It is almost confusing for the students as well as academic writers to distinguish among letter of transmittal, executive summary and introduction while writing any report. I am going to discuss some clear cut difference among the three terms.
First of all it should be made very clear that letter of transmittal and executive summary have nothing to do with actual topic you are going to write about. Only Introduction part deals with actual topic of report.
The purpose of executive summary is to tell the reader of the report what is your report is about. What sections deal with what aspect of report. For example you your report deals with assessment of network security it is good to write “this particular section deals with weaknesses in the network security, that section deals with recommendations.” In a nutshell, it is narrating the story in very limited words.
Now comes the Letter of Transmittal. Letter of transmittal is actually written from the perspective of person who was delegated the task of report writing as per case scenario to the authority or person who gave the report writing work according to case scenario. Here, case scenario means the case study. If in the case study, you are assigned role of security analyst and you have been delegated the task of assessing security position from Board of Directors, your letter of transmittal typically should be written as follows (just an example):
Letter of Transmittal
The Board of Directors
Subject: Assessment of network security
The attached report presents and discusses the current state of network security position of our company ABC. In this report I have outlined the limitations of existing tools and techniques as well as recommended tools and methods to be used. I hope you will find the report useful for further action.
Mr A (Network Analyst)