Well, for the past couple hours I've been otherwise occupied with my other project, besides this one but I've still been thinking about this discussion of design and implementation. I'm working in my basement installing vapor barrier, framing, insulation and wallboard prior to building permanently attached storage.
I'm sure the architectural drawing (the design phase) of my home assumes a smooth level cement floor, 90 degree angles in the corners, and straight 90 degree perpendicular cement walls. In reality (the implementation phase), NONE of these are true. In addition, there are little nubs of cement sticking out from the walls where the forms had developed holes and there is a small ridge along the floor surface where the forms did not exactly meet the floor. Further, the distance from the floor surface to the beams is not consistent since the cement is not perfectly smooth. Thus the storage unit cannot be scaled perfectly but must be custom measured and cut to fit. My task is to now implement a new phase of maintenance of these 'features' by adapting my design of the framing, wall installation, and storage construction.
Our design and creation of database systems is very similar in that while we can't always assume a perfect design by the architect and a perfectly straight result by the builder, we hope that the architect did an acceptable workable design, and that the builder adapted where necessary without jeopardizing the integrity of the design and the adaptability to future needs by making good choices.
One of the best days of my IT career was they day I told my boss if the problem was so simple he should go fix it himself.