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Hi friends,
I am in the planning group of a highway and infra project.Please give your valuable remarks on
what are the major considerations of calculating this project duration when the client
giving us a time period say approx 24 months..
Regards
Sunil
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Thanx Mr. Daniel Limson.
Cheers
Hi Tanveer,
We have 365 days a year (except for leap years like 2012), or 52 weeks a year and in the construction Industry especially on construction work sites, we normally work 6 days a week with 1 day off, on top of that every country has an average or minimum of 12 days (non working) holidays per year, so there you have it, that is where i got my 300 days.
Regards,
Daniel
Time chainage software are very limited software very bad at resource leveling if they figured it out, bad at details, bad at hundreds or thousands of activities that are not linear, bad at activities happening on the same location. Chainage software can balance production rates in the same way good CPM software can but they do it at the expense of considering resource leveling.
Time location software can tell you that for some segments the production rate as per length of road is different than for others if you model it right, that for the same segment lengths the volume of work might differ substantially. It is by working with resources and volume of work that you get the right schedule. Yes line diagrams are limited but still useful, better get software that can handle both.
In the following figure if line A equals line B, same location/volume of work, then both would be represented equally on a line diagram while a CPM will display and handle the details better.
These little graphs were good at the time of the K&E slide rule, if you know what it is. Good to work at a low level of detail. Unfortunately some dummy scheduling software cannot handle volume of work and this is why some people get lost with the efficient planning of their linear jobs. For serious earthwork planning the ancient mass diagrams by today standards are not good enough even on pure linear jobs.
A 10% difference in earthwork quantities might mean 1 MCM (million cubic meters) out of 10 MCM earthworks. What if the 1 MCM represents unsuitable material to be disposed and replaced from a borrow pit and in the middle you find out your plan did not considered it. This can spell disaster.
Do not fall in the trap of relying on nice diagrams just because they look good, can be nice looking garbage, but still garbage. Planning large earthwork jobs using only a scheduling software can be misleading. Use sophisticated earthwork software and communicate the plan using simple diagrams in combination to linear charts that can be developed from a CPM schedule capable of doing so.
For a start take a look at Dynaroad.
http://www.dynaroad.fi/pages/content/view/2/24/
I would recommend using such earthwork software for the planning and your favorite scheduling software for the communication at the site as well as for on the run adjustments.
Of course other types of linear jobs are not that complicated and can be planned without the assistance of specialized tools.
Best regards,
Rafael
Hi Sunil
The driving activity in a highway project is the cut to fill operation and productivity for that is the calculation of the Average Mass Haul.
If you do not know how to do that then you are in difficulty setting up the programme.
In any case you need to use a time / chainage software - P6 can't do it.
Best regards
Mike T.
Dear Mr. Daniel Limson
The formula you suggested to calculate the project duration ((100K X 1000m) / 600d). Is that some standard or driven from the given time i.e. 24 months. I am little confused where did the figure 600d came from because if we consider 12 month a year and 4 weekly holidays a month the number of nonworking days would be approximately 48 and for two years that would be (364d – 48d) 316d X 2y = 632d, if we consider 52 week a year and I weekly holiday the nonworking days would approx. be (364d – 52d) = 312d X 2y = 624d
Cheers
Hi Daniel,
Thanks a lot.It was so informative and valuable.
Once again thanks for your reply.
Regards
Sunil.
Sunil,
You need 3 things, Quantum, Production Rates and Resources.
Quantum - You need to have a good estimate (quantity) of the work involved.
Production Rates - If you have 100 kilometer of highways to build in 2 years (100k x 1000m / 600d) = 166m/day (this is the rate you need to achieved in order to complete the works in 24 months (now find out what is the current norm (standard rate) and compare to get and idea on how many teams or work fronts you need to achieved that rate)
Resources - Money, Materials, Labour & Equipment (resources only comes to the equation if there is a limit to the supply)
Best regards,
Daniel
Email: PPadmin@planningplanet.com
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