Dear Khun Thanapong/ Khun Pisit,
According to policy from engineering management that all MTO’s (both DB and material) shall be taken off from reliable tools either MTO-32 or PDMS model. MTO which is taken off manually due to constraint of time schedule or whatever reasons is not acceptable and must be avoided from now onwards.
For this reason, piping went through the MTO again and input data into MTO-32. We found that the quantity of DB from MTO-32 came up quite low comparing with counting directly from the 3D model. (it seems joints of flanges are not counted by MTO-32)
We did random check and found that the DB from MTO-32 is about 15% less than the actual quantity, therefore 15% was added to make it 100% completion in part of MTO-32.
In conclusion;
Step 1. First MTO + 20% to complete 100% (piping judges that the accuracy of first MTO for PPE is about 80%).
Step 2. Input 100% MTO from step 1. into MTO-32 and extracted the number of DB + 15% (to complete 100% in part MTO-32).
Please be informed that according to agreement form meeting between engineering and estimation department (Attended by Khun Pisit), the responsibility of piping engineering end up to this step. Another percentage of amounts for design growth and contingency shall be considered by estimation dept.
EPC cost break down will be revised accordingly.
One more thing to remind, the latest DB included fabrication and installation of cement lined piping. It requires special welding procedure, please ask subcontractor to quote carefully.