Being agile is different for a 100-person project than for a 10-person project. The agile 100-person project will use a heavier methodology than the agile 10-person project. This matches the methodology design principles in the Chapter 4.
Of course, also in keeping with the methodology design principles, it might be possible to drop 90 people from the 100-person project, keep the 10 best people, and then run an agile 10-person project that delivers the same system in the same time frame.
The point is that we agree that methodologies do not come in ones or twos, but in dozens, each tuned to the situation and project at hand, and each agile. This thought is not captured in the Manifesto.
Some of the people in the room recommend agile methodologies primarily for high-flux situations. My experience is that rude surprises pop up on even supposedly stable projects. I am still waiting to see an occasion when the agile value set
The group of 17 quickly agreed on those value choices. Developing the next level of statements proved more than we could settle on in the time left in the meeting. Those in this section are the current working set.
These statements should evolve as we learn people's perceptions of our words, and as we come up with more accurate words ourselves. I shall be surprised if this particular version isn't out of date shortly after the book is published. For the latest version, check www.AgileAlliance.org.
We expect not to agree on the next level of recommendations, which relate to project tactis: how much architecture to develop at what times, what tools to use or avoid, and so on. We each still have our own experiences, fears, wishes and philosophies, which color our practices and recommendations. We shall differ at some specificity of recommendation.
These are the sentences we agreed on, and my commentary on each.
1. Our highest priority is to satisfy the customer through early and frequent delivery of valuable software.
We are interested in delivering software that is fit for purpose. Oddly, some of the companies I visit don't seem to value actually delivering software. Agile development is focused on delivering.
Delivering early allows for quick wins and early feedback about the requirements, the team, the process, as we have seen throughout this book.
Delivering frequently allows for continued wins for the team, rapid feedback, and mid-project changes in project direction and priorities.
The duration used for deliveries needs to be negotiated on a project-by-project basis, because delivering updates on a daily or weekly basis can cause more disturbance to the users than it is is not appropriate the Values worth. When users can't absorb changes to the system as often as every three months, then the project team needs to arrange some other way to get that feedback and to make sure their process works all the way through test and integration.
Statement emphasizes delivering those items that have greatest value to the customers. With consumer mood changes, intensive competition, and stock market swings, it is nearly impossible to guarantee a revenue stream for a project that takes a year or longer to deliver.
This statement indicates that value will be delivered early, so that in case the sponsors lose funding, they will not be left with a pile of promissory notes, but with working software that delivers something of value to the buyers.
2. Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale.
This half to the "early and frequent" delivery specifies the lengths of the work cycles. I have encountered the occasional project that can run incremental development with four-month cycles, but most use one- to three-month cycles. Using shorter cycles is rare, because the users usually can't take in more frequent changes than that.
On project Winifred (Cockburn 1998), a fixed-price contract involving 50 people over 18 months, we fixed our cycles for deliveries to users at three months. Knowing that this was really too long to wait for feedback, we made sure that some expert users came and had two chances to review running code inside each cycle. These two user viewings were scheduled flexibly, usually around the 6-week and 8-week marks.
If the users can accept changes every month, and the development team can match the ongoing requests for changes, then the shorter feedback cycle is better.
3. Working software is the primary measure of progress.
This is the third reference to working software. This principle puts it firmly: rely on the honesty that comes with running code rather than on promissory notes in the form of plans and documents. You are welcome to use other measures of progress as well, but working code is the one to bank on.
Agile methodologies place a premium on getting something up and running early, and evolving it over time. Not all projects are equally amenable to tiny evolutionary steps. Deciding how to break up the giant architecture on a large project into smaller pieces that can be built and tested incrementally, does take some work. It can be done, however, and is worth the effort.
Stephen Mellor is careful to point out that in model-driven development, two pieces of working code must be demonstrated. One is the executable model, which is evaluated for fitness to the user needs. The other piece of working code to be demonstrated is the mapping algorithm that generates the final code. This one is more easily overlooked. A number of projects created a gorgeous executable model, and then couldn't get the code-generation algorithm to work properly in time.
4. Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage.
Agile processes can take on late-changing requirements exactly because of early and frequent delivery of running software, use of iterative and timeboxing techniques, continual attention to architecture, and willingness to update the design.
If your company can deliver quickly and respond to late-breaking information, and your competitor's company can't, then your company can out-maneuver your competitors on the software front. This often translates to a major difference in the marketplace.
All of the agile methodologies have some mechanism to incorporate late-breaking changes in requirements, as already discussed. The details differ by methodology.
5. Business people and developers work together daily throughout the project.
The industry is littered with projects whose sponsors did not take the time to make sure they got what they needed. Frakes and Fox reported a study showing a strong correlation between links to users and project success or failure (Frakes 1995).
The best links are through on-site business expertise and daily discussions, which is what the statement calls for. The word "daily" refers to the sweet spot, where discussions are ongoing and on-demand. Daily discussions are not practical on most projects, which means that the project is not sitting at the sweet spot. The statement indicates that the longer the time to get information to and from the developers, the more damage to the project.
6. Build projects around motivated individuals.
Give them the environment and support they need, and trust them to get the job done.
We would rather see motivated, skilled people communicating well, and no process at all, than a well-defined process and unmotivated individuals. Dee Hock's story about the early VISA system gives an extreme example of this.
Individuals make projects work. Their motivation relates to the pride-in-work, amicability and community on the project.
I first encountered the above statement in a project interview with Dave A. Thomas, then Presdent of the very successful company, Object Technology International. He said, "We hire good people, give them the tools and training to get their work done, and get out of their way." I keep finding evidence supporting his recommendation,.
7. The most efficient and effective method of conveying information to and within a development team is face-to-face conversation.
This falls directly out of Chapters 3 and 4 in this book. I won't repeat the discussion and caveats here. Review those chapters if you are just dipping into the book here.
8. The best architectures, requirements, and designs emerge from self-organizing teams.
We had some discussion around the choice of words in this principle. How self-organizing do we intend: completely self-organizing, or merely allowing good ideas to come from anyone on the project? Do we mean emerge mysteriously, emerge in small steps over time, or emerge as a logical consequence of the human-centric rules the team uses?
I prefer the middle of the three choices. Jim prefers the latter of the three. None of us intend the first of the three, which comes from a misunderstanding of the word emergent as "lucky." Our common point is recognizing that the details of system design surprise even the most experienced designers.
We insist that the architecture be allowed to adjust over time, just as the requirements and process are. An architecture locked down too hard, too early, will not be able to adjust to the inevitable surprises that surface during implementation and with changing requirements. An architecture that grows in steps can follow the changing knowledge of the team and the changing wishes of the user community.
9. Continuous attention to technical excellence and good design enhances agility.
A tidy, well-encapsulated design is easier to change, and that means greater agility for the project. Therefore, to remain agile, the designer shave to produce good designs to begin with - and -also have to review and improve their design regularly, to deal with the better understanding of their design that comes with time and clean up from when they cut corners to meet a short-term goal. Managing Technical Debt
Ward Cunningham sometimes compares cleaning up the design with paying off debts. Going further, he discusses managing the technical debt on the project.
Making hasty additions to the system corresponds to borrowing against the future, taking on debt. Cleaning up the design corresponds to paying off the debt.
Sometimes, he points out, it is appropriate to take on deb and make hasty changes, in order to take advantage of an opportunity. Just as debt accumulates interest and grows over time, though, so does the cost to the project of not cleaning up those hasty design changes.
Cut corners in the design, he suggests, when you are willing to take on the debt, and clean up the design to pay off the debt before the interest grows too high.
Given the deep experience present in the room, I found it interesting to see this attention to design quality at the same time as the attention to short time scales, light documentation, and people.
The conflicting forces are resolved by designing as well as the knowledge at hand permits, but designing incrementally.