Congress of a thousand medical professionals
If 1,100 participants from 90 countries fly into Prague for a week to attend a medical congress, logistics and the technology prevailing at the congress venue are the strategic bottlenecks: If that goes off smoothly, everything else will, too.
Hand on heart: How often have you sat in a convention hall where the speaker's microphone had a loose connection, or the next video wasn't played because the format wasn't right – Ahem? Did no-one check compatibility ahead of time? Not in the standard organisation, no. It simply cannot cope. What you need are event logisticians who have perfected each procedure right down to the smallest detail by working on projects hands-on umpteen times through the decades.