SATURN 2019 Workshop - Survivor: Architecture Island

This year’s workshop at SATURN asked its participants to narrow the long list of architecture ideas, much like the TV show Survivor. Our hope was to arrive at a short list we could use to teach newcomers.

What we discovered was that there were core ideas but they varied by the makeup of the team (experienced, distributed, etc.) and by the kind of project (safety-critical, IT, etc.). This was interesting and raises some good questions to dig into.

Here are the fantastic slides (major kudos to Michael Keeling for the content and visuals):

I wrote a position paper (also on the workshop’s Github page) to get us started on the list of ideas.

What are the big ideas in software architecture?

George Fairbanks

3 May 2019

In this workshop, we’ll be discussing which ideas about software architecture we’d keep and which ones we’d be forced to abandon as we confront the dangers on Architecture Island (rather like the TV show Survivor). It seems like a good idea to survey some of the most popular books on software architecture to create an inventory of what ideas we are starting with.

I intended to survey about a dozen books but it took more time than I’d expected so I (so far) have only done two plus my Intro to Software Architecture lecture from 2012. For this workshop, any list is better than no list, but I’d find it interesting to see which ideas span all or most of the books on software architecture.

I picked up Documenting Software Architectures (2nd edition) first as I remembered it as being much like a catalog itself. I skimmed the book and jotted down ideas or topics. There’s a fair amount of bias in this activity: in my haste I may not have noticed an idea, a different reader might notice different ideas, and of course names differ across books and I was trying to align them while jotting down notes. Then I did the same for Software Architecture in Practice (3rd edition) and my intro lecture. I merged those lists into a table, doing some more subjective merging and omitting of topics. If by chance any of the workshop participants notice errors or omissions (I’m looking at you Len Bass) then please let me know and I’ll fix up the table.

Notation: A question mark in the table indicates that I don’t think the topic was covered but I wouldn’t be surprised if I’d overlooked it. The asterisk in the table is meant to be a bullet that nests under the line above, but my efforts to make it render that way have not yet worked.

I included that intro lecture not because it’s in the same league as the two books but because as of 2012 it was my idea of what I’d keep on Architecture Island and I was curious what I’d left out.

Topic DSA 2nd Edition SAP 3rd Edition Intro to SA
Views (module, C&C / Runtime, Allocation) Yes Yes Yes
* Master model unifies views No No Yes
Stakeholders Yes Yes No
Quality attributes (vs functionality) Yes Yes Yes
* Architecture inhibits or enables Yes Yes Yes
* Tied to failure risks ? ? Yes
Requirements: QA vs feature Yes Yes Yes
* QA requirements drive architecture Yes Yes Yes
* QA scenarios No Yes Yes
* Argument: How this architecture meets requirements Yes No No
* Architecturally significant requirements (ASRs) ? Yes Yes
Architecture is a subset of design Yes ? Yes
Contexts: Technical, lifecycle, business, professional No Yes No
Architectural styles / patterns Yes Yes Yes
* Module style: decomposition, uses, generalization, layers, aspects, data model Yes No No
* Runtime style: pipe and filter, client-server, peer-to-peer, SOA, pub-sub, shared-data, multi-tier Yes No No
* Allocation: deployment, install, work assignment Yes No No
Tactics No Yes No
* Attribute driven design No Yes No
Architecture diagrams (vs cartoons) Yes ? No
Notaions and ADLs: element catalog Yes No No
Product line architectures Yes Yes No
Architectural decisions Yes ? No
* Rational architecture decisions No No Yes
Interfaces: provided and required Yes No No
Design reviews Yes Yes No
Align architecture and business goals No Yes No
Tradeoffs (and ATAM) No Yes Yes
Separate: Architecture, architects, architecting No Yes Yes
Constraints / guiderails Yes Yes Yes
Conceptual model of architecture Yes Yes Yes
Architecturally evident coding style No No Yes
Architectural hoisting No No No