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Early Finish and Late Finish not matching and total float has negative decimal float

9 replies [Last post]
JOHN GEORGE
User offline. Last seen 26 weeks 4 days ago. Offline
Joined: 29 Mar 2010
Posts: 11

Situation:

I have attached below a snap shot of the first page of a baseline schedule submitted by a contractor. A Quick glance while reviewing the schedule shows that they have used a calender having different working hours during various months based on Ramdan reduced work hours etc. The default calender assigned in the project level is the same.

A must finish by constraint is assigned on 31-Aug-14 at project level.

One of the activity as seen in this picture "Mobilization Works" has been given an original duration of 14.50 days.

There are milestones with invalid relationships as per scheduling report; probably due to assigning FS predecessor relationship to a Finish Milestone etc.

Questions:

Are there any reasons other than the above for having a project late finish date earlier than the project early finish date, ,having fractions in total float?

Is it required to impose a must finish by constraint before starting the update process?

1629
02_early_and_late_dates_review-total_float.jpg

Replies

Sunil Babu
User offline. Last seen 5 weeks 4 days ago. Offline
Joined: 8 Nov 2010
Posts: 156

John,

Dont put must finish constraint, check your relations also the calendar assignment.

Regards

Sunil.

Mike Testro
User offline. Last seen 5 days 10 hours ago. Offline
Joined: 14 Dec 2005
Posts: 4393

Hi Charlie

Three things:

1. Welcome to Planning Planet

2. Next time place your topic in its own heading - not tucked under another.

3. Check your calendars.

Best regards

Mike Testro (Moderator)

Charlie Daniels
User offline. Last seen 4 years 46 weeks ago. Offline
Joined: 29 Nov 2013
Posts: 12
Groups: None

Good day All,

 

I have a few issues which I need your assistance with please.....

 

1. I have a schedule consisting of about 3000 activities so it is quite an exercise to analyse when there are inconsistancies.

When I imported this program to P6 The start and finish dates don't quite match the baseline dates, the original durations don't match the remaining durations, (if the activity is compared to the baseline bar it's not the same and in a schedule with this many activities it has must have a significant impact)

I have done the exercise of aligning the durations and end up with a matching start and finish date to the baseline, but a negative lag of 25days.

When I hit the schedule button (F9) the the program finish date falls back and ends up with a positive float of 23 days.

 

How can it be different to the Baseline?

 

I have tried a number of angles to find out what is the problem, I have even Put a mandatory constraint on all activties so that float and variance all = 0, BL Start and finish = start nd finish and at the end of the program I still get some negative float and still end up with this negative 25 days float but all the dates are aligned with the baseline?

 

This programm was originally developed in MS project and imorted to p6. could this have something to do with it?

 

I don't know what to do next, pulling hair out now... ;-)

 

Not even sure my question makes sense at this stage.

 

Please any suggestions would be appreciated\

 

Thanks

Charlie

 

 

 

K L KAMESWARI AK...
User offline. Last seen 5 years 49 weeks ago. Offline
Joined: 27 Apr 2013
Posts: 8
Groups: None

Dear Sir,

I am also suffering similar Problem.

  1. I have developed the baseline schedule, assigned and maintained the baseline and put a constraint to finish on 14thFebruary 2014.
  2. Then I have created the Financial period values starting from Wk-16 of 2013 to Wk-07 of 2014
  3. Then I have inputted the actual Man hours in the Schedule using Store  Period Performance.
  4. After Scheduling the project to current date,   the Finish date of the project is going to the week of May 2014 where as my Baseline Schedule finish Date is 14thFeb 14.
  5. Please explain why the Early Finish date is going beyond the Project Finish Date of 14thFebruary 2014 and how to fix the Early Finish date to 14thFebruary 2014 .
JOHN GEORGE
User offline. Last seen 26 weeks 4 days ago. Offline
Joined: 29 Mar 2010
Posts: 11

Thanks Raymund and Pranab

Raymund de Laza
User offline. Last seen 1 day 52 min ago. Offline
Joined: 23 Nov 2009
Posts: 698

Questions:

Are there any reasons other than the above for having a project late finish date earlier than the project early finish date, ,having fractions in total float?

Is it required to impose a must finish by constraint before starting the update process?

 

John,

There is issue on Time because duration are in fraction. Check the Dates Time.

Must Finish constraint shall be assigned as the Project Contract Completion Date during preparation of Baseline.

Pranab Kumar Deb
User offline. Last seen 1 year 13 weeks ago. Offline
Joined: 23 Jan 2007
Posts: 285

Hi John,

A SS relationship with the Start Milestone and FF milestone Would Finish the project ont he same time for both Early and Late dates. Otherwise the milestone would either move to the previous "minute" or the "minute" just after the project finishes.

regards

Pranab

 

JOHN GEORGE
User offline. Last seen 26 weeks 4 days ago. Offline
Joined: 29 Mar 2010
Posts: 11

Hi Kevin

Thanks for your reply.

As I Know, A Finish Milestone has only a Finish Date and cannot start; assigning a predecessor FS means the finish milestone is supposed to start after the predecessor is finished. A FF or SF relationship is always logical for a Finish milestone.

I removed the fraction in the duration of the actvity mobilization and made it 14 d instead of 14.5 d, this removed the fraction in float.

When i removed the must finish by constraint, the negative float also disappeared; probably because the project must finish by constraint should have been set on 01-Sep-2013, one day after the planned finish date. This is a change noticed from P3 to P6. P3 used to accept the same dates for project finish and must finish by constraint.

 

 

Kevin mains
User offline. Last seen 6 years 14 weeks ago. Offline
Joined: 30 Sep 2004
Posts: 5

Hi John

Firstly I'm pretty sure you CAN have FS logic with a finish milestone.

You do ideally have a finish constraint on the last activity or the project so that this will drive the float to a required completion date.

The "late finish date earlier than the project early finish date" is being driven by the logic I would assume, you need to review the longest path. Fractions in the total float is only due to the format of the time units! 

My worry would be that they have issued a plan that has negative float?? Which is saying that they don't think they can finish on time albeit only a few hours late!! I'd like to see some float in my programmes!!

 

 

Kevin