is go with option 2, and then ask at the site, what is the remaining duration in work days after the update data date.

You will enter remaining durations for your activity duration computations and no change in %complete will be done at this point. You will enter %complete for your cost and EV computations and no change in remaining duration will be done at this point.

KEEP THEM SEPARATE.

Best regards,
Rafael

That is the way it is supposed to work. The software is not going to tell you how much work you accomplished (a reduction of remaining duration;) you have to tell the software. If you had 10 days remaining on 12NOV09 and do not change the status of your activity by indicating how may days of work remain on 15NOV09, the software has no other option that to assume that you meant to leave the status as having 10 days remaining.

CPM is more that a planning tool. It also allows you to track your progress and reassess you new situation based upon current progress. Just because you started an activity does not mean that you have continuously worked on that task, that you are making progress exactly as planned, or that you haven’t been delayed. At the end of the day on 14NOV09 (when you made you progress assessment,) you should have asked the responsible resource how many more days of work remained for that task. You should then enter the new estimate in the remaining duration slot.

By the way, just as a side observation; it is not 15NOV09 as yet. It is not even 14NOV09. If you are going to status your schedule a week early, you might as well save time and do the same for the next couple of years and hand them all in at the same time. Then you job will be complete and you can move on to your next assignment. Good luck!

Pls. how we can unlink the formula

Osama,

I no longer have P3 but check under Autocost Rules, it should be there.

You can do a search under P3 help for the keywords "auto cost", "link percent complete" and the like to find the way to the screen you are looking.

Best regards,
Rafael