I have been quite behind in my magazine reading, and this morning I caught up to August (2008 - at some points, it has been necessary to specify the year when saying how far behind I am).

There is an interesting article in Dr. Dobbs, by Scott Ambler, regarding methods of estimating costs of software development, and whether the typical, fixed price model is even ethical.

"fixed price refers to a project where the cost, schedule and scope are set early in the lifecycle."

His examples include very large numbers (at least compared to my current projects), which I found distracting, but the percentages are useful.  I liked this quote, which is the reason for this post:

Traditionally, we've wanted to believe in the concept that "software engineering" is 80 percent science and 20 percent art, but in practice development has proven to closer to 20 percent science and 80 percent art.  Or perhaps the 20 percent of software engineering that is art is simply 16 times harder than the 80 percent that is science.

I have a meeting in two weeks where I'll meet a potential customer for the first time, and they'll likely expect a fixed-price quote, though they did say they have enough money for the project, so hopefully, it won't be too hard to figure out what the project should cost.  I just saw another quote from a related article on the online version of th e magazine, where the author quoted someone else saying that customers expect vendors to provide a "five 9's" estimate on "one 9" of requirements. I think that's pretty accurate.

Posted by Jon Daley on November 14, 2008, 9:46 am | Read 6464 times
Category Programming: [first] [previous] [next] [newest] Reviews: [first] [previous] [next] [newest]

So, a software post that I understand much of is a rare thing, so I'll venture to ask, what's "five 9's"?

Posted by IrishOboe on November 15, 2008, 3:05 pm

A measure of reliability: 99.999% which translates to ~3 seconds a month when you talk to a webhosting person. Lots of web providers offer a guarantee of 99.9% uptime, which means they allow for 45 minutes of downtime every month, and basically, aren't guaranteeing anything, since you can generally do three 9s using your home broadband connection.

So, the phrase is being used out of context in the above quote, but you probably get the idea.

And one of my quotes from my e-mail signatures: After the Gore/Bush narrow margin counting, etc. a supreme court justice remarked, "Hey, this is the government. You just can't expect five 9s".

Posted by jondaley on November 15, 2008, 3:12 pm

So, Stephan is more rigorous than I am, and researched that quote, to find its source was Jack Ganssle, an embedded engineer whose newsletter I read, and who usually has a joke at the end of the newsletter. I have my doubts as to whether I saw originally saw it in that exact context, or if it was quoted somewhere else separately, unless I understood at the time that it was a joke, and have forgotten since.

As I said to Stephan - Supreme Court justices say all sorts of things you wouldn't expect them to during a hearing, so I (still) don't find it all unlikely that one of them actually did, or could, say something like that.

I came across this FCC indecency transcript the other day.

Posted by jondaley on November 16, 2008, 9:45 am

The quote came up today on an outgoing email, so I went to change the attribution, and then went to search online to see where else it was found. I saw the Ganssle article, and the only other source is Rick who also has a random generator, and someone I know from Providence Church, and probably thought it was pretty good, so copied it from me...

Posted by jondaley on December 5, 2008, 11:18 am
Add Comment
Add comment
E-mail me when comments occur on this article