The organization of the report is the most important factor in attempting to satisfy all of the diverse purposes and audiences. The outline below is typical for an industrial report.
The Executive Summary should be less than one page. This page may be the only page that higher levels of management reads, so it should be a very condensed version of sections 4,5, and 6. Include only items that are of most interest to the upper management. Other items may be more important to your technical audiences who will read on.
The authorizing manager will probably rely on input from his/her direct reports before making a decision on action. Those managers will read further into the report, with the material in sections 4-6 being the most important. Thus, those sections are placed at the beginning of the report, not at the end.
The rest of the report is mainly aimed at the other audiences mentioned in the previous post...team members, peers, self, interested colleagues. Some people prefer to put everything after section 6 in the appendices. I opt for the outline above because the reader has the option to stop reading further at any point. Your supervisor or company may have a different preferred report outline, which you will, of course, use.
With today's word processing capabilities, I place important plots and tables of results directly in section 8, Discussion of Results. The alternative is the old style with plots, figures and tables placed in the appendices. Placing these items in section 8 saves the reader time and aids the reader in understanding the plot, etc. because the description is adjacent to the plot.
The above outline was designed to aid the various readers. In the next post, I will discuss how this outline also aids you in writing the report.