In Search of Excellence has been credited to have started the so-called management guru business. Written in 1982 it is the first book that aims to explain company success in a popularized way. Subsequent books on the subject are, for instance, Competitive Advantage (Porter, 1985) and, more recently, Good to Great (Collins, 2001). I gave the book three stars, but in that assessment I have tried to consider that the book is old and business knowledge has evolved ever since - yet the book is a seminal piece of work. If the book would have been written more recently, it probably would have given one or two stars to it.
Based on a major McKinsey study, In Search of Excellence identifies eight characteristics common for excellent companies: (1) a bias for action, (2) close to the customer, (3) autonomy and entrepreneurship, (4) productivity through people, (5) hands-on, value-driven, (6) stick to the knitting, (7) simple form, lean staff, and (8) simultaneous loose-tight properties. Personally, I don't find this set of characteristics very surprising or insightful - it would be difficult to imagine a financially excellently performing company that doesn't get things done, doesn't care about customers, is excessively bureaucratic and so forth. Moreover, some of these characteristics are at most directionally true such as "stick to the knitting" (consider e.g. GE - which btw. was part of the book's sample).
Nevertheless, In Search of Excellence provides interesting examples and a lot of good practical advice. I have to admit, though, that for me many of the examples were tedious reading as they represented often quite outdated issues. What I liked most in the book was the theory. Peters and Waterman have succeeded in picking up theory that mostly has stand the test of time. I would assume that for instance Henry Mintzberg and Karl Weick were much less known in 1982 as they are today. James March, Alfred Chandler and many others still are considered great management thinkers. My fancying for the theory is partly explained by that I in general agree with the author's that it is more often the soft issues that are important, not the hard issues.
The methodology used in the study is not particularly robust. An original convenience sample of 62 companies is analyzed on six different measures of financial excellence such as average return on equity between 1961 and 1980. In order to be "excellent", a company must be in the top half within its industry in four of the six measures. 43 companies met this criterion and the authors conducted interviews in them. Underperforming companies were not really included so the study doesn't tell are the identified characteristics unique to excellent companies (although the authors make a vague statement that underperforming companies were also analyzed, but they didn't focus on them). Also, for unclear reasons, companies that were perceived excellent but were not part of the initial sample, were included in the book's example, which is a little confusing (are those companies also excellent, and if yes, on what basis?).
Finally, a point I find very intriguing, is that in an article for FastCompany in 2001 (http://www.fastcompany.com/magazine/53/peters.html), Peters admitted that he and Waterman faked the data. This raises some interesting ethical questions: why does the new foreword of In Search of Excellence (written in 2003) not raise the issue? Why does McKinsey still embrace the book on its web page without mentioning that the data has been cooked? To me it seems to imply that an aspiration for truth is easily put aside in order to serve self-interested purposes.
So what is the "so what" of In Search of Excellence? Considering that the methodology is as weak as it is, it's hard to draw any far-fetched conclusions from the study. Neither does the book try to do that - it rather states that excellent companies seems to have these characteristics in common, and if you focus on them, maybe also your company will be excellent. Now considering that the data was cooked, the book doesn't really say even that, but rather provides a seemingly good narrative and dwells on some interesting ideas, while at the same time being short on intellectual rigor and ethics.