Wednesday, January 25, 2006

Kandt's SCM Best-Practices: Quality Practices

More from the paper Software Configuration Management Principles and Best Practices, by Ronald Kirk Kandt, appearing in the Proceedings of PROFES2002, the 4th International Conference on Product-Focused Software Process Improvement, Rovanieme Finland, December 2002.

In this article, Ronald Kandt describes ten basic principles that support configuration management activities, and then goes on to describe twenty three "fundamental" practices, which are split across the categories of: Management Practices, Quality Practices, Protection Practices, and Tool Practices.

In this entry, I'll enumerate Kandt's Quality Best-Practices for SCM (in priority order, with the most important ones listed first):
Practice 8:
All source artifacts should be under configuration control

Practice 9:
Use a Change-Control Board (CCB)

Practice 10:
Build software on a regular, preferably daily, basis, followed by invocations of regression test suites

Practice 11:
Document identified software defects

Practice 12:
Software artifacts that comprise a release should adhere to defined acceptance criteria

Practice 13:
Each software release should be regression tested before the test organization receives it

Practice 14:
Apply defect repairs to every applicable release or ongoing development effort

Most of folks in the "Agile camp" and in the "CM camp" would probably consider most of these to be "no brainers." The ones that Agilists might pick nits with are 8, 9, 11 and 14.
Control Contrarians and Wooden "Boards"

For 8 and 9, I don't think you'll find any agile folks recommending against the use of a version control system/repository. They would likely take issue with the appropriate meaning of "control." The words "control" and "change control" often set off sirens and red-flags for many agilists. And with good reason - they all too often see control attempted in a way that stifles developers and imposes highly restrictive waiting and redundancy for authorization/permission to do things; and they often see it executed as a means of preventing change instead of embracing it (see The Unchangeable Rules of Software Change).

Agilists also don't like the term CCB. Not only does the word "control" raise hackles (as already mentioned), but the term "Board" doesn't mesh very well with Agile values and perspectives on the whole concept of "team": a "board" conjures images of people isolated from the day-to-day workings and workers of the project. In reality, iteration planning meetings basically fill the CCB function for most agile projects because the iteration is usually small enough that there just isn't time to introduce new requirements within the iteration's timebox, so it's usually deferred to the next iteration.

Bugbases and Human Faces

There are many agilists who will rail against using a change/defect tracking tool. They say things like: there shouldn't be enough defects to warrant a bugbase (as opposed to a spreadsheet); rather than documenting and describing them in a database, we should just go fix 'em instead; index cards are a better for recording the bare essentials and promoting conversational dialogue and two-way face-to-face communication; tracking systems dehumanize communication and are too easily misused to the effect of hindering rather than facilitating dialogue and collaboration.

I understand all of these remarks and concerns. And while they all raise valid points, my own position is different. I consider a basic defect/issue/enhancement tracking (DIET) system to be every bit as essential as a version control tool. I still use index cards as a means of initiating dialogue and eliciting/capturing resulting needs and constraints. But then I put them into the tracking tool. Maybe if my handwriting were more legible the cards would be comprehendible enough to others, but I still think it's much more useful and convenient for tracking, organizing, sorting, searching, status accounting and generating reports (even if they just get posted to a local "information radiator").

I also think information about defects should be captured in order to identify and understand possible trends and root-causes, as well as provide evidence and history to consumers and customers (especially those requiring formal support/service-level agreements).

I do think a lot of change control implementations (and resulting tool customizations) make things harder on developers than needed, for the sake of convenience to other roles. I think that's what leaves the bitter taste in many agilists mouths and why they dislike it so much - because it holds them back and/or diverts them away from what they feel is most important: delivering value to the customer in the form of tangible, tested results. I think that's a shame because I think it doesnt' have to be that way. A few tracking tools are gaining popularity in the Agile arena, like VersionOne, and Jira.

The Monstrosity of Multiple Maintenance

Okay - I don't think that any agilists will say that a defect shouldn't be fixed in all applicable release. What they will say is that they would first do everything in their power to have one and only one mainline of development. Branching a new mainline to support a legacy release or a market/platform/project-specific variant is anathema for most agilists: it creates redundancy among code-streams (fixes have to be applied and integrated more than once) and splits the value-delivery stream into isolated streams/teams of diminished capacity.

Agilists would prefer to see a solution at a later binding time that uses design patterns of software architecture, building/releasing, licensing/distribution, & install/upgrade rather than patterns of version branching. For the most part I agree with them, but I am less wary of branching in the case of parallel development (because I know how to do it really effectively), and I am perhaps more accepting of the case of multiple releases (but I would still fight like heck against multiple variants :-)

Next up, we'll look at what Kandt identifies as Protection practices in his list of 23 SCM best-practices.

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