Aircraft scheduling

Flying to MBJ five weeks today so I was just checking todays delays. Several LGW flights are delayed, yet only one 747 (VS16) appears to be late in. How long does it take to " turn around" a 747. I ask because today's 65 is VGAL which arrived for time from LAS yet 65 is delayed. Is VS running operation so tight that there is no room for the slightest delay with the knock on effect. I ask this because it's seems that over the last few years Everytime I fly with VS there are delays and personally speaking this has been a major factoring why I stopped flying VS a my preferred airline. I was gold for several years and this year will be back to red. I have returned to VS for this flight because I heard things were getting better and I have purchased 8 UC tickets for my family. I hope they dont let us down.