from scrum to kanban

From Scrum to Kanban

Neil Johnson

ScrumKanbanLessons Learned

“The only thing that really matters is the quality of the team. Everything else is an optimisation.“

ScrumKanban Lessons Learned

Working environment

• Software as a Service• Services sold on their reliability and availability• Industry is still very young, continual innovation

is essential• Teams are cross functional• All members responsible for design,

implementation, deployment and maintenance• Easy access to Product Development/Business

Before Kanban we used Scrum (kinda)

• Scrum practices• Time boxed iterations of 2 weeks• White board and post its to track status• Daily stand ups• Fortnightly retrospectives

• Not Scrum• Deploy multiple times an iteration• No formal product owner• No end of iteration demo

What we liked about Scrum

• A sense of rhythm and points to reflect on our working practices

• Better visibility over tasks that were dragging on

• A highly visible feedback loop to help improve our estimations

Scrum was great but we had two problems with it….

The iteration deadline felt artificial

• No expectation from business of a post iteration demo

• High dependence on outside parties• Frequently over/undershoot due to external

dependencies• Time box limited choice of tasks in case of

undershoot

Not flexible enough mid iteration

• A 2 weeks iteration promises, on average, a 3 week delay

• The team is responsible for 2nd line support, operations and maintenance

• We can assign a maintainer role to shield the team from day to day requests, though this is not always sufficient

• Need a process that actively embraces the notion unplanned work

ScrumKanban Lessons Learned

Scrum vs Kanban comparison

• In common:-• Both are Lean and Agile• Both use pull scheduling• Both use transparency to drive process

improvement• Both focus on delivering working software as soon

as possible

Scrum vs Kanban comparison

• Differences• Kanban less prescriptive than Scrum• Kanban does not prescribe fixed iterations• In Kanban Lead Time is the principle metric, in

Scrum it is velocity• Kanban limits Work in Progress directly, Scrum

does this indirectly through sprint planning

Why Kanban?

• Retain our discipline and structure• Limit work in progress rather than work per

time• Improve responsiveness, through reduction in

Lead Time• Can accommodate unexpected work without

modifying the system• Always able to work on the next most

important or risky task

Kanban fundamentals

• Visualise the workflow• Split the work down into small pieces• Represent each work item on a post it and put on the board• Use named columns to express where the work item is in the

workflow• Limit Work in Progress

• Assign explicit limits to how many items may be in progress in each workflow state, or set of states

• Measure the lead time (average time to complete one item) • Optimise the process, aiming to make the Lead Time as small

and as predictable as possible

The Board

• Should reflect your real working practices• Placement of the board is crucial• Work in progress limits drive behaviour• Start with loose, achievable limits and expect

to fine tune• Expect the board to change state on a daily

basis

A simple example

A more complicated example

The post its

How to measure lead time and optimise the process?

Cumulative Flow Diagram

Aslak Hellesøy

Lead Time

ScrumKanban Lessons Learned

Lessons Learned

• Benefits• Greater flexibility in our work flow• We no longer feel that we are fighting our process• Better able to embrace and support unexpected

work items• Negatives• Greater discipline is required in ensuring that all

tasks are completed in a timely manner

Lessons Learned

Protect yourself. If you make the team better able to take on ad-hoc tasks, you must track the impact and the load.

I have found the following categorisations to be effective• Planned Product Development work• Planned Engineering work e.g. large scale refactoring• Unplanned Product work e.g. one of reports, small tweaks

to behaviour• Unplanned engineering work e.g. urgent bug fixes

Lessons Learned

• Further observations• Adoption was almost completely painless• Due to day to day interaction, the board takes on a

much more important role than it ever did under scrum

• The team is more confident in deciding what to do next

• Our stand ups have become much more focused• Our retrospectives are no longer coupled to the

period of our iteration.

Is Kanban for you?

You may find value in Kanban over Scrum if:-• The team has support, maintenance or Dev Ops

responsibilities• Time boxed iterations make little sense in your work flow• Your priorities change rapidly• Your organisation is unable to easily support Scrum roles

You may also want to consider hybrid approaches such as ‘Scrumban’

ScrumKanbanLessons Learned

Wrapping up

• Scrum provided us with structure and discipline• Kanban provided a better model for our work

flow by embracing the unexpected and doing away with iterations

• Limiting work in progress makes it easier to consider team level task prioritisation

• Ad-hoc work stacks up, categorise all work items• Kanban is a tool, as is Scrum. Use the right tool

for the job.

And Finally…..

• Contact• neil@fragile.org.uk• http://fragile.org.uk/• @neilisfragile

• References• http://open.bekk.no/2009/11/03/cumulative-flow

-diagrams-with-google-spreadsheets/• http://www.crisp.se/henrik.kniberg/Kanban-vs-Scr

um.pdf