It is a fact that aircraft are designed by a number of skilled individuals who have never even seen it. Once that aircraft is built and has seen service the knowledge database grows rapidly.
Anyone who holds the privelige of issuing an EOI has access to information that will assist him to assess the scenario and develop a strategic plan of action. Knowing the strong and weak points of an aircraft isn't difficult for the average LAE it is getting to grips with how different manufacturer's deal with problems (the SRM). The issuer of an EOI is tasked with staying in touch with all developments that happen during the life of an aircraft/engine, in addition s/he must demonstrate the ability to grow with the technology. It's a pity that these roles often involve promotion out of the ramp work area with the unfortunate side effect that these engineers lose their credability. I have grown up with many of my fellow apprentices who have aspired to these jobs and I can appreciate what they have to do. They are basically the same as us LAE's but they've got a better phone book of people they can call on for help. An EOI is an evaluation of circumstances with a view to getting the best commercial return on a product your employer has bought ot leased
and it allows flight to procede under certain conditions. Were the EOI not issued with signatories as mentioned above,we woul have aircraft sitting on the ground AOG for a widget that is within the strict tolerance laid down by the designer who has never even seen it in the flesh.