A Trace in the Sand

by Ruth Malan





Architects Architecting Architecture  

May 2014



More on Design and Testing

The other day, Dana said "But, of course! All design is testing." That wasn't so obvious to me, but I hold Dana in (very) high regard, so I thought about it. Elaborating on the design characterization in the above trace, *...design

  • establishes (understands and ascertains what is relevant in) context,
  • understands and articulates/constructs intention (desired outcomes, capabilities and properties),
  • surfaces grounding assumptions, makes assertions (what we hold to be true) and projections (seeks out trends and shaping forces), identifies challenges to be addressed
  • negotiates boundaries (negotiates/assigns shapingly significant roles/responsibilities, makes trade-offs across boundaries)
  • designs interaction surfaces and interactions across the boundaries to achieve the intention, and
  • addresses how the intention will be delivered -- and associated challenges tackled (forces resolved/balanced)...*

Design iterations (*...*) are messy, incomplete, and, while there is some "recursion" implied by that last bullet, it is not not not strictly hierarchical or "top-down." Where our design attention moves and what design medium we use (including, but not limited to, tests and code), is a judgment call (the extraordinary moment principle). Not only is there working at different scopes (sometimes "high level" and sometimes in the details, creating/evolving the "big picture" sometimes, coding units, building features/slices/services, etc., at others) as guided by judgment calls, but we also design across different facets, taking different (cross-cutting) concerns into account, and taking these different dimensions into consideration separately, sometimes, and together, sometimes. Accommodating for our (un)bounded (ir)rationality, for novelty and complexity, for multiple perspectives, and more.

And part of the design loop is testing -- ascertaining as appropriate to the design stage, if the design is on the right track [iterating between "right system" (fit to context and to purpose) and "built right," as there are trade-offs between what we are building and how it is built that ripple across not just what it is but how it works, and what it costs, and what the challenges are, and such]. That is, we're not simply elaborating the design. We're uncovering and resolving design trade-offs, assessing how we're doing against complexly interacting desired outcomes of various stakeholders, even as those outcomes come into clearer focus and potentially shift. We're learning -- about the context)s) into which the system will fit, what the system needs to be, and how best to accomplish that. So we may back-track, try different approaches. What makes it a design "loop" -- and one that may result in backtracking -- is the "testing," the probing for how we're doing so far, exposing our design to scrutiny and improvement. The style of testing will depend on what we have to test. If it's just a sketch prototype, the nature of our testing is rather different than if we have incremental builds of an evolving system. If our design process is to be responsive to finding things out, we're testing. Testing -- one could say challenging -- our ideas of what is needed. Testing our ideas of how best to create what's needed, solving the problems and addressing the inherent challenges and testing how well we did that.

We design to get more the outcomes we want, which has implicit in it the notion that it is not gobsmack easy connect-the-lego-blocks-into-a-simple-prefab-structure kind of thing. desiging is testingSo we design to figure out the outcomes as well as how to achieve them, and we improve the design to get more what we want.

It is built into the very notion of design that we test. We probe, we explore, we verify -- we test to improve, not simply to prove or establish that we did it "right" and are getting expected results. And we may leave a scaffolding of tests around the design frames (at different scopes), so we can verify that changes within a frame still work within the commitments of the frame. (Alternately, they form a "regression bedrock.")

"Sweetness," as coined by Michael Feathers, is "when a single mechanism satisfies many different needs in an elegant way." Unit testing in the TDD mode has that kind of sweetness. We design a unit that has intentionality and commitments and a boundary (what's in/responsibilities and interaction surface/I/F and protocol; and we may be thinking in terms of boundary conditions and containment of side-effects, etc.), and our design thinking there does double duty, establishing how we will test that unit. And thinking about testing that chunk of intentionality or design commitment, helps us improve the design, so that it is more than just a means to establish that the code is delivering to its commitments (once first built, and as it is evolved and refactored).

But sketch-prototyping does (more than) double duty (i.e., has sweetness) too. Models that lead to simulations, too. Because outcomes arise emergently from interactions and collaborations among various "units," and we don't have all the units a priori (even when we're evolving a system, we don't have the new endpoint, upfront).

We model to think, to create a shared thoughtspace where we can think together about the form and shape and flow of things, the how-it-works things both before we have code and when the very muchness of the code obfuscates and it is all too much to hold in our head, and we need to think about interactions among, cross-cutting concerns, how things work together, and such. And models help persist our thinking -- informally sketched and preserved as digital photos we slap into the project memories "scrapbook"... or more formally, as models we tech up, if circumstance warrants the extra degree of ceremony and/or formality and/or blueprint-y precision. And they help us test our ideas -- in an exploratory way when they are just sketches, but also as simulations. They help us decide what to instrument, to make visible. If you need some nudging along the lines of models help us see, or notice, help orient us to observing::

Drawing is good training in the art of seeing. And sketch-modeling systems is good training in noticing the relationships between structure and function, noticing relationships that give rise to and boost or damp properties, and so forth.

At any rate, we design. We utilize abstractions at different design scopes and in different ways. We test to probe, to learn, to verify the efficacy of the abstractions under multiple simultaneous demands (for they deliver capabilities and qualities of our system). We evolve the design. We factor and refactor; we reify and elaborate. We test and evolve. We make trade-offs and judgment calls. We bring what we can to bear, to best enable our judgment, given the concerns we're dealing with. Sure. It's kind of messy. Kind of wicked. Kind of crucial! We test. That is we probe. We instrument. Variously. Software is a highly cognitive substance with which to build systems people and organizations depend upon. So. We design-test our way, with different mediums to support, enhance, stress and reveal flaws, etc., etc., in our thinking. We probe. We reason. We verify. Not using sketch-prototypes to do A/B field testing. Using judgment. Naturally! (Yessss! Judgment factors. And factors and refactors. But also tests. Informally. And more formally. As fits the extraordinary moment. ;-)

Uh. Now I have to test if that is what Dana meant... Hey I try. Some people call it failing, but I call it trying. I try. And I try. We have to try different things, from different angles, experiment our way to learning and figuring out what we want and an approach to getting it more the way we want it to be. And in this case, I want to learn. So I try. Try to understand. Try to get my understanding expressed, and tested for clarity and serviceability. And so forth. I try. Okay. I try.

Oh. And Tom Graves says I'm eminently quotable so I tried that too -- I quoted myself in a call-out. ;-) Smiles. Thanks Tom. And Gene. Hugs and skips of gratitude. You give all my hours of trying a rewarding moment of blissful recognition of peership on this shared flight on spaceship earth.

5/12/14: Thanks to Paul Harland for the conversation on this topic. It is nice to be taken seriously enough to have some discussion that furthers my ideas. Paul will no doubt see his influence in this trace, and I'm grateful -- thanks Pablo. :-)

5/20/14: Allowing that TDD pushes design, it is just one scope and frame of design.

While we're bringing babies back, let's bring back the notion that code is not the only design medium. Oh sure, code and tests have that beguiling "sweetness." But models have sweetness too. Not one or the other. Not BDUF. But let's allow that models help us push testing to broader scopes and earlier -- to test ideas. Sure. We have to loosen up our notion of testing, but we do so to allow ourselves the benefit of probes for direction, so we can test drive our strategy cheaply and quickly, before it is hard-cast in organization and code structures, with all their coupling -- intended and un, including to assumptions, explicit and im. Which is a nice segue to the next trace. ;-)

5/20/14: It occurs to me that those who thrust their preconceptions onto me, may think that my design loop (iterating between the *s in the 5/9/14 tracelet above) implies top-down. No no! Fractal and Emergent -- remember? And messy! At times. We seed with a notion of significant abstractions, and we factor and refactor, seek out abstractions and design mechanisms -- proactively, and with the benefit of hindsight. That is, we bring learning from past and peer projects. And we learn as we go. We try things out. Yadda.

Oh. You should read this:

  • Emergence and Failures of Discipline


Now you understand my traces. ;-)

Oh. And read, or reread, this: Fractal and Emergent. Yes, it is that good. How good? Worth giving your contact info to get, duh. Hey. Think short ebook, written by the awesome (trumpets please) moi and db. For just the price of your contact info. Heck, you'd have to give that if you paid with your credit card. But the fractal and emergent, strategy and architecture in tandem, etc., ideas are that important, and it's so, you know, wonderfully written. (cue more trumpets).


5/31/14: See also:

  • The Making of a Software Wind-Tunnel part 1, part 2 and part 3. by Mark Burgess

PS. I'm beginning to think "is dead" doesn't mean what we you think it does. It means it has entered middle-age and settled in to a responsible life.



Conway's Law Reverb

Since Conway's Law is in the air again, you might like to catch up on all the awesome I've written about it (smiles):

  • Conway's Law, February 13, 2008 [implications of Conway's Law]
  • Conway's Law, 2/20/14 [collection of links and observations]
  • Conway's Law-ish, 5/8/13 [Conway's Law and negative space]
  • Conway's Law, 10/26/12 [explores the link to Innovator's Dilemma further]
  • Architecture of Responsibility, 3/14/11

Tl;dr? Here are some highlighter quotes:

"if the architecture of the system and the architecture of the organization are at odds, the architecture of the organization wins" -- 2/13/2008

They will co-evolve, because if they don't, Conway's Law warns us that the organization form will trump intended designs that go "cross-grain" to the organization warp. -- 12/17/13

It means that system architects (who we call architects) and business/organization architects (who we call managers) should not work as if one has no impact on the other. -- 2/13/2008

And as put by the inimitable Michael Feathers:

Conway's Law by @mfeathers - "you always ship your organization, so design your organization well" #craftconf -- 3/24/2014

That statement is awesomely profound/has far-reaching implications. Just think about all the "360 degree view of the customer" and "single authoritative data source" efforts we've had to go through. Again. And again. Because the organizational silos around the different lines of business are apparent to incredulous customers confounded by the lack of integration (of information and products) across services from the "same" company... Organizational divides and "silos", from teams to divisions or lines of business, show up in what we provision, from services or products to solutions or systems-of-systems, in the ecosystem.

Michael Feathers used the notion of echoes to talk about how organizational and process influences show up in the code.

Politics echoes:


Politics plays a huge role. And a lot of the role it plays is in what it silences. But we don't know the stories of silence. -- 5/8/13

The point that I was making there, is that we only get a very partial view of the history. Echoes, like rings in tree that tell history

Process echoes:

  • Michael Feathers "Process Echoes in Code" talk at TICOSA

Image right: from mfeathers talk "Conway's Law and You" (insightful; Michael structures his talks with implications and guidance)

So, we can sniff out the echoes, do some archeology, but are they enough to understand the influences, direct and indirect, intended or un, that shaped the code?

[Opportunity for] Symbiosis:


Allan Kelly's Conways Law & Continuous Delivery slideset points to his contributions to the industry understanding of Conway's Law and it's implications, both direct and in dual and corollary form.

And here are some thoughts scooped up from traces over the years:

"Piecemeal growth, or incremental development, is not just desirable but a fact of life in software (even big-bang first releases are evolved thereafter). Even so, we need to build more learning into our process. More learning when it is cheaper to find and fix problems with the vision (doing course corrections toward "right system") and structure (built right). Then, accepting that we will continue to learn and evolve our system, we need to invest in fixing the mistakes—incrementally adding functionality yes, but repairing structural defects too. This investment is the crucial dual to piecemeal growth that we too often forget in software. When we keep marching to a frenetic "add value" drumbeat, we get into a situation where the system threatens to crumble under the mass of deferred structural issues (like the Minneapolis I-35W Mississippi River Bridge that collapsed last year)." --- moi


'The system has to bear the "weight", so to speak, of features that delight users (and functions they rely on but barely notice unless we mess up). Hence, the system must have structural integrity which raises different arenas of attention and competency than coding the features. That is, it requires attention to emergent properties associated with resilience and scalability and evolvability and such. Properties are emergent; they arise dynamically from the structure (elements and relationships) and mechanisms (interacting elements, designed to accomplish some function addressing, often, a cross-cutting concern) of the system. But architecting is not just about structural integrity -- or we could just call the role structural engineering and be done. Architecting is about the design of the system to achieve (more) its desired outcomes across the contexts of relevance -- various contexts of use, as well as operation and evolution. And architecting is about bringing insight to the strategy table when those desired outcomes are shaped.' -- 5/16/12


"If we recognize that we have threaded two processes together and then turned a blind eye to their different needs, we have the chance to do something about it! Two processes?

  • Invention and discovery, not just of user needs but of approaches or mechanisms for addressing those needs -- discovery of how to make it work.

  • And engineering of a system with integrity.

Going from the messiness of our discovery-oriented process to the well-factored, tested integrity of our engineered system shouldn't be considered rework or waste! Unless we leave it until after it has sorely impacted users and our business viability. That is waste.

As we proceed in the fog of uncertainty, entropy grows -- and produces more fog! Under uncertainty we "give things a try"; accept good enough, and try the next thing. As entropy grows, it introduces its own uncertainty..."    -- 10/5/11

That is, there is a relationship between the architecture of the organization (and its communication flows) and the architecture of the system (and its boundaries and flows). We need to take this into account, to reap synergies rather than doing the harder thing, trying to "swim against the current." Oh yeah, and this:

Guidelines for the Architecture:

ABATIS, n. Rubbish in front of a fort, to prevent the rubbish outside from molesting the rubbish inside. [a more realistic name for "bridge," GoF?]

RESPONSIBILITY, n. A detachable burden easily shifted to the shoulders of God, Fate, Fortune, Luck or one's neighbor. In the days of astrology it was customary to unload it upon a star. [this relates to refactoring, which, given the preponderance of intent over action, may be defined as shifting the responsibility to factor onto Fate, Fortune, Luck or one's neighbor.]

-- The Devil's Dictionary [(playfully) related to architecture], 10/10/09

Abatis? See points mfeathers makes about interfaces between teams.

Refactoring is the corollary to piecemeal growth, allowing entropy containment. But we have to refactor the organization too? If it would subvert the system (re)design and evolution.

Death Star architecture yet..


5/7/14: Michael Feathers used the tree rings metaphor in his "process echoes" and "symbiosis" talks. So my "what I'm paying attention to shapes what I perceive and pay attention to" mind noted:

  • "Years" an audio recording of tree rings being read by a computer and turned into music
  • Identifying Wood: Accurate Results With Simple Tools, R. Bruce Hoadley [which we have because -- see next bullet]
  • Visualizing Structure

I should return to that Software Visualization work -- I think there is a lovely book in it. But first, sigh, that neverending Architecture story. ;-)

5/9/14: Two great additions to the Conway's Law insight crucible:

5/24/14: Very nice application of Conway's Law-derived insights to microservices and "granularity" decisions, given organizational considerations by Gene Hughson (my italics):

"Composing a system of independent, autonomous components, as opposed to a monolith, allows them to be partitioned by business capability as well as be developed and maintained by a permanent team. This transforms Conway’s Law from an observation about the nature of software systems into a principle that can be used to improve the structure of those systems (“The organizational divides are going to drive the true seams in the system.”). The social system architecture will influence the software system architecture in any event, the question is whether that influence will be intentional or not."

-- Gene Hughson, Carving it up – Microservices, Monoliths, & Conway’s Law, 5/24/2014

Great add to the symbiosis conversation, and tie-in to microservices.

Hey, so I snipped another nice add to the conversation:



Conway's Law

6/1/14: The question of self-organizing teams is interesting, in this context.... Tangentially related (well, it just touches at the point of self-organizing, so this seems like a good placeholder for it):

6/22/14: Related:


7/3/14: Playing well together:

As I pointed out early in the above trace, integrating across organizational divides is a challenge and... when left to happy accident, may well have all the smack of accident rather than design -- as in, designed to get more what we want, looking for consequences so we get less unintended side-effecting from being system-blind.

8/1/14: Collection of observations on Conway's Law (via Rachel Davies):

  • SPA2014 Implications of Conways Law


10/7/14: A few more links (because... you're that curious/investigative):

"Organizations for a few years now have understood this link between organizational structure and software they create, and have been embracing new structures in order to achieve the outcome they want. Netflix and Amazon for example structure themselves around multiple small teams, each one with responsibility for a small part of the overall system. These independent teams can own the whole lifecycle of the services they create, affording them a greater degree of autonomy than is possible for larger teams with more monolithic codebases. These services with their independent concerns can change and evolve separately from one another, resulting in the ability to deliver changes to production faster. If these organizations had adopted larger team sizes, the larger monolithic systems that would have emerged would not have given them the same ability to experiment, adapt, and ultimately keep their customers happy."

-- Sam Newman, Demystifying Conway's Law

And the awesome:

"The responsibility of architecture is the architecture of responsibility" -- Jan van Til

which I quoted in my Architecture of Responsibility trace, which should have you hightailing it over to my Conceptual Architecture write-up.


Marick on Conway

I responded with a pointer to this trace because "you always ship your organization" (feathers) and the subsequent paragraph is one elaboration. And added that I have my own hypotheses about how Twitter is organizaed, given, for example, how DM content is staged and delivered up so differently across browsers/devices. (But I didn't get a response and then I felt like it was rude to barge in on a side convo even if it showed up in my stream because I follow both. So I deleted my tweet so as not to intrude longer on a stranger's interaction line. Twitter is hard. I'm not socially adept, so I don't know what's impolite...)

11/25/15: And this is great:

Also, from the man himself:

  • October 2013 keynote at RESER2013 on Conway's Law 50 years later (.pdf), Melvin Conway

And if you want to see what Mel Conway has been up to more recently (hint: Worry Dream/Bret Victor and visual thinking comes to mind):

  • Think About, and Build, Interactive Applications By Wiring Up Flow Components (.pdf), Melvin E. Conway



Yesterday I learned:

Origin of NEGOTIATE: Latin negotiatus, past participle of negotiari to carry on business, from negotium business, from neg- not + otium leisure — more at negate First Known Use: 1599






I also write at:

- Bredemeyer Resources for  Architects





Ruth Malan has played a pioneering role in the software architecture field, helping to define architectures and the process by which they are created and evolved, and helping to shape the role of the software, systems and enterprise architect. She and Dana Bredemeyer created the Visual Architecting Process which emphasizes: architecting for agility, integrity and sustainability. Creating architectures that are good, right and successful, where good: technically sound; right: meets stakeholders goals and fits context and purpose; and successful: actually delivers strategic outcomes. Translating business strategy into technical strategy and leading the implementation of that strategy. Applying guiding principles like: the extraordinary moment principle; the minimalist architecture principle; and the connect the dots principle. Being agile. Creating options.

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Copyright © 2013 by Ruth Malan
Page Created:July 1, 2013
Last Modified: September 9, 2020