100%

Also useful for these activities you do not have historical records, something must be plugged in, averages from these references are better than pure imagination.

The following is a link to RS Means.

http://www.rsmeans.com/

an alternate source could be

http://www.constructionbook.com/

Please note it is a USA reference so it units will not be in the metric system. If you need a converter for units you can download one from the following link.

http://joshmadison.com/article/convert-for-windows

When you get the book please pay attention to the column that name the crew, at the end of the book you will find the crew details for manpower, tools and equipment for which the production is valid.

I still believe the best production rates are the historical rates, not the national average, not the average from other country but your own experience. Unfortunately too much emphasis today is on EV (Earned Value, an invention of US Government bureaucracy) of some value to Owners of little or none value to Contractors as we need the missing link, production quantities. EV to me seems like just budgeting and not true Job Costing.

After you get your true production rates I would recommend you to add about a 15% to your time estimate to account for the fact that during the duration of the activity not all resources will be available, a few on vacation, others sick, a few on other temporary assignments. Another approach could be to increase your resource requirements for time estimates and use a reduction factor for cost estimates. It is known that cost estimates are usually more on target than time estimates, time estimates tend to be optimistic.

Best Regards,
Rafael

We recommend our customers to create their own database on resource productivities on typical assignments. They differ for different companies, depend on people skills and experience. The resulting schedule should reflect the abilities of resources you have and not what others can do.
Creating these databases starts with the expert judgements and then is enhanced by statistics.
Resource productivities on the typical assignments is not the only database that should be created. You should also create databases for material consumption per volume unit of typical activities, volume unit cost for typical activities, resource workload on typical assignments and others if necessary. It is necessary to create typical fragnets library.
These databases will help to create corporate standards and are necessary for implementing portfolio or multi-project management. We have noticed that different companies use different internal norms and it is natural.

Gents

I guess there is few main tools we use to estimate durations.
1. Industry Standard - Like no hrs to install and connect a panels with x amount of I/O. or no hrs for a m3 concert to stand. Some activities is related to resource some not you have to determinate whether the activity is resource driven.
2. Common sence - Procurement/Delivery period of a Tx usually is 26 wks so you can make assumption without actual info. It is useful because not all info is accessable in the beginning of the project a guestimate is better no estimate.
3. Speak to the people (PM Supervisor, Designer) there is no better person to speak to other than the one who will carryout the task.

I guess what I mention above is common sence but since the intension of this, is to share knowledge. Hope it help!!

I hoped Sergio Monterisi’s posting may have shed some light on estimating durations...

Despite my name I don’t speak Italian so have to resort to ’Babel Fish’... This is a very rough literal translation for all those of you who are wondering what is going on!

Hello Valerio, apparently has had to me to enroll to an association of architects and engineers in order it makes you the crescent auguries old things. How you are? I write you from Boston, where I am in order to end my according to year to the Conservatory. You are well? Lathes in Puglia some time? I staro` li` nearly all the summer. If it goes to you, my number e` 347,6040868, while the email e` sergio.monterisi@libero.it. Not to often answer me on this news letter perche` not creed consultero` the a lot... I embrace, soon

My aplogies to all those who do speak Italian!

Arrivederci

David
dbordoli@burofour.co.uk
Visit Buro Four on the web

MR valerio,
Have you read the book? RS means has the complete production rates for all discipline. And I have copy of it. Try to Scan more. Or if you are are the construction site Start tracking / preparing your own production rates data which i think more efficient to use.

Best regards

I agree the Delphi Method is good for making estimates and gaining opinions (not of course limited to finding out about activity durations). I would suggest it is a bit of a ‘heavy’ tool to use for estimating activity durations if carried out correctly. The problem with involving third parties like that is that you have to retain their interest in your project sufficient for you to generate sufficient data. I doubt many ‘experts’ would be too motivated to contribute their time and energy to help produce activity durations for your programmes. I may be wrong and my apologies if you have used this method successfully.

David
dbordoli@burofour.co.uk
Visit Buro Fours NEW website Click Here

Hi Ali...

Im sorry that you seemed to have received so much anger in response to your question. I am surprised, I would have thougth that it is easier to say nothing than to say something unpleasant.

However, I hope this helps:

Quantities and Outputs: Use BoQ or take-off basic quantities then use work study or estimating outputs to covert the quantity to a time.

Specialist Advice: Best for specialist operations, seek the sepcialist/subcontractors advice, afterall it is they who will be carrying out the work.

Past Experience: What happened in similar activities on your last job.

Similar Work: Is this activity similar to another, if it is could their outputs/rates/times also be similar?

Data Generation: Durations based on building area, durations based on activity cost.

Guess: When all else fails take a guess, putting something down is often better than doing nothing at all.

Best regards
David.

The Planner or Planning Engineer is the person who would work out the duration of an activity. He would do this by using a rule of thumb rate i.e. xx m2 per man/machine hour such as available on this web site.

If he has the time he would speak to the specialist sub contractor who does this activity every day and obtain his advise.

Hope this helps