Engineering

Feasibility Study, in case required by a contract, is the investigation of technical and economic aspects and available alternatives in execution of a potential project in order to find out the best approach to achieve the general goals of that project in terms of technical feasibility, social and environmental acceptability, and economic justifiability.

Some major considerations in a Feasibility Study are:

Investigation and determination of available project locations in view of expected feed and product and utilities types and quantities, and their projected price
Technology alternatives
Transportation bottlenecks during project execution and production
Social impacts
Environmental impacts
Finance sources and Costs Involved
Economic return of the project during its life cycle based on rough estimations (+­ – 20-30 %) Capital Expenditures(CAPEX) and Operation Expenditures (OPEX) of the project alternatives, and comparing it with other investment alternatives in terms of “Opportunity Costs”.

Conceptual Design starts by general overview of the most techno-economically relevant way(s) of doing a project using the conclusions of the feasibility study.

In Conceptual Design the major focus is on providing a more detailed technical description of the best alternative in doing the project.

This is done by defining the project plot location, block flow diagram, process and non-process units summary description, feed and product and utilities definition and general requirements with their approximate quantities, based on process simulations (if deemed necessary) and/or using in-house historical data on similar projects.

Generally speaking, the objective of project Owners in asking for FEED (also sometimes called Extended Basic or Advanced Basic Design) is to develop the Basic Design to a more detailed level in order to provide:

a relatively accurate quantitative basis for EPC Tendering of a project;
achieving a relatively more solid and uniform basis for EPC contractors realistic price offerings for a project;
avoiding too much risks/contingencies included in EPC contractors prices, leading to inflated price proposals.

In other words, Owners by requiring FEED from the Basic Designer spend several more million Euro’s or USD’s but may gain up to several hundred million Euro’s or USD’s depending on the project size. That is why the practice of FEED has become so popular in the past two decades– parallel with advances in 3D modeling, among other computer based technologies.

Also, by doing FEED, more extensive information and specifications would become available that makes detail engineering and procurement by an EPC contractor more straightforward, less time consuming (especially for long delivery items), and more tuned to the Basic Designer’s /Licensors’ requirements.

The major outputs of FEED stage used in cost estimations by Owner and /or EPC Contractor are as follows:

All the major bulk material quantities (MTO’s –Material Take-Off’s– e.g. Piping above 6”, primary Steel Structures/concrete works, civil works/buildings, etc.) could be made available with a certain level of coverage (let us say, 70-80 % of the total) based on 3-D model further development and other calculations at this stage;
All the equipment and packages are adequately defined for price inquiries/estimations;
All the major weights/quantities (BOQ’s – Bill of Quantities) needed for civil/underground construction works, as well as for mechanical erection estimation, are approximated with a good level of accuracy.

Important Note: In some cases (especially in Iran), the EPC Contract is tendered and awarded before the FEED. However, the EPC contractor is obligated to deliver a FEED package for Owner’s approval, usually by a third party company of proven references especially in Process/Safety/Layout design of similar projects in terms of scope, scale, and complexity.

The Owner’s objective in such cases is, on the one hand, to feel assured that EPC contractor’s subsequent detail engineering, procurement and construction activities would be based on solid foundations with no major variations; and on the other hand, long delivery items could be ordered earlier in the project.

Detail Engineering is the completion/finalization of Basic/FEED stages with the overall objective of providing all the necessary finalized documents and drawings for purchase of equipment and material and their construction/ installation works at site, leading to successful operation of a plant according to the contractual requirements of a project.

This objective is realized by the following main activities and outputs:

Developing PDMS based 3D model of the plant in milestone progress stages towards its completion by incorporating all the pre-defined finalized information, mostly related to piping and equipment, but also including civil/structure/building as well as instrumentation/ electrical (including safety) information.

The information provided in 3D model includes the precise physical characteristics of the plant and its components such as location coordinates, dimensions, routes, access ways, etc. as well as tag numbers and other relevant data available as input or output of the PDMS system.

Issue or review/approval of documents and drawings leading to procurement of material and equipment such as calculations, data sheets, drawing and specifications, lists, procedures, inquiries (material requisitions), Technical evaluations of vendor proposals, vendor document checks, shop inspection procedures and reports, etc. Some of this procurement information is the output of the 3D model, e.g. Piping MTO, Steel structure MTO, main cabling

MTO, etc.

Issue or review/approval of documents and drawings needed for civil/ underground construction works (e.g. earth works, foundation drawings, pipe lay-outs, trenches, pavements, buildings, etc.), and above ground mechanical erection (e.g. Steel structures, storage tanks, pipe racks, cable trays, static and rotary/package equipment), etc.

Issue and/or review/approval of Operating/Safety Manual and Pre- com/commissioning procedures and specifications.

Field engineering services normally means the design and engineering related services at site by the detail engineering company specialist staff with the objective of assisting the construction company in doing their scope of work through offering clarifications, trouble shooting, helping them to understand and implement the final AFC (Approved for Construction) engineering documents and drawings, make or approve the necessary adjustments and corrections in the course of construction work, and finally maintain and up-date the field marked-up “as built” documents.

Field Engineering Services are normally a continuation of Basic/Detail engineering services and may also involve licensor /technology owners staff as well.