Thursday, December 4, 2014

Why software estimates change and inflate

As a software developer (Architect?) I find myself in a constant battle with clients and project managers about changing estimates and their inaccuracy. I've lost count the number number of times I've given an estimate and then had to revise it to the dismay of folks who assumed seemingly subtle changes would move the estimate down or allow it to remain the same, only to see it creep up. There are a number of variables that increase the estimation risk and I'll briefly touch on the major factors.

Major factors are:

  • Changing requirements/assumptions - a fundamental truth is that any change incurs overhead. The act of changing the design to remove a requirement is is work too...remember, even simplifying the design is work. Removing a requirement mandates revalidating a design against (even if they're simplified) the new requirements.
  • Changing the team structure - an experienced dev is much more effective than a newbie. Moreover a person well versed in a particular solution is often more effective than a more experienced resource who is unfamiliar with the existing code. Creating estimates for an unknown team is tremendously difficult and often leads to large inflations to account for the risk of getting an unvetted resource.
  • Work fills to accomodate available time - if you give a developer 40 hours to complete a task, they will almost always take AT LEAST that amount of time. Even if it seems to be a simple task, they will spend extra time to analyze options, test, and otherwise use available time even if they COULD have potentially "just done the work" in four hours.
  • Estimates are just starting points - the harsh reality is that estimates for non-trivial software are starting points and evolve as more information becomes available. The more analysis you do without obtaining more information, the higher the multiplier is that the estimate is based on faulty information (especially when it involves the factors mentioned above

The short version is that "all software development is design". Any change anywhere changes that design and thus creates more work. Agile proponents realize this (maybe implicitly) and combat this problem by locking down design for periods of time to help move things forward (with real deliverables). Long drawn out design cycles cause extra work that too often is underwater.

Tuesday, November 25, 2014

Easily changing java versions in OSX

In OSX, they've frankly done a pretty good job of enabling multiple versions of java at the same time, but just as frankly it's somewhat obscure and inconvenient to manage multiple versions. It's not mind bogglingly difficult but for us oldsters who are lazy, I created a convenient way to switch versions inspired by (though nowhere nearly as awesome as) rvm for ruby.

  1. Download all of the versions of java you want to use from the appropriate location java 1.6, java 7, or java 8. (you need at least one to start with)
  2. Add the following lines to ~/.bash_profile
  3. jvm() {
     export JAVA_HOME=`/usr/libexec/java_home -v "$1"`
     java -version
  4. Either source .bash_profile by typing ". ~/.bash_profile" or simply close your terminal and relaunch

At this point you can change versions of java by typing:

jvm 1.6*
jvm 1.7*

Yes, there's more to it, refer to java_home for more version matching options, and it could be way more awesome, but this should be a quick help for those who just need a simple way to switch when troubleshooting/testing jvm version issues and you want to quickly change JDKs in an automated fashion. Note, this also works with fix pack and minor versions, you just need to refer to the version pattern matching of the '-v' option for java_home to know how to use it.

edit - I originally had an alias pointing to a function until a gracious commenter pointedly asked why I did it that way. Not having an answer I eliminated the alias. This shows the strength of my convictions about the "right way" to do things...

Thursday, September 25, 2014

Why OSX sucks and you should use ubuntu instead

OK, I confess, I use OSX almost exclusively and have for a number of years now. I DO have a number of Ubuntu machines, VMs, and servers in stable, but my goto device is a macbook pro (actually two of them, one for work, one for fun). I love the hardware, but the OS and specifically it's lack of a software package management tool has just a level of suckyness that irritates me.

Now, don't get me wrong, OSX suckyness is nothing compared to windows, but it seems to be frozen in 2004 and is not moving forward at a pace I think is acceptable considering the huge advances Ubuntu has made in a very short time frame. In the same vein, the UI for OSX is awesomely polished and user friendly, but there are some major pain points I can't seem to get past.

My Points

Ubuntu, being a Debian variant has an awesome software package management system. More importantly, just about anything you could ever want is ALREADY THERE in some shape or form. OSX has homebrew and macports...which both suck and are just plain confusing. Why in the world there is a need to do a recompile on a platform as tightly controlled as OSX when Ubuntu can deploy binary packages is a complete mystery to me.

This having been said

Apple is a hardware and user experience company, not a software company. Your hardware awesomely rawks, keep it up. Your software is pretty darn good, but you need partner with canonical and/or an open source company to get a decent package management solution (or just fork Debian...or just partner with canonical). Your development tools are horrific. Please contact a professional developer who also does open source, not a sycophantic Apple Fanboi to help fix the problem.