Most management theory is to be mistrusted. Not because it is wrong, but because too often it is impractical. There is no point in absorbing and trying to apply the heights of academic excellence at one end of the company, if extremely basic and essential management principles are being flouted everywhere else.
This book is about one basic principle which is often neglected. The concept is simple. It is to learn from the mistakes of others. It has several advantages over learning from one's own, but it requires the discipline to identify faults and recognize that one might be duplicating them. Mistakes are opportunities for improvement, and avoiding gratuitous mistakes is more important than gilding the lily on the things you do well. Ideally you can achieve both.
Mistakes can fall crudely fall into five categories:
1. Errors of omission (failure to act or communicate)
2. Errors of commission (doing things you ought not to have done)
3. Qualitative errors (doing the right thing inadequately or by the wrong method)
4. Errors of timing (doing the right thing too early or too late)
5. Credibility errors (doing the right thing, at the right time, but in such a way as to irritate everyone or discredit the action)
Every one of these can teach us a lesson. All about you, at all levels of contact, people are continually reminding you of the human failings which make good people bad managers. The task is to turn those failings into future virtue. There's a refresher course waiting for you at the office every day.