@gparasEA suggests that EA Principles Have Little Value. I agree with his title, but his actual text appears to argue that EA Principles have significant potential value and should be taken more seriously.
My view is that EA principles are hugely overrated. In my post What's Wrong With Principles I observed that principles are usually ill-conceived and generally fail to provide a sound basis for collective decision-making and governance. But instead of trying to fix this by producing better sets of principles and enforcing them better, I think we should simply abandon the fantasy that difficult EA judgements can be driven by any simplistic set of top-down abstract principles.
If we are to regard principles as more important than casual suggestions and slogans, then there are some critical requirements they must satisfy. For one thing, credible principles should be based on concrete evidence that they actually work (true and/or useful), rather than the kind of vague wishful thinking and motherhood statements that we find in countless EA documents and presentations. I have seen very little serious attempt to satisfy these requirements, and the belief that things would be okay if only we had better principles sounds to me like wishful thinking.
In a Linked-In discussion (Considerate EA), Ron Segal agreed that principles to underpin strategy cannot just be wishful thinking, and provided a couple of concrete examples. He suggested that the principle 'achieving long term loyalty' entails excluding the kind of campaigns and services that attract short term customer loyalty. So the application of the principle calls for some empirical knowledge about the kinds of thing that are conducive of long-term loyalty, and some understanding of the relationship between long-term loyalty and short-term loyalty. My guess is that this relationship is not straightforward - some kinds of short-term loyalty may evolve into longer-term loyalty - in which case we can only really understand this relationship properly by observing and analyzing the behaviour of customers over an extended period. What I object to is the notion that this kind of principle can be applied as an exercise in pure reasoning, without reference to empirical knowledge.
As for Ron's principle of 'reducing the effort of compliance' - this presumably has to be interpreted as 'other things being equal'. Thus you probably wouldn't want to reduce the effort of compliance if this had the effect of doubling the downstream costs of legal action and compensation. Again, such a principle can only be meaningfully applied in the context of an empirically verifiable (or refutable) model/theory about the interdependencies between different classes of cost/effort.
But here's the thing. If our architectural reasoning is based on principles, and the principles are derived from practical and empirical knowledge, then architectural reasoning must ultimately be justified in terms of this detailed knowledge rather than abstract principles. A simplified and abstract set of principles may provide a useful summary and reminder, but we should not make a fetish of these principles. And if the principles are not supported by practical and empirical knowledge, why should anyone take them seriously?
See reply by Joe McKendrick, Viewpoint: 'enterprise architecture principles hugely overrated' (ZDNet, July 2010)
Related post The Power of Principles (Not) (January 2011). Includes extended discussion with Nick Gall in the comments.