Monday, January 30, 2012

Principles and patterns

I have looked at these "principles" for many years and it seems to me: firstly that they are effectively constraints (almost like goals, measures of success i.e. something to be achieved ideally) and that secondly they are often opposing constraints. So that what is required in design in an understand of the trade-offs. 

This turns out to be very complex if tackled from 1st principles so in mature disciplines the idea of patterns is used which effectively encapsulate a set of principles (and materials) to suggest how something can be achieved. The seminal work on patterns (Pattern Language) reflects a practical approach in another design discipline - which also has principles.

I am not convinced that principles in their raw form can effectively be consumed and applied. They are good things that theorists like to talk about but almost useless in practice.

To use an imperfect analogy - cars one could imagine a set of principles: agility - be flexible for many purposes, go off road; capability - be able to store lots of things and people; user appeal - appeal;  speed - be fast; ease of use - easy to operate, park etc.; good TCO - economical to run; cost effective - economical to buy; etc.

But these won't tell us what type of car we want to buy or build - let alone details of a specific model. What we 1st need to understand is the pattern.  

Do we want an SUV: agility - yes; - capability - yes; user appeal - no; speed - no; ease of use - no; good TCO - no; cost effective - no.

Do we want an small hatch - agility - partial; capability - no; user appeal - no; speed - no; ease of use - yes; good TCO - yes; cost effective - yes.

Do we want an sports car- agility - no; capability - no; user appeal - yes; speed - yes; ease of use - no; good TCO - no; cost effective - no.

Our principles have not changed - but our priorities have and the patterns SUV, Hatch, and Sport car reflect this.

No comments:

Post a Comment