1 year, 3 months ago

Holistic Architecture – Keeping the Gears Turning

Link: https://genehughson.wordpress.com/2017/06/14/holistic-architecture-keeping-the-gears-turning/

Gears Turning Animation

In last week’s post, “Trash or Treasure – What’s Your Legacy?”, I talked about how to define “legacy systems”. Essentially, as the divergence grows between the needs of social systems and the fitness for purpose of the software systems that enable them, the more likely that those software systems can considered “legacy”. The post attracted a few comments.

I love comments.

It’s nearly impossible to have writers’ block when you’ve got smart people commenting on your work and giving you more to think about. I got just that courtesy of theslowdiyer. The comment captured a critical point:

Agree that ALM is important, and actually also for a different reason – a financial one:

First of all, the cost of operating the system though the full Application Life Cycle (up to and including decommissioning) needs to be incorporated in the investment calculation. Some organisations will invariably get this wrong – by accident or by (poor) design (of processes).

But secondly (and this is where I have seen things go really wrong): If you invest a capability in the form of a new system then once that system is no longer viable to maintain, you probably still need the capability. Which means that if you are adding new capabilities to your system landscape, some form of accruals to sustain the capability ad infinitum will probably be required.

The most important thing is the capability, not the software system.

The capability is an organizational/enterprise concern. It belongs to the social systems that comprise the organization and the over-arching enterprise. This is not to say that software systems are not important – lack of automation or systems that have slipped into the legacy category can certainly impede the enterprise. However, without the enterprise, there is no purpose for the software system. Accordingly, we need to keep our focus centered on the key concern, the capability. So long as the capability is important to enterprise, then all the components, both social and technical, need to be working in harmony. In short, there’s a need for cohesion.

Last fall, Grady Booch tweeted:

Ruth Malan replied with a great illustration of it from her “Design Visualization: Smoke and Mirrors” slide deck:

Obviously, no one would want to fly on a plane in that state (which illustrates the enterprise IT architecture of too many organizations). The more important thing, however, is that even if the plane (the technical architecture of the enterprise) is perfectly cohesive, if the social system maintaining and operating it is similarly fractured, it’s still unsafe. If I thought that pilots, mechanics, and air traffic controllers were all operating at cross purposes (or at least without any thought of common cause), I’d become a fan of travel by train.

Unfortunately, for too many organizations, accidental architecture is the most charitable way to describe the enterprise. Both social and technical systems have been built up on an ad hoc basis and allowed to evolve without reference to any unifying plan. Technical systems tend to be built (and worse, maintained) according to project-oriented mindset (aka “done and run”) leading to an expensive cycle of decay, then fix. The social systems can become self-perpetuating fiefs. The level of cohesion between the two, to the extent that it existed, breaks down even more.

A post from Matt Balantine, “Garbage In” illustrates the cohesion issue across both social and technical systems. Describing an attempt to analyze spending data across a large organization composed of federated subsidiaries:

The theory was that if we could find the classifications that existed across each of the organisations, we could then map them, Rosetta Stone-like, to a standard schema. As we spoke to each of the organisations we started to realise that there may be a problem.

The classification systems that were in use weren’t being managed to achieve integrity of data, but instead to deliver short-term operational needs. In most cases the classification was a drop-down list in the Finance system. It hadn’t been modelled – it just evolved over time, with new codes being added as necessary (and old ones not being removed because of previous use). Moreover, the classifications weren’t consistent. In the same field information would be encapsulated in various ways.

Even in more homogeneous organizations, I would expect to find something similar. It’s extremely common for aspects of one capability to bear on others. What is the primary concern for one business unit may be one of many subsidiary concerns for another (see “Making and Taming Monoliths” for an illustrated example). Because of the disconnected way capabilities (and their supporting systems) are traditionally developed, however, there tends to be a lot of redundant data. This isn’t necessarily a bad thing (e.g. a cache is redundant data maintained for performance purposes). What is a bad thing is when the disconnects cause disagreements and no governance exists to mediate the disputes. Not having an authoritative source is arguably worse than having no data at all since you don’t know what to trust.

Having an idea of what pieces exist, how they fit together, and how they will evolve while remaining aligned is, in my opinion, critical for any system. When it’s a complex socio-technical system, this awareness needs to span the whole enterprise stack (social and technical). Time and effort spent maintaining coherence across the enterprise, rather than detracting from the primary concerns will actually enhance them.

Are you confident that the plane will stay in the air or just hoping that the wing doesn’t fall off?