MAN HOUR ESTIMATE

No, there is no such thing as an "International Standard" for estimating piping man hours.

Each company recorded or not has their own unit of measure based on how they are organized and how they operate.

Below, I have given you some data showing factors for the home office hours to do piping engineering and design work. Regardless of the type of project, this type of data reflects only part of the piping cost picture. The other part of the home office hour picture is the hourly rate to do this work. This hourly rate depends on where you do the work and the level of expertise (training, experience and supervision) the people have.
Where you have the work done includes the country, the city and the company. If the work is done by one of the top, first class U.S., U.K. or other European engineering companies in one of their home engineering offices you will see fewer hours but at a higher cost. This same company might choose to out-source the work to one of its overseas partners or subsidiaries where the work may need twice the number of hours to achieve the same level of quality. These hours, however, will be at a rate that is far below the U.S. rate. So you need to know where the work will be done and adjust the number of hours and the rates accordingly.


PIPING ESTIMATING DATA

The following data is a summary of the averages of actual data from 4 representative projects conducted in the late 1990's. The smallest was $9,000,000 and the largest was $60,000,000.


Category Data
Average Total Project Hours = 126,055
Average Total Piping Hours = 33,810
Average Percent Total Piping Hours vs. Total Project Hours = 26.82%

Average Project Line Number Count = 391
Average Project Isometric Count = 1,403

Average Total Piping Design Hours = 26,190
Average Total Piping Material Engineering Hours = 1,854
Average Total Piping Material Control Hours = 800
Average Total Piping Stress Engineering Hours = 1,528
Average Total Lead Piping Engineer, Dep't Prorate & Admin. = 3,438

Average % Piping Design Hours vs. Total Piping Hours = 77.46%
Average % Piping Material Eng. Hrs vs. Total Piping Hours = 5.48%
Average % Piping Material Control. Hrs vs. Total Piping Hours = 2.37%
Average % Piping Stress Eng. Hrs vs. Total Piping Hours = 4.25%
Average % LPE, Dep't/Admin. Hrs vs. Total Piping Hours = 10.17%

Average Total Hours per Line Number = 86.47
Average Isometrics per Line Number = 3.6
Average Total Hours per Isometric = 24.11 appropriate estimate.



There are still many other factors that will impact the Total Installed Cost (TIC) of the piping for a project. These other factors include the pipe material, the fabrication, the NDE requirements, the logistics, the final installation, the testing and any pre-start-up preparation.
• Pipe material: This is a multi-part issue. There is the metallurgy itself (carbon steel vs. alloy. There is a big difference between the wide ranges of materials that might be used. With-in the given metal there is then the pipe size which affects the cost and finally there is the pipe schedule (wall thickness) which not only affects the initial cost of the pipe but it also affects the cost of fabrication.
• Fabrication: The fabrication of the piping systems is either done in a remote “shop” or is done at the job site. Fabrication at a shop is normally done at a cheaper cost than at the job site. The cheaper cost is the result of the ability to use the jigs, fixtures and automatic welding capabilities that are available in the shop. For this reason most projects choose to maximize the shop fabrication of most piping systems. However shop fabrication is only possible up to a point. You will still have to install the piping spools and make the final field welds.
• NDE requirements: NDE stands for Non-Destructive Examination. Depending on the applicable Piping Code requirements different levels of NDE is required for welds in piping systems. NDE is another cost additive to the overall picture.
• Logistics: This relates to the distance and the ramifications involved in the issue of point of fabrication-to-point of installation. Everything from distance to politics to weather can and will affect the logistics issue.
• Final installation: This issue is also complex. It is influenced by the job site location and the availability of qualified personnel. The job site might be in the arctic or it might be in the middle of the desert. Both of these bring unique problems and will add to the cost of the final project. Final installation also includes any heat tracing, insulation and painting. In some projects it may include dangerous and very costly “Tie-Ins” (Hot-Taps) to active systems.
• Testing: The applicable Piping Code will dictate the testing requirements. The client may also require additional testing over-and-above the Code that will also increase the cost.
• Pre-start-up preparation: This is a category of costly work that may include special cleaning, pickling of the pipe or other internal pipe surface preparation.

I would suggest that someone in your company has data on all or most of these categories for at least 10 past projects. However you will need to determine, ahead of time all or most of the factors. I recommend that you define a very clear and detailed scope of work on which to base your estimate.

You wrote:
"provide us some detailed structured view of the estimation philosophy followed in current 3D platform scenario"

So you want the actual "Estimate Form" from some company. Is that right?

abhijit
Please go here:
www.pipingdesigners.com/Tools%20 ... on%201.htm

and read section 2 (part a and b)