Skip to main content

Finding and Evaluating Options

Of all the rules, techniques, and heuristics I've tried for making design (and other) decisions, the "Rule of Three" keeps surfacing as one of the simplest and most effective to use.

There are two variations of the Rule of Three. The first, from Secrets of Consulting: A Guide to Giving and Getting Advice Successfully by Jerry Weinberg is about evaluating options:

If you can't think of three things that might go wrong with your plans, then there's something wrong with your thinking.
This sounds rather negative, but if you think for a second, it makes sense, and it's really about being constructive. Design decisions are about evaluating trade-offs. You want to pick the decision that has the problems that you can live with. When we've been struggling with a problem and come up with a plausible option, we tend to want it to work. If you don't think about what might go wrong you're making it harder for a good idea to succeed. The worst that can happen is that you find that your "great" idea doesn't solve a likely problem. This is good. The best is that you discover that your idea addresses issues you didn't consider. This is very good.

Is thinking up three possible problems with a decision foolproof? No. But this approach strikes a good balance between Big Design Up Front and being too impulsive.

Weinberg's original Rule of Three is great when you have an option to evaluate, but how do you develop options? In Behind Closed Doors: Secrets of Great Management (Pragmatic Programmers), Johanna Rothman and Esther Derby describe a related Rule of Three: Always come up with (at least) three alternatives when trying to solve a problem. While 3 can be an aribitrary number, Johanna and Esther explain that:
  • One alternative is a trap.
  • Two alternatives is a dilemma.
  • Three provides a real choice (and gets people in a frame of mind to come up with more).
I've used the combination of these approaches for design decisions with great results. (I describe one case in my first blog post ).

You may not always need three choices when looking at a situation. And when you have a solution in mind, you may not always need to think of three things that can go wrong with it. On the other hand, the cost of following this process is small, and the benefits are great. Make the Rules of Three a habit and you may find yourself making better decisions.

Comments

Popular posts from this blog

Continuous Integration of Python Code with Unit Tests and Maven

My main development language is Java, but I also some work in Python for deployment and related tools. Being a big fan of unit testing I write unit tests in Python using PyUnit. Being a big fan of Maven and Continuous Integration, I really want the  Python unit tests to run as part of the build. I wanted to have a solution that met the following criteria:
Used commonly available pluginsKeep the maven structure of test and src files in the appropriate directories.Have the tests run in the test phase and fail the build when the tests fail.
The simplest approach I came up with to do this was to use the Exec Maven Plugin by adding the following configuration to your (python) project's POM.

<plugin> <groupId>org.codehaus.mojo</groupId> <artifactId>exec-maven-plugin</artifactId> <executions> <execution> <configuration> <executable>python</executable> <workingDirectory>src/test/python</workingDirect…

Displaying Build Numbers in Grails Apps

Being a fan of Continuous Delivery, identifiable builds, and Continuous Integration: I like to deploy web apps with a visible build number, or some other way of identifying the version. For example, having the build number on the login screen for example. In the Maven/Java world, this is straightforward. Or at least I know the idioms. I struggled with this a bit while working on a Grails app,  and wanted to share my solution. There may be other, better, solutions, but the ones I found approaches that didn't quite work they way that I'd hoped.

My requirements were:
To display a build number from my CI tool, where the number was passed in on the command line. In Bamboo, for example you might configure a grails build as
-Dbuild.number=${bamboo.buildNumber} warTo only change build artifacts and not any source files.To not misuse the app version, or change the names of any artifacts.To be simple and idiomatic.I realized that that Grails itself changes the application metadata (appl…

Motivation Visibility, and Unit Testing

I've always been interested in organizational patterns (such as those in Organizational Patterns of Agile Software Development). I've recently found myself thinking a lot about motivation. I'm now reading Drive: The Surprising Truth About What Motivates Us and just finished Rob Austin's book on performance measurement. Being the parent of a three year old, I'm finding more and more that "because I said so, and I'm right" isn't too effective at home. My interests in motivation are closely related to my interest in writing software effectively. Writing software is partially a technical problem about frameworks, coding, and the like, but the harder (and perhaps more interesting) problem is how to get a group of people working together towards a common goal. Agile practices, both technical and organizational, build a framework which makes having the right amount of collaboration and feedback possible. But there's a bootstrapping process: How do yo…