I'm writing my 5,000 word upgrade report. The first section states that it should be a brief section. How many words would you say is suitable for this brief section, considering the report is 5k?
I did my upgrade recently and my report had to be 12-13k words with a brief introductory section. I think my 'brief' section was around 500-600 words so as your report is shorter I would aim for about half of that so it becomes like an abstract. However this depends on what else you have to have in the report. Mine was 5k lit review followed by methods, results from pilot study and a plan for the thesis as a whole so I could get away with having a longer introduction.
I think around 200-300 would be OK considering you only have 5k words to play with.
I would try to find out how firm the 5k word limit is. For my upgrade report, I went well over the limit and nobody cared. Learn the rules and then push them to just before they break. If the 5k is firm, write the other bits first and then see what you have left to play with (I am assuming you are talking about the Introduction).