Point of View
The first view point you must take is that of the Managers; the people who hired you. What do they think the problem is? What do they want you to do? How free or unfree a hand do you have?
What changes are possible, what is impossible.
For example, a section of the business may be a money loser; yet, the sentimentality of the owner will not let you close it.
Another section could do better; if… but IF the owners are not willing to invest, there is no sense in writing a ten page brief on why and what and how.
As mentioned before; if there is a relationship between a manager and a worker, and it is that manager who hired you, skip.
If not, test the knowledge of the person who hired you. If s/he knows, skip.
If s/he doesn’t, then learn if you have a free hand.
Focus on what you can do, not what you can’t.
No matter how annoyed you may be that the business would do so much better if … and no one is interested in your IF, move on.
Sure, in your report, touch on a few points, but just touch. For if you rile those who hired you, they may not only never call you again, they may convince others not to call you.