Software Design

What do you think? Are there fundamental lessons here that software designers and companies should be heeding? Are there some products or manufacturers that got this *right*, who have not experienced difficulties with the great 2007 DST transition? If so, what can we learn from their example?

When I read the article Daniel referred to in his Apgar score post, and I came away with a different lesson. My central observation was that simply by tracking the Apgar score, doctors and hospitals became more interested in reviving babies that they might previously have diagnosed as stillborn.

Business problems solved by software systems are inherently multidimensional with dozens or sometimes hundreds of dimensions and complex relationships among them. To name just a few basic dimensions: time, number of users, frequency of use, number of transactions processed per hour, transaction size...

Ronald Reagan used to tell the story of the little boy who thought he was going to get a pony for Christmas. Christmas morning came, however, and there was no pony in his yard...only a pile of horse manure. His Mom found him shoveling furiously at the pile of horseshit, and asked him what he was doing. He said, "Mom, there's a pony in here somewhere!" The "pony" in this article is a tech suggestion. It's at the end of a broader social analysis of why caching can be harmful.

I sometimes write articles connected to my position as a consultant at Northridge Systems that are published in a local Atlanta technology magazine called TechLINKS. The latest article is called "It’s 2:00am. Do You Know Where Your Unattended Systems Are?" I'm going to re-publish this article on the developer.* web site at some point in the future, but I thought I'd point to it in meantime at TechLINKS for anyone who'd like to check it out.

A friend (and former boss) has put together a list of books and links that he finds useful. There is some good stuff, thought I'd share it here.

http://cazano7.spaces.live.com/

I've also been witness to the birth of vast numbers of RUP artifacts into a corporate project atmosphere of total apathy. Sheaves of use-case diagrams, sequence diagrams, UML versions of the Last Supper--you name it; unread, unused, sent straight to dead-document heaven.

I noticed an interesting question on the UML forum which I think a lot of people are struggling with, therefore I took the effort to put it on my blog. The problem was the following: You have a set of use cases and a large set of roles. The stakeholders are not only interested in the use cases as such, but they also want to see which role has which responsibility. In other words: Who can do what?

"You may leave your message after the tone. When you are finished, you may hang up, or press pound for more options. To leave a callback number, press six. To page this person, press star star."

Recently, I was working on the design of a new software system. As the lone designer and programmer, I had the requirements in my head, and had made lists on my white board of some constraints and pitfalls that I knew I had to design around. But I was having trouble. The design was not coming together. How did I get out of it?

What is it about daylight savings time? DST not only makes it hard to get up on that first, dark Monday morning (it was for me today, that's for sure), but it appears to be a bug-fest for software systems. I may be reading too much into things, but I observed what I believe to be Daylight Savings bugs in the software systems of two different vendors yesterday/today, and, while I don't have any statistical analysis to go with it, our support phones have been ringing off the hook all day.

I'm going to try to express an idea here that struck me this morning when I heard on NPR that Johann Sebastian Bach was born on this date in 1685...

Many people don't worry about metadata; rather they are only interested in their data. However, metadata is extremely important as it describes the semantics of 'what' the data represents. In this article, I'll briefly try to convince you of the importance of metadata. After that, I'll discuss some metadata approaches.

After six years of experience in programming in an Object Oriented language, I've identified five different types of classes that occur in OO programming. Knowing and understanding the distinction and knowing how to build each of these types of classes is, I think, essential to writing decent code that is easy to read, understand, debug, and maintain.

Although the title might allude to a phrase in the newest Star Wars movie, the context of this article is more serious. First of all, it is good that people read books. However, they need to be interpreted correctly. How often aren’t design patterns misused for the fun of it? This blog article is about another aspect which made its revival with test driven design (TDD) and extreme programming (XP). This article will focus on the ‘danger’ that lies in the unmanaged use of assertions.