Systems Thinking Complicates Things

4th UK Rock Paper Scissors Championships by James Bamber via Wikimedia

 

I’ve had the honor and pleasure of appearing as a regular on Tom Cagley‘s SPaMCast podcast for almost three years now. Before I write one of my “Form Follows Function on SPaMCast x” posts, I always listen to the podcast to make sure that the summary is right (the implication being, relying purely on my memory won’t be right). I got a bonus while writing up last week’s appearance, because Tom asked an excellent question that deserved its own post: does thinking about a problem (legacy systems, in the instance of last week’s discussion) holistically/systematically complicate things?

Abso-freakin’-lutely.

It is much easier to avoid all the twists and turns and possibilities inherent in systems thinking. A simpler approach, picking one lever to pull/one button to push, makes it much easier to come up with a solution.

It just doesn’t work very well at coming up with solutions that actually work.

When there is a mismatch in complexity between problem and solution architectures, this mismatch will be an additional problem to deal with. This will apply when the solution is more complex than the problem space warrants and when the opposite is the case. Solutions that fail to account for the context they will encounter are vulnerable. This is the idea behind the quote attributed to Albert Einstein: “Everything should be made as simple as possible, but not simpler.”

Human nature can push us to fix problems quickly, and quick will generally equate to simple. It takes time to analyse the angles and consider the alternatives. How often have you seen people ask for “the best” way to do something absent any context? How often have you seen people ask “why would someone ever do that?”

I’ll answer that by asking 3 questions:

  • since Rock beats Scissors, why would anyone ever choose Scissors?
  • since Paper beats Rock, why would anyone ever choose Rock?
  • since Scissors beats Paper, why would anyone ever choose Paper?

Reality isn’t binary. It’s not what’s “best”, it’s what’s fit for purpose in a given context and there are lots and lots of contexts out there.

This isn’t to say that all quick, simple interventions are wrong. If you find yourself in a house fire, more action and less comprehensive deliberation may well be in order. The key is matching the cost (largely in terms of time) of defining the problem space with cost (in terms of both effort and risk that the intervention adds to the problem) of crafting the solution.

Rock, Paper, Scissor, Lizard, Spock rules diagram

It’s almost guaranteed that the system contexts we deal with (both technical and social) will evolve toward more and more complexity. Surprises will emerge as a matter of course. We don’t need to make more by failing to take a more holistic view when we have the time to do so.

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Form Follows Function on SPaMCast 454

SPaMCAST logo

I’m back for another appearance on Tom Cagley’s Software Process and Measurement (SPaMCast) podcast.

This week’s episode, number 454, begins with Tom talking about iteration planning. Jeremy Berriault comes next with a segment on QA team leads and I bat cleanup with a Form Follows Function installment based on my post “Trash or Treasure – What’s Your Legacy?”.

Tom and I discuss the concept of legacy systems: what they are, whether they’re trash or treasure (sometimes both), and how they impact an organization.

You can find all the SPaMCast episodes I’m in under the SPaMCast Appearances category on this blog. Enjoy!

Microservices or Monoliths – Fences and Neighbors

Photo of fence separating fields from a road

 

At the end of my last post, “What Makes a Monolith Monolithic?”, I stated that I didn’t consider the term “monolithic” to be inherently derogatory. It is, rather, a descriptive term relating to the style of organizing an application’s architecture. Depending on the context the system operates within, a monolithic architectural style could lie anywhere on the continuum between perfectly suited and perfectly disastrous. Placing it on that continuum requires a sense of what qualities are most needed or desired and which can be traded off in their stead. Everything comes with a cost, and attempting to ignore that fact merely sets us up for unpleasant future surprises.

After an initial period of unbridled enthusiasm, opinion seemed to gel around the idea that highly distributed application architectures (aka microservice architectures) were not suitable to all contexts. There are prerequisites for jumping into the microservices pool in terms of problem architecture, infrastructure, and organization. Attempting to shoehorn a microservice architecture into an environment that cannot support it will be overly expensive at best and a failure of apocalyptic proportions at worst.

There are many aspects of application design that are commonly recognized as beneficial: modularity, loose-coupling, high cohesion, and separation of concerns. It is critical to realize that these aspects can be found in systems with microservice architectures, monolithic systems, and everything in between. Distributed architectures are not necessary for modularity, nor any of those other aspects. In fact, one could easily create an application with a microservice architecture whose qualities are opposite to these desirable ones.

There are, however, situations where the benefit of a microservice architecture outweighs the costs and complexity. The ability to independently deploy and scale the various parts of an application is a major benefit, in my opinion. A well designed microservice architecture can even allow for the components of an application to be replaced on the fly. These features are not unique to microservice architectures, but are arguably easier to achieve than in other application architectures.

Real design, balancing both costs and benefits, is required. Sticking a bit of network in between the components is insufficient to ensure success. Deliberate design, especially as the boundaries multiply, is critical for an effective system. Identifying and providing for those boundaries at the conceptual level (i.e. before they become physical) is key. Good fences can either make for good neighbors, or they can create a maze of barriers.