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Scaling Scrum
The Full Development Picture
Construction is only one part of the overall software development
lifecycle. Figure 2 presents an overview diagram of the Agile lifecycle
which encompasses the ideas presented in Figure 1 and extends them to
address the full range of software development issues. This lifecycle
explicitly includes the concept of phases because the activities that
you perform do in fact change throughout the span of a project. I‘ve
adopted the normalized terminology described in the sidebar plus other
common agile phase terminology—many agile teams refer to project
initiation effort as "iteration 0" and transition as the release phase.
In the Eclipse Way, the Agile process followed by the Eclipse
development team, they use the terms "warm up" and "end game"
respectively. In Agile and Iterative Development
(Addison Wesley, 2004), Craig Larman uses the terms "pre-game" and
"release" for these phases. The Open Unified Process (OpenUP) uses the
terms Inception and Transition respectively. Sadly, many people
consider the concept of phases to be antithetical to agility, yet in
practice they seem to be a fundamental lifecycle concept.
Figure 2 encompasses several critical activities to scale Scrum to meet your real-world development needs:
- You need to do some initial requirements and
architecture envisioning at the beginning of the project to address
basic questions around scope, cost, schedule, and technical strategy.
Few projects are funded without acceptable answers to these issues.
- To
ensure the quality of your work, you should have an independent test
team that works in parallel to the development team. This team reports
change stories back to the team who then treats them exactly like a
requirement—they‘re estimated, prioritized, and put on the work item
stack (see "Scaling Test-Driven Development", www./architect/205207998).
- The
"work item stack" contains all of the potential items of work that a
team may need to address, not just stakeholder requirements. For
example, you need to set up people‘s workstations, fix defects, people
attend training, they take vacations, they review the work of other
teams, and so on. These are important activities that must be planned
for accordingly.
- Iterations can be any length, not just 30
days, and an individual team needs to determine which is best for them.
As Dr. Dobb‘s 2007 Agile Adoption Survey (www./architect/200001986) found, the most popular iteration length is two weeks.
- Effective
agile teams prove their architecture with code early in the project
(this is the Elaboration part of Elaboration and Construction).
Although purists claim that you should prioritize based solely on
business concerns, the reality is that it behooves you to address
technically risky requirements early in the lifecycle. Luckily,
business value and technical risk often go hand-in-hand, so you rarely
need to "game" your work item stack much to accommodate this strategy.
- The
Transition phase provides time to successfully release software into
production. This effort includes training people, finalizing testing,
finalizing documentation, pilot/beta testing, and deploying the system;
see "The Agile End Game" (www./architect/198800565) for more detail.
- Enhancement
requests and defect reports are identified once the system is in
production and treated as new work items that must be prioritized.
[Click image to view at full size]
Figure 2: The Agile Software Development Lifecycle. The full
development lifecycle must address project initiation, construction,
and deployment.
Since the late 1990s, I‘ve written that effective software
development is serial in the large, iterative in the small, delivering
incremental releases over time. Over the past few years the rhetoric
around agile software development has unfortunately drowned out the
"serial in the large" part of the message, forcing many people to
rediscover proven techniques and strategies. If the lifecycle of Figure
2 makes sense to you, and you‘d like to extend Scrum to address these
issues, I suspect that you‘ll find that the OpenUP, downloadable free
of charge at www./epf, will be of interest to you.
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