Engineering Change Proposal

[thien2002]

I am a contractor to the Air Force, Navy to build test cell for jet engines. I am asking if you know an Engineering Change Proposal process which we have never done in the past. How long will it take from Engineering stand point to verify drawing, approve by all staff members, and complete any estimate or engineering issues. Can anyone give me a breakdown of time (engineering)? Air Force is coming for an audit and they want to know the engineering estimate for ECP. Thank you.

 

[IRstuff]

Unfortunately, only you can truly answer that question.

You are asking total strangers to figure out how long your own process is supposed to take.

Your own people should be doing the estimate. If you've been careful, you would have built up some sort of charge number system that you can use as historical data for your estimate. Otherwise, you'll only be able to cite engineering judgement as your basis of estimate.



TTFN

 

[thien2002]

Dear friend,

I said that we have never done any ECP for company before as the statement. I am just asking for general estimate for any person has been through the process, they would understand and share with me their breakdown structure. I would appreciate your help anyway. Thank you.

 

[cappe]

The answer to your question depends heavily upon how complex your drawings are (whether or not you have to check the interfaces between parts, tolerance requirements, interchangability requirements with standard or custom parts, etc., etc.); how extensive the changes to the design are; whether you are working with your own drawings or someone else's; and how you produce drawings (software or hand drafted).

For a very rough order or magnitude estimate you could take some percentage of the time to draw, check, and approve. What that percentage to use is open to considerable interpretation and judgement but, something like 15-25% may be an acceptable answer to your client. Of course, experience is the best basis for estimate.

As for how to accomplish an ECP I suggest you consult ASME Standard Y14.35, Revision of Engineering Drawings and Associated Documents (about $50 from ASME.org). Another very good source of guidance for drawings for the government is the Drawing Requirements Manual by Global Engineering Documents (about $200, over 1,000 pages from global.ihs.com).

 

[Suerte]

If you are looking for a process to do ECPs, there is no real standard. Individual companies have their own processes. As a general rule though, it takes about 50 working days (~2 months) to process an ECP through a large company/program. Again, this really depends on the magnitude of the change. I have seen ECP preparation take 6 months. This time assumes that you have an approved request for change from your customer. If you are a small company with good control of your internal activities, you should be able to produce a good ECP in 2 months. Just make sure that you fully understand the change, and the total impact to your contract.

 

[thien2002]

Dear friend,

Suerte, I asked this question back in July 2003. I am surprise that you reply to this one. However, it's still helpful from your share of experiences. I got laid off from that company a few weeks but now working on a different job. Again, thank you for all of your time.