Tag Archives: Christopher Alexander

Why Process Matters

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I’ve been working on a talk for Smalltalks 2014 about Discovering Alexander’s Properties in Your Code and Life.

I don’t want it to be an esoteric review of Alexander’s properties.

That won’t satisfy my audience or me.

I want to impart information about how Alexander’s physical properties might translate to properties of our software code as well as illustrate poignant personal examples in the physical world.

But equally important, I want impress upon my audience that process is vital to making lively things (software and physical things). In his, The Process of Creating Life: Nature of Order, Book 2, Alexander states,

“Processes play a more fundamental role in determining the life or death of the building than does the ‘design’.”

Traditionally, building architects hand off their designs as a set of formal drawings for others others to build. Does this remind you of waterfall software development? There isn’t anything inherently wrong with constructing formal architectural drawings…but they never end up reflecting accurately what was built. Due to errors in design, situational decisions based on new discoveries made as things are built, better construction techniques, changing requirements, limitations in tools or materials, a building is never exactly constructed as an architect draws it up.

Builders know that. Good ones exercise their judgment as they make on the spot tactical re-design decisions. Architects who are deeply involved in the building process know that.

Alexander is rather unhappy with how buildings are typically created and suggests that any “living” process (whether it be for building design or software or any other complex process) incorporate the following ten characteristics.

He challenges us software makers to do better, too:

“The way forward in the next decades, towards programs with highly adapted human performance, will be through programs which are generated through unfolding, in some fashion comparable to what I have described for buildings.”

As software designers and implementers we know that nothing is ever built exactly as initially conceived. Not even close. Over the past decade or so we have made significant strides our processes and our tools that enable us to be more effective at adaptively and incrementally building software. My thoughts on some ways we have tackled these characteristics are interspersed in italics, below.

Characteristics of Living Processes

1.Step-by-step adaptive. Small increments with opportunity for feedback and correction.
Incremental delivery, retrospectives, stakeholder reviews
Repetitive incremental design cycles:
Design a little– implement–refactor rework refine–design…
Design/test cycles: Write specifications of behavior, write some code that correctly works according to the specification, test and adapt…
Tests and production code equally valued

2. Whatever the greater whole is always the main focus of attention and the driving force.
Working deployable software, minimally-marketable features

3. The entire process is governed and guided by the formation of living centers (that help each other)
Code with defined boundaries, separate responsibilities, and planned for interconnections

4. Steps take place in a specific sequence to control the unfolding.
We have a rhythm to our work. Whether it is test-first or test-frequent development, conversations with customers to define behavioral “specifications”, or other specific actions. In order to control unfolding we need to understand what we need to build, build it, then refine as we go. And we have tools that let us manage and incrementally build and record our changes.

5. Parts created must become locally unique.
Build the next thing so it fits with and expands the wholeness of what we are building. Consider our options. Refactor and rework our design. Make functions/classes/code cohesive. Bust up things that are too big into smaller elements. Revise.

6. The formation of generic centers is guided by patterns.
We have in mind a high-level software architecture that guides our design and implementation.

7. Congruent with feeling and governed by feeling.
Instead of just making a test pass, see if what you just wrote feels right (or if it feels like an ugly hack). Reflect on how and what we are building. Don’t be merely satisfied with making your code work. How do you feel about what you’ve just built? How do those using your software react to it? How do those who have to maintain and live with your code feel about it?

8. For buildings, the formation of structure is guided by the emergence of an aperiodic grid, which brings coherent geometric order
Software is structured, too…we’ve got to be aware of how we are structuring our code.

9.Oriented by a form language that provides concrete methods of implemented adapted structure through simple combinatory rules
We use accepted “schemas” to create coherent software systems. We have software architecture styles, framework support, and even pattern languages emerging…

10. Oriented by the simplicity transformation, and is pruned steadily
We can consistently refactor and rework our code with the goal of simplifying in order to enable building more functionality. We rebuild to create sustainable software structures. Even if we come back to some old working code and see how to simplify it, we can rework it taking into consideration what we’ve learned in the meantime.

Yet, let’s not be complacent. Agile or Lean or Clean Code or Scrum practices don’t address every process characteristic Alexander mentions. I am not sure that all these characteristics are important for building lively software. Alexander is not a builder of software systems, although he spent a lot of time talking with some pioneers and leaders of the software patterns movement.

Some process ideas of Alexander sound expensive and time consuming. Do we always need to reflect on how we feel about what we code? Sometimes we need to build quickly, not painstakingly. We need to prove its worth, and then refine our software. Our main thought may be on just simply making it work, not how it makes us or others feel. So how do we add liveliness to this quickly fashioned software? What’s a good process for that? Mike Feathers wrote about Working Effectively With Legacy Code, but there is a lot more to consider. Maybe that quickly fashioned software has tests, maybe it doesn’t, maybe some parts have a reasonable structure, and maybe other parts should be tossed.

We often build disposable and hopefully short-lived software. Problems crop up when that code gets rudely hacked to extend its capabilities and live past its expiration date.

There are most likely different processes for creating lively software, based on where you start, where you think you are headed, and how lively it needs to be (not everything needs to be fashioned with such care).

People are continually building new and better tools and libraries. There is a rich and growing ecosystem of innovative open source software. Process matters. I think we have a lot still to learn about building lively software. It is a heady time to be building complex software systems.

Sustainable Design

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In my most recent IEEE Column, Creating Sustainable Designs, I explore what it means to create software that can be maintained without too many growing pains. I have been intrigued by Christopher Alexander’s writings, particularly the first two volumes of the Nature of Order where he explains the properties of designed (or architected) things which have life and processes for creating life.

It is just as important to look at process of creating good software as it is to consider what properties make software habitable for those who have to maintain it and keep it alive. While I appreciate process (and I think the agile community has given us a lot to consider) I am more keenly interested in exploring what makes complex software “living”.

Alexander identifies these properties (or qualities) of living things: levels of scale, strong centers, boundaries, alternating repetition, positive space, good shape, local symmetries, deep interlock and ambiguity, contrast, gradients, roughness, echoes, the void, simplicity and inner calm, and non separateness.

It can be easy picking to draw certain connections between certain “good” software design properties and Alexander’s list. For example, good shape, as others have pointed out can be a matter even as simple as properly indented a method. Or it can be more profound than that–leading you to break up a method into substeps and invoke helper methods, just to keep every step at a similar level of abstraction. I’m only giving you a taste to see whether you are interested in exploring these ideas further.

If you are, read my column, and also take a look at the C++ Report article by Jim Coplien on Space: The Final Frontier, which introduces Alexander’s notion of centers and how they relate to software structure, and peruse several very good blog entries by Regis Medina.

And if you are interested in exploring these ideas further, perhaps by taking a deep look into working code or frameworks or software that you consider to be particularly alive (or not)… let me know. I am considering finding a venue where software developers and designers and philosophers could concretely explore Alexander’s properties more thoroughly. I am not just satisfied to make those simple, easy connections and call it good. I want to challenge our best designs and see whether Alexander’s properties really do apply (or if we have some other properties that are more relevant).

Comparing Design Notes over Coffee

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My architect friend Ken and I had coffee the other day and caught each other up on the latest trends in our fields. Ken and his wife designed our house. Ken and I like to talk about meaningful design processes (me about software, Ken about buildings and homes) and learn from each other’s experiences.

I explained to Ken the new trend in software called agile development which emphasizes teamwork, close customer involvement, evolutionary design, programmers as designers, and incrementally delivering value to customers. On a typical agile team there isn’t much distinction between designing and programming. Design is viewed as something that is constantly happening while you are coding. In fact one view held by extremists that I find somewhat disturbing is to equate any design up front as being the same as Big Design Up Front which is equated with being wasteful. Since you will change your ideas during implementation anyway, why invest any time inventing pie-in-the-sky solutions? (In case you canâ’t tell, I take a more moderated view—it all depends on the situation and the context. I believe a little upfront design never hurts, and sometimes more is needed).

More traditional processes tend to divide development into phases: problem requirements are gathered and analyzed, solutions are designed and implemented. Although even that description is too simplistic. The Rational Unified Process talks about overlapping phases and delivering incrementally. So what’s the big difference between agile and more traditional approaches?

One big difference between agile and more traditional approaches is what stands between the developer and the problem. Traditional software development teams have analysts or business architects who gather requirements, write them down, and then work closely with developers/programmers who implement the software. These people hold the torch for what the user needs and wants (and can afford) throughout the process. The good analysts I know are skilled at talking with users and business experts and at translating their requirements into terms that developers understand. They bridge the complex world of the business and the detailed world of the programmer. On agile teams, developers work directly with their “customers”. Middlemen are eliminated. As little documentation as possible is created. There’s direct, open communication. The software design takes shapes in a very organic manner. Things are not planned out to the nth degree beforehand.

Ken noted that a similar trend in building architecture, especially the environmentally friendly architecture that he’s interested in. There’s the traditional design process which Christopher Alexander believes makes for lifeless buildings, and the more organic, buider-as-designer process (which is a haven for old hippies, according to Ken). It is into this world divided into disparate camps, that Ken wants to bring his creativity and vision. He’s worked in a big architectural firm and felt far removed from the customers’ needs. On the other hand, do-it-yourselfers tend to not want help. Where does such a passionate designer like Ken fit in and make a living? I told him he has to find a new market and educate potential customers on the benefits of taking responsibility and engaging in the design of their environmentally friendly homes with a designer like him.

I told him I find myself in a similar situation. But I haven’t had to create a totally new market. More often than not, I work with those who follow fairly traditional development processes. There I add value by talking about responsibility-driven design. I also help people who want to build flexible, well-designed systems get more skilled at articulating what they want and how to build it. I also try to bring a spark of agility to their processes—finding ways to simplify heavy-handed processes, streamline documentation, and communicate more effectively. I’d like to spend more time with agile teams helping them bring their design skills up another notch while programming like crazy. But so far, that opportunity hasn’t come along.

I’m always fascinated by the parallels between software and the architecture world that Ken and I find whenever we have time for a cup of coffee. My next challenge will be to absorb some of Christopher Alexander’s latest writing (but Ken has warned me that his four volumes are not light reading) before I have another conversation with Ken.