Why is FEED done? 3

[sfmech]

Consider this imaginary situation created. Client wants to set up a process plant. Process licensor has provided the technology and made a Basic Engineering Design Package (BEDP). Using this package client has placed an EPC (Engg., Procurement & Construction) order on XYZ company. EPC contractor is supposed to carry out FEED, and then Detailed Design. Why is FEED needed to be carried out? What purpose does it serve?

 

[ZDR1985]

Why is FEED needed to be carried out? What purpose does it serve?

For design optimization.

 

[zdas04]

Nonsense. When the concept was first proposed in the late 1980's, some PhD candidates had reviewed several major projects that had had significant cost and time overruns. Their conclusion was that the root cause was: (1) Detailed engineering not completed before construction began; and (2) Detailed engineering caused significant changes to already completed portions of the plant. Hence we need to do "Front End Engineering Design (FEED)". This conclusion sounded eminently sensible to industry and it was adopted as whole cloth.

FEED was intended to be the detailed design, but it was found that too much detail before the start of construction caused too many change orders when it was found that things didn't quite fit where the FEED team required. The evolution was to "finish" the process design, "finish" the mechanical design for major components, and develop preliminary Civil, Minor Mechanical, and Electrical design. The preliminary designs were intended to be completed early in the construction phase.

That intention has evolved to the FEED being very detailed in all areas. Also Detailed Design often ignores the work from the FEED and starts over with a blank page (since the FEED contractor often gets fired for cost overruns and delayed delivery of the FEED and the Detailed Design is done by a competitor who can always find fault with the FEED). It is a really broken paradigm that is a major contributor to the ills that I discuss in my paper on ENGINEERING.com.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist

 

[bimr]

The FEED is intended to further develop design, including detailed specifications and layout to get a more accurate cost estimate as a deliverable to the EPC bidding stage. The FEED identifies equipment and provides detail design of the project. The FEED contractor prepares engineering documents and bid packages to a sufficient level of detail to be used in the EPC bidding.

 

[EmmanuelTop]

I found that both David and the others are correct - and this really varies from one case to another.

For smaller greenfield projects involving open-art technologies, performing FEED is usually a redundant activity that will consume your time and money and essentially bring no added value. If a proper prefeasibility study has been performed, one can step directly into EPCC or EPCM project. For these types of projects, one will realize that not many changes (and certainly no major changes) will occur during detailed design (as compared to the design that would have been completed in FEED).

On the other hand, complex and especially brownfield projects do require front-end engineering, in my opinion. There are so many hidden obstacles (plot space, utilities, safety studies, construction issues etc.) that would escalate the cost of your project by at least 50% if these items are not identified and addressed during FEED. I know this from experience - it is simply impossible to get into the required level of details in a typical prefeasibility study, and many of them will show up and bite your bottom when you do not expect, during EPC project phase.

David is correct in the sense that performing FEED has become mandatory for ALL projects, regardless of what type and what size and what environment is your project in. And like any blind-followed rule which was originally adopted for a specific case, this will come with a trade-off and get you spending more money and time than you really should. But in the end, everybody learns this simple truth in his own way.

Dejan IVANOVIC
Process Engineer, MSChE

 

[bimr]

http://en.wikipedia.org/wiki/Front-end_engineering

 

[georgeverghese]

Two outcomes expected from FEED:

a)Develop the design further to provide sufficient definition for Detailed Design , and also optimise the design where possible

b) At the end of FEED, enable the preparation of a project cost (to a predefined level of accuracy) and schedule that will be used by the Operator / JV owners to approve funding.

 

[EmmanuelTop]

It seems that many people out there have bad experience with FEED

Dejan IVANOVIC
Process Engineer, MSChE

 

[BigInch]

Big problems with FEEDs. Perpetuates the unknown. Kick the can down the road.

If actual project bidding and purchasing activities are delayed until Detailed Design, selections between what can be some very important alternative raised during PRE / FEED phases that reduce to simple choice based on OPEX / CAPEX cannot be made, as the typically wide variations in budget estimate margins prohibit sufficient resolution to differentiate amongst the alternatives. This can result in far too much design definition being being kicked down the road into Detailed Design, leaving one wondering what the purpose of FEED was at all. It really just turns out to be an exercise for the MBAs to bracket budgets, with only slight value added to actual engineering, other than narrowing down from amongst the very few concepts that have the widest and coarsest resolution. Just not a lot of bang for the buck results from FEED. Not one decision resulted that I could not have not have reached beforehand. Many of the more innovative options that might have been valuable to investigate, ignored, apparently to arrive at an easy answer in the short time allowed to complete the feed study. Many hours burned arriving at obvious results, in fact even narrowing down the options to a resolution far superior than the cost estimate's margin of error. We know that after 2 pre-FEEDS, including something like 1000 hours of flow assurance work, that we should build 1 of 4 options. They just can't tell you which power source or pump drivers you should use, what your pipe diameter is, 24", or 26", or how large your plot plan should be.

 

[BigInch]

The real problem is that engineers think it's an engineering exercise. It is not. These days it's just another FID document. NAFC - NOT Approved for Construction

 

[sfmech]

How will you judge whether the FEED package is good enough for Detailed Engineering? What I mean is how will you judge that the FEED package is neither under developed or over developed. In my opinion, an under developed package will bring out various change orders. An over developed FEED might restrict the leeway of EPC contractor.

 

[EmmanuelTop]

It depends on what does one expect from FEED, and what is the project in question.

I remember having a few projects where it was virtually impossible to step into EPC (I don't think anybody will go for separate Detailed Design and PCC phases with different contractors, for many reasons) immediately after the Selection or Pre-Feasibility phase. They were all revamp, brownfield projects. Even if you get all the main equipment selected and sized to the tiniest details during pre-feasibility stage, it is very hard to imagine how will all this fit into a predefined plot space, predefined utilities, safety constraints, shutdown frame of the existing facilities, etc. etc. This was the moment for performing FEED engineering - taking care of the layouts, constructability, SIMOPS, expansion of Utilities, safety studies. Sometimes, you could see how a perfect concept for a greenfield environment simply doesn't work for a brownfield project. I don't see how all this important stuff can be performed during pre-feasibility stage. If someone finds out and develops complete methodology, I will propose this person for Nobel prize.

For greenfield projects (vast majority of them), added value of FEED is almost always insignificant. If you have done the project economics well, price variations arising from inaccuracies in equipment and materials calculations in pre-feasibility phase can be pretty much well covered by the contingency. The conclusion based on 13 years in this business is that requirements for FEED should be assessed on a case to case basis. Performing FEED for every project, or not performing FEED for any project - I have found out that this strict rule simply does not work for me. I think you and Dave are saying something very similar to that.

Dejan IVANOVIC
Process Engineer, MSChE

 

[EmmanuelTop]

Also, many of the urbanism permits require FEED-level of details for the related engineering documents. This varies from country to country. You don't want to sign the EPC contract and then find out that no construction authorization will be granted.

Dejan IVANOVIC
Process Engineer, MSChE