pc% for project- what are rules p3 depend on?

Member for

21 years 7 months

Pals



Interesting discussion...



Every system has its faults... We should find a system works for us.



Unit duration is good when activities are equiworth and similar nature ( like Civil Works, Installations) Curing should not be listed as an activity.



In case if we use cost in an EPC Elect.project, Civil may be 30% delay and if transformer arrives 1 month early we will be ahead of schedule...



Am I correct.





To measure physical progress Manhour may be the right unit.



Regrads

Yembee

Member for

22 years 8 months

do i detect a note of sarcasm there mimoune? :)



Tahir’s example illustrated the difference between physical progress and ratio of durations perfectly.



consider a simple concrete structure... say a pad footing.



Two activities:



Form/Reo/Pour Footing (Duration 7 days)

Cure Footing (Duration 28 days)



using the ratio of durations method for summarisation, once you pour the footing you will be reporting only 20% complete!!! 7d / (7+28d)


Member for

19 years

Dear Mimoun



Here is small tabular example for the same yesterday I had tried to explain in descriptive form, we plan to build a sleeper foundation A-1 and we try to roll up the progress up to foundation level from detail activities using duration and cost as weight factor

Weightage Progress

Description Dur Cost OD Cost Act FDN as OD FDN as Cost

Excavation/compaction 2 1000 12.9% 11.1% 100% 12.9% 11.1%

Lean concrete 1 1500 6.5% 16.7% 100% 6.5% 16.7%

re-bar Work 2 3000 12.9% 33.3% 100% 12.9% 33.3%

Formwork 1 500 6.5% 5.6% 100% 6.5% 5.6%

Inspection , go head pouring 0.5 200 3.2% 2.2% 100% 3.2% 2.2%

Concrete Pouring 1 2500 6.5% 27.8% 100% 6.5% 27.8%

Curing 7 100 45.2% 1.1%

Inspection and H.O to Mechanical 1 200 6.5% 2.2%

100% 100% 48.4% 96.7%

I hope this example is self explanatory, why the cost or resources widwly use to roll up the progress to summary level.


Member for

19 years

thanks Brennan, Tahir for your explanation.



sorry but i did not make myself clear, my question what is wrong with making the duration of activities as the weight factor for project summerization.



mimoune



ps ; Tahir hope the local subcontractors are doing well.

Member for

19 years

Dear Memoun

As explained by brennan that the duration base progress calculation will always in linear basis but it have some other impact such as if you are plan & monitor a civil foundation the duration foumula totally failed and base less such a simple foundation of 2 mtr cube may be require to construct in 7 days including excavation/dressing / compaction/formwork/rebar/lean and pouring but the curing period always 7 to 21 days but with a very less cost and manhours. In this case the progress representation on duration base totaly reflect the opposit to physical progress at site.

Cheers

Member for

22 years 8 months

Mimoune,



In my opinion progress should always be physical % complete.



Although there are arguments for and against it, I never use the autocost rule that links remaining duration and % complete.



At a summary level this is even more important. To really simplify it, consider a project that assumes a standard S curve for its progress. if you are using ratio of durations, the progress you plot will be linear.



Using the earned value method (resource units or cost) will allow you to not only summarise progress to the project level, but to any other level within your project you may need to analyise.

Member for

19 years

Hello



Brenna wrote



@Summary progress for a project can be calculated by ratio of durations (not advisable)@



can you explain more ?



mimoune

Member for

20 years 4 months

Forat,



In the projects i got involve with, it is the planner who calculate the percent complete of each activities.



Charlie

Member for

22 years 8 months

automatic calculation of % complete at an activity level depends on your autocost rules (RD linked or not)



But i think the question was partially addressed by your second answer Prabin.



Summary progress for a project can be calculated by ratio of durations (not advisable) or by earned value using resource quantities or cost.



you need to be careful using resource units that you are summarising one unit of measurement only (ie manhours) and not mixing them up (manhours, m3 of concrete, plant hours, etc).



For project level summary i would recomend cost be used.

Member for

20 years 1 month



P3 calculates % complete by calculating the percentage of actual duration spent wrt Total duration. i.e (OD-RD)/OD





For summerized activity, this can be set in three ways, i.e. in respect to Duration, Resources unit and cost.



thanks,



Prabin