Yesterday I was a panelist for a Webinar on agile tools, focusing on software configuration management (SCM), build and software process automation (SPA), the latter term referring to the set of defined, repeatable and measurable automated development workflows that engineers use to transform requirements into shippable software products. Contrary to what I’ve read about the disdain that some agile devotees have for tools, most of the attendees were hungry to know what features their SCM tool should have in order to support agile software development and SPA. Here are some of the highlights, and of course, my take on why I think AccuRev is the best tool for agile software process automation.
There are five key feature areas that an SCM tool needs to support in order to be ready for agile:
* Support for flexible process models
* Continuous integration support
* Support for issue-based development
* Efficient branch and code management
* Private version controlled developer workspaces
Let’s take a look at each of these in turn.
* Support for flexible process models. Agile is often one of several processes being employed within a software development organization. Unless your SCM tool is flexible and process-neutral, you will have a hard time implementing agile (say, for product development) and more traditional processes like waterfall (for example, for product maintenance work) in the same SCM tool. AccuRev streams are a natural way to model any process, and thus are a good fit when agile needs to coexist with other development processes. As for software process automation (SPA), AccuRev streams again are a great fit, since they enable users to model any arbitrary stages of code transformation that a development team sees fit to define as part of their process. By adding triggers and workflow to a stream hierarchy, teams can implement SPA directly in AccuRrev.
* Continuous integration support. Continuous integration is one of the core process elements associated with agile development. By building and testing frequently and acting on the results of tests, teams can uncover defects or test gaps earlier in their development cycle, saving time and money compared to such discoveries late in the cycle. But continuous integration goes beyond just testing the nightly build. With multi-stage continuous integration in AccuRev, code is automatically promoted up the stream hierarchy into more stable configurations as it passes tests. At each stage, continuous integration takes over to build and test, typically with a wider scope of testing as the code nears the release stage. Legacy SCM tools make this type of automated integration factory somewhere between difficult and impossible due to the complexity involved in setting up the hierarchy and in automatically moving and merging code as it flows up the hierarchy.
* Support for issue-based development. Apparently there is a lot of contention about the need for filing issues and defects in agile development. This has puzzled me greatly. While I’m in favor of developers identifying and fixing issues as they are discovered, you lose valuable process information when a defect or enhancement ticket is not filed and later associated with a code change. Without an issue that describes what the problem was, someone looking at the code changes for audit purposes or for group code reviews is at a disadvantage. Why was this code change made? Is it related to other changes? How long did it take? Was it done to fix a bug or to add a feature. In AccuRev, issues either in the integrated AccuWork issue tracking system, or in a 3rd party issue tracking system, can easily be associated with code changes via the AccuRev Change Package mechanism. This establishes basic traceability between issues and the code changes that developers make in order to satsify the requirements of those issues. Issue-based development is well-defined, repeatable and measurable – all hallmarks of good software process automation.
* Efficient branch and code management. Any time you’re working on more than one project, you need to isolate that project’s code from other projects. With agile and multistage continuous integration, even a single project requires multiple code lines in order to separate in-progress code from unit tested code from system tested code that is ready for release. If an SCM tool makes branching, merging and labeling difficult, teams tend to practice branch avoidance, which I sometimes like to call “fear of branching.” This is a classic example of letting a tool dictate what processes you can implement. In AccuRev, streams replace branches as the mechanism for isolating codelines. Since streams are represented inside of AccuRev as data separate from the actual file versions, creating streams is fast – really fast, like, a second or two – and managing a system with hundreds of streams spanning multiple projects and processes is easy. For continuous integration, AccuRev snapshots and time-based streams are also fast and easy to create and manage, and give users a straight-forward way to “label” an interim or milestone codeline without having to place markers in thousands of source files.
* Private version controlled developer workspaces. Software developers are the heartbeat of any engineering organization. Executives at any development shop will tell you that hiring talented engineers and keeping them well-tooled and productive is the single largest challenge that they face. For agile, this is even more of a challenge, since coding cycles tend to be shorter, and thus anything that gets in the way of individual or team productivity tends to have a greater negative impact on the project. Private version controlled workspaces like the AccuRev workspace model improve productivity, since they enable developers to work in isolation (while they are ‘heads down’ coding). Private workspaces in AccuRev also give developers full SCM capabilites in their workspaces without the need to share in-progress code prematurely. By using the ‘keep’ operation, developers make safe copies of their work in the AccuRev repository, and later can ‘promote’ the code to an integration stream to combine their work with that of their teammates. Individuals are more productive in this way, and if continuous integration builds are frequently testing the integration stream, so are teams.
In a nutshell, agile requires tools, and these tools need to support different modes of operation than with other processes. SCM can help or hurt you in setting up and executing an agile process, so these guidelines are a way to help you get your SCM tool ready for agile - easy of course if your tool is already AccuRev!
If you’re interested, you can view the webinar recording.
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AccuRev streams are actually TOO agile. While the promotion-and-inheritance model works really well when the stream configuration is stable, it can get very confusing very quickly when the configuration is in flux. AccuRev doesn’t record enough information about stream moves, etc. to be able to understand what happened six months ago. And it’s always the case that when you’re asking that question, the answer is critical.
Thanks for the comment, Ross.
AccuRev has a feature called Stream Browser History that does a lot of what you are asking for. To use it, go to the Tools | Preferences menus, select the Stream Browser tab, and make sure that Enable Stream Browser History is checked. Close the preferences dialog, and either restart the GUI, or just click the Refresh icon on the stream view. Thereafter, you will see a control on the top right of the StreamBrowser view that enables you to view the state of the stream hierarchy at any point in time. There are forward/backward arrow controls that will move you back and forth one transaction at a time also.
That said, there are some limitations. If you are viewing any time other than ‘now’ (the latest transaction), the view of the stream hierarchy is static, meaning that the right-click menu normally available on each stream is unavailable. So if, for example, you really need to diff two streams as of 6 months ago, you would need to:
1. View the latest transaction while in Stream Browser History mode (or just turn this feature off via the Preferences dialog described above)
2. Create two time based streams off of the streams in question, setting the time basis to your desired time in the past
3. Perform the diff between these time-based streams via the standard Show Diff By mechanisms in the StreamBrowser.
AccuRev records all of the data required to perform any such calculations – you just need to use streams to access it.
AccuRev looks interesting. TargetProcess (agile project management software) does not integrates with it so far, we support Subversion, Perforce and SS, but likely will add AccuRev integration soon.