One of the most important aspects of working on a project is to present the work done in a proper report. A report is written to convey some ideas to the others. The others could be a plant manager, who is not an engineer, or be your superiors of the same profession, or be some technicians. You must keep in mind that, no matter how good your work is it will be a worthless junk if you cannot transmit it to the reader.
A report should be clearly and intelligibly written, and should not need your presence by the report for further explanation to the reader about your considerations during the preparation of this report. You must therefore be able to express yourself to the readers by clearly stating your goals, your approach, your work and your interpretation of the results.