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Karl Scotland – Using Agile to Deliver Value
Karl Scotland – Using Agile to Deliver Value
Jul 21st
Mark Stringer gave me some good feedback recently, that I clearly hadn’t described what I meant be Cadence at the recent miniSPA conference. In order to try and correct that, I thought I’d try and clarify with a blog post that it not simply variable length iterations.
The purpose of a cadence is to establish a reliable and dependable capability which demonstrates a predictable capacity. Cadence gives some confidence in the upcoming work when we are triggering rather than scheduling work.
Time-boxing is one specialised form of cadence. It’s like a metronome, giving a single tick. All the main process events are based around this single tick, as shown below where the dotted vertical lines represent the Sprint boundaries. In this example, the unit of work is a User Story, and User Stories should be small enough to be scheduled into a Sprint, and subsequently completed in the same Sprint. Stories in Progress are limited to two, as a good Scrum team might, but Stories don’t always fit exactly into a Sprint. Note also, that while releases can happen each Sprint, User Stories are only potentially shippable product increments.
Kanban on the other hand has a cadence which is more like a drummer. The rhythm is more complex than the single tick of a metronome, and can be more varied, as shown below. In this example, the unit of work is a Minimal Marketable Feature, which while needing to be as small as possible, is not constrained be being required to fit into a schedule. Instead, an MMF is able to flow over a number of process events while it delivers some releasable value. Planning, reviewing, retrospection and releasing all still happen regularly, but they are de-coupled. They can happen independently, at differing rates, which may provide more freedom in creating a natural process which enables the team.
A cadence is usually ‘harmonic’, in that there is a neat overlap between the different rhythms, as in this example. However, it does not have to be. A look at some definitions of cadence can show why. These are some favourites I picked off dictionary.com
Thus cadence is what gives a team a feeling of demarcation, progression, resolution or flow. A pattern which allows the team to know what they are doing and when it will be done. For very small, or mature teams, this cadence could by complex, arrhythmic or syncopated. However, it is enough to allow a team to make reliable commitments because recognising their cadence allows them to understand their capability or capacity.
May 13th
At the SPA conference recently, Joseph Pelrine talked about “Flow: The Psychology of Optimal Experience” by Mihalyi Czikszentmihalyi. The ideas behind this struck a chord with me as a way of describing something I originally said when discussing whether kanban is only suitable for mature teams. That is that rather than focusing on being Agile which may (and should) lead to being successful, Kanban focuses on becoming successful, which may lead to being Agile.
Mihalyi Czikszentmihalyi describes the state of Flow as having a balance between ability, and the skills required for a piece of work. If some work requires more skill than a person has ability, then they are in a state of Anxiety. If a person has more ability than the skills required for a some work then they are in a state of Boredom. Applying this to Process Improvement, we want to move teams up the Flow Zone so that skills required and ability increase equally.
Increasing Skills and Ability equally at the same time is unlikely, so in practice there are two routes to move up the Flow Zone. The first is what I am dubbing “Anxiety Driven Process Improvement”. Move a team into a state of Anxiety such that they need to improve their skills to cope. I assert that this is the approach that makes time-box based method so effective. Time-boxing forces teams into a place where they need to improve their skills in order to deliver working software every few weeks. Many teams push back, and a common approach to this is to make the time-box shorter to emphasis the point! The other route is to do “Boredom Driven Process Improvement”. Highlight to the teams where they need to improve their ability, and allow and support them in doing so such that they are able to taken on work requiring more skill. I further assert that this is the approach that kanban systems take. Visualising queues and work in progress in order expose the bottleneck where the ability needs improving.
This might sound like I am suggesting the time-boxing and kanban are mutually exclusive approaches. That isn’t the case – I have already said that! Instead, I just find it an interesting angle to look at a different dynamic between two approaches.
May 9th
I had a brief exchange of tweets with Ron Jeffries, Keith Braithwaite and James Shore after the Miami Lean and Kanban Conference ended regarded Kanban and its compatibility with XP and time-boxes. Unfortunately I wasn’t able to follow up immediately, due to an urgent (and eventful) trip to South Beach
Rather than try and follow up late on twitter, I’ve decided to post my thoughts here to try and clarify my ideas.
The discussion started following a tweet about Kanban being easier to introduce than Scrum. This seemed to be a common theme at the conference, with several experience reports confirming what I have already written about whether Kanban is only suitable for mature teams. This led to the question of how much change (or not) a Kanban approach requires, which is where I jumped in.
A kanban approach introduces tools to visualise and measure queues and work in progress. While this is a change in process measurement, it doesn’t change the process itself. However, having highlighted the existence of queues and work in progress, it becomes easier for the process to be changed to specifically fix the issues highlighted. Thus a Kanban system sets a team up to begin continuous improvement. Time-boxing, used by XP and Scrum, is one way to manage queues and WIP, which is why they can be such effective processes, and why shorter time-boxes are becoming more popular. There are other ways of managing queues and work in progress, however, and thus Kanban is agnostic to time-boxing. This does not mean that XP is Kanban system however, because XP implicitly, rather than explicitly, manage the queues and work in progress.
Further benefits of time-boxing are the focus that they give, particularly given the finite or limited resources (i.e. people) within a team. Time-boxes give this focus not only by limiting the work-in progress, but also by setting the end of time-box as an SLA for when the work will be completed. Again, Kanban doesn’t lose these benefits, but provides for alternate means to limit work in progress and set SLAs.
To summarise, I believe that a Kanban approach is compatible with XP and Scrum in that it has a focus on managing queues and limiting work in progress, but also introduces alternate ways to achieve these goals which can be used alongside the XP and Scrum tools such as User Stories, TDD and Retrospectives.