Word count: Given that the report is in Powerpoint format plus notes underneath, an essay type format is not required.  But there should be enough detail on the powerpoint slides and notes to the equivalent of 1500 to 2000 words but it is not essential.

What is more important is how you convey the investigation in Powerpoint format and what specific points of Reflection you provide. So its the formal routines/tools/techniques under consideration, why you did the things you did, how you would sell  the improvements considered and discuss their implications.