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Estimated completion time

17 replies [Last post]
Fri, 2005-09-09 04:45
steve willis
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We all know that Computer schedulers work out the estimated completion time of a project .But for piece of mind can anyone tell me a simple formula that you can use to work it out.
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Replies

Sat, 2005-10-15 13:33
#1
Wilmore Makonese
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GOOD PLANNING CLIVE, THAT’S THE ANSWER TO THIS QUESTION AND OF COURSE THE OTHER SUMMARISED BIT BIT FROM SAKAMURA... FROM MALASIYA.

OR THE VERY SUMMARISED: EXPERIENCE & EXPOSURE - WHICH WILL SHOULD GIVE YOU ALL THE RATES & TIMESCALES NEEDED TO COME UP TO COME UP WITH AN ESTIMATE.
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Sat, 2005-10-15 07:43
#2
Oscar Wilde
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Here here clive
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Fri, 2005-10-14 02:14
#3
Clive Randall
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I am getting the urge to break into capital letters.

Yes the Client decides the Project duration sometimes based on factors beyond those the contractor is aware of.

However read what i said earlier

At the time of tender it is the planners responsibility to make sure the contract period can be achieved and allow sufficient resources to achieve it even if these resources are un-economically utilised. He must advise the estimator what he has done.

If after all this he still cannot find a way to achieve the contract period he should advise the overun so that the estimator can allow LDs .

A very foolish Company assumes the period is achievable without checking at the time of tender.

As for claiming an EOT this has little to do with whether the contract period was sufficient. You will certainly NOT get and EOT because the period proves not to be sufficient.
at a later date.

Carpe Diem (or similar)

If you are saying because of insufficient information it is impossible to check then you can either qualify your tender or make educated assumptions. These require experience and this is where your senior planner or planning manager will come into his own.

kind regards

Clive Randall
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Thu, 2005-10-13 23:47
#4
haslan abdrahim
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i think client always imposed completion of the project during tender stage and normally the contractor will schedule the projet to complee within the time imposed by the client in that way chances to win the job is higher. in reality during construction contractor realizes that the time given is too short and endup of applying for eot.
so any comment?
regards
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Wed, 2005-10-05 00:18
#5
Rolyn Jalea
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hi,

Sometimes it sad to say that by the time a planner goes to work on a schedule, the planned start and finish date is already approved in the contract. There’s no way he can do about it but to maximize as much as possible the alloted duration based on the contract.

Regards,

Rolyn
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Sun, 2005-10-02 10:40
#6
Zq qz
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EXPERIENCE .............. AND EXPOSURE ........
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Thu, 2005-09-29 06:42
#7
Charleston-Joseph...
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Hi Clive,

In the planning engineering way, the approach in estimated completion time is reasonable.

In reality, client do have the final say on the project completion time.

Some project duration during the tender stage maybe unrealistic, but at the end of the day, what project duration agree and stipulated in the contract is an obligation of the contracting parties.

Cheers
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Thu, 2005-09-29 02:42
#8
Clive Randall
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Sorry dont agree either with you Mr Zang or Raja
This to me is the planning rub
We allow clients to determine what they want and therefore programme for that whether it is possible or not
thats fundamentaly flawed and if not picked up leads to contractors paying damages or acceleartion costs which they do not have in their budgets.
I believe that a rule of thumb exists.
However if you really want to know how long it will take i would suggest the following. Work out when you will have the builders work drawings cast ins etc. Work out how long it takes to do a floor (not so easy but the subject of another thread), multiply that by the number of standard floors, add in the non standard floors, see when you can start the cladding (not just on structure status but also on material delivery), Schedule when you can do the finishings. Allow 4 months for the roof top plant rooms a further 2 for commissioning.
Press the button and see where the path lays on high rise it will be up the structure through the toilets, lifts and plant rooms and out through the front reception and external works.
If it dosent sit with the contract period review the critical path and see what you can do with it. More cranes more people, more formwork. Concentrate on the structure as it usually the easiest to accelerate (less trades). Having done all that see where you are. You would be suprised how little difference all the manipulation you do makes even when you try to manipulate the critical path.
Remember to take a day off on a floor cycle costs a fortune and on a thirty storey building saves you only a month.
Also remember factors that despite money or time cannot be accelerated, offshore deliveries, concrete strength gain, flushing of mechanical systems, anything to do with Govenment.
If the answer is not what the client wants to hear add the damages into your price and tell him it can be completed in his timescale.
Whatever you do dont believe the client has the right timeframe until you have checked it and taken appropiate measures to ensure it can be achieved.
You may find that you can do it quicker than he wants it so you can reduce your prelims. Thus winning you the job.
Thats what planners are for. Well thats what i think there for to prove beyond a reasonable doubt how feasible the time element of a project is.
Despite all this I believe there is a rule of thumb for how long a building will economically take to build.
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Thu, 2005-09-29 02:20
#9
Raja Izat Raja Ib...
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Hi Mr Zhang,
If u were contractor, 100% agreed, but for client maybe they have to think The best date to Come out with the product. The best date is when the product price at that time rising Up.
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Thu, 2005-09-29 02:14
#10
Zhang Haixiang
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the completion time highly depends on the requirements of the client( time & budget),so there is no such a formula

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Thu, 2005-09-29 00:29
#11
Clive Randall
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Steve
I reckon Sukaraman is spot on
The rule of thumb is pretty close to the outurn time for a building
Obviously u need to conside and requirements from Government authorities etc
For those who dont believe there is a rule of thumb have a think about how a project period contract period is arrived at. Usually by a client who knows what he wants and approximatly how long it has taken before.
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Mon, 2005-09-12 02:42
#12
Raja Izat Raja Ib...
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use production rate per square meter and apply to the design u can get:
a. estimated resource
b. estimated manhours
c. estimated cost
d. estimated scedule

this production rate, u can extract from previous project and to get good productivity, u have to analyse closeup report(lesson learn)...if u have.
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Mon, 2005-09-12 01:50
#13
Sukumaran Subaram...
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Steve,

As for highrise building:
1) Get the productivity for one floor i.e. for structural works. Use this productivity rate and calculate the overall structural completion date.
2) Check when the contarctor can start the M&E and Architectural Works. The contractor shall be able to complete the work approximately six months after the structural completion date (depend on size of the project).
3) Then calculate the duration for External Works, Final Cleaning and Hand Over.

HTH.
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Fri, 2005-09-09 04:54
#14
Edgar Ariete
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Hi Steve,

May I suggest: A) Strategy + Practicality + A lot of Prayers....

You said Estimated... that’s a GUESS...

If you want it accurate...You measure it. Use any machine.


regards,

Edgar
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Fri, 2005-09-09 06:36
#15
Charleston-Joseph...
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Hi Steve,

There is no such things as simple formula in arriving at estimated completion time.

The danger of using simple formula is the consequence of your professional reputation.

In my younger days, i did hear a lot of old folks guessing the estimated completion time base on their previous projects experience and interpolating those experiences with the projects at hands. They just remains guess. There is no substitute to hard work and engineering approach to arrive at estimated completion time.

I hope this will help you going somewhere

Cheers,

Charlie
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Fri, 2005-09-09 07:00
#16
William Cormack
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I had a quick look at the APM’s EV Guidlines and it gives the following equation:

Forecast Completion (In weeks from original project start) = Original Completion/SPI.

It’s also worth looking at Appendix D of that document.

I make no comment on the validity of these formulae.
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Fri, 2005-09-09 07:10
#17
Katalin Hovanyi
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Haliho,
The reason for the risc analisys that nobody can be sure. Formerly the fortune tellers did the job but we became modern and the planners got this thankless task. Steve, an advice. Use as much Finish to Start connection as You are able and when the project ongoing and whenever You get the resources and the workplace go paralel. In that case, MAYBE (it is a big maybe) You can get the originally estimated dates (or a more or less near one).
Best Regards
Katalin
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