As I said in the last post, you can use passive voice:
1) When you don't know who did the action. Look at this sentence for instance: "Those who committed the crimes will be punished." We don't know who did the action.
2) When your readers don't care who did the action. Look at this sentence for instance, "Passive voice may be used in a number of different situations." I used passive voice in that sentence because you don't care who did the action.
3) When you don't want the readers to know who did the action. Examine this sentence for instance, "The CEO was said to be resigning." We certainly don't want the readers to know who stated that rumor, especially if we started the rumor!
4) When the receiver of the action is more important than the doer. Look at this sentence for instance, "While attending a play, Abraham Lincoln was shot by John Wilkes Booth." The world was much more interested in old Abe than it was in John Wilkes Booth, the man who shot him.
5) When you wish to be less confrontational. Look at this sentence for instance, "The report was not submitted on time." You will agree that it hurts less to be told that the report was not submitted on time than it does to be told, "You did not submit the report on time."
One other use of passive voice deserves a brief mention. It is called the "objective passive" and scientists and students of science hold fast to it. They are told they must use passive voice to be "objective." Instead of saying, "We performed a study of blood and its clotting factors," they are more likely to say, "A study of the clotting factors of blood was conducted...." But, as Joseph Williams, a noted writing teacher from the University of Chicago has said, when scientists use the objective passive, they do not prove that the science was subjective, they only make the sentences reporting the science objective.
So, use the passive voice on these select few occasions, but prefer the active voice otherwise. Again, many people use passive voice because they do not want to accept responsibility. If you check Amazon, you will find an interesting book titled, "Mistakes were made." In that book you will see reports of sinners who refuse to accept the responsibility for their sins. They include Henry Kissinger, Secretary of State in the Nixon White House, who says something to the effect that in the Nixon administration some mistakes may have been made - sure, some mistakes were made, like Watergate, Viet Nam, Cambodia.
Use the passive carefully in your writing, but, in business, prefer active voice. Active voice will help you make yourself as clear and direct as possible. Give praise and criticism where due. The criticism may hurt, but only for a little while!