In my several decades of experience in all phases of project implementation, concept definition, FEED, detailed design, procurement, construction, testing, and commissioning, I always find that some Engineers despite having a very good design "ON PAPER" are not practicable on-site, either on issues of constructibility, maintainability or worst safety.
In every project, whether green field or brown field, familiarization of actual site condition is necessary.
Below are some actual scenarios which illustrate Engineers missed to consider essential site parameters
Whichever infrastructure was constructed first, the electric tower or the road, someone missed considering the presence of another infrastructure in the location. The contractor is also stupid enough to proceed with the construction despite site restrictions.
The above figure is just illustrative. However, this is a reality that is faced by the contractor during construction.
This is the most taken-for-granted parameter during design. It may be safe, and constructible but is it maintainable? A classic example of this is equipment access to replace or maintain as it is blocked by other structures or equipment. To replace, it may require removing other equipment to gain access to the equipment under maintenance.
Another issue of maintainability is equipment spare parts availability. Before the end of life of the equipment, it may be considered obsolete and spare parts may not be available in the market anymore.
The manufacturer of this electronic card for a VSD has closed business. Spare parts have been taken off the market. The owner of the VSD needs to resort to electronic card component replacement to sustain its manufacturing process. It is not always a success though that despite the replacement of defective components, the electronic card still does not work as expected.
A study has been considered to replace the VSD with state-of-the-art equipment, but the cost is so restrictive that it is not feasible due to stiff business competition with imported products from China.
A well-experienced design engineer will be able to integrate all factors particularly site conditions into the project to ensure safety, constructability, and maintainability.