"The calculation of risk is probability times impact". This is not just a random quote (to me...) It is the basis of risk management that I used a lot in my daily job as a maintenance engineer.
Now I still use it when I develop my websites, in example for our local community news website Zeijen.nu. The website is really *huge* and has a very large and loyal visitors group. People count on the information at the site for the local news, for planning activities, etc. We can't have it when the site goes down due to technical errors... So as the lead developer I make design choices based on the risk management principle when implementing all kinds of functionality using UDT's, plugin tags and modules.
Each addition to the website increases the probability of breaking down the site. So I always ask myself, what impact does it have on the website's objectives when this feature fails or breaks (a part of) the site. Do we really need this within the website's CMS, or can we use external systems? And if we do need it within the CMS, what kind of technology has the smallest breakdown probability... Do we need a full blown module or is there a simple alternative with the same functionality?
A lot of things I describe here at my blog are the result of these on risk management based design choices.
But also the development of own module and tags:
Well, let's be honest a local news website going off-line isn't the end of the world. But I can imagine for a company/web shop it is a different story, it loses sales. Anyway I take my task here serious and try to do the job as good as possible: quality insurance! So I hope my experience described here can convince you to also take risk management in consideration when making your "design choices" and improve the quality of your website.