Kanban - Introduction

2014-10-17, Tomas Rybing, Aptilo Networks

”Kanban is a method for managing knowledge work with an emphasis on just-in-time delivery while not overloading the team members. In this approach, the process, from

definition of a task to its delivery to the customer, is displayed for participants to see and team members pull work from a queue”, from Wikipedia - ”Kanban (development)”

Agenda• Background - Lean

• Kanban and theories behind

• Context switching

• Little’s law

• Theory of constraints

• Feedback loops

• Kanban - Principles

• Visualize

• Limit WIP

• Manage flow

• Other - Daily stand-up, planning, estimation, retrospectives and priority pyramid

• Summary

Kanban is Japanese and means ”sign” or ”index card”, this picture taken from the book ”The Toyota way”

Background - Lean• Lean principles originates from Toyota Production

System (TPS)

• Started in Japan after WW2, huge investments for ”moving assembly line” wasn’t possible

• Instead supermarkets were studied, they filled their stock only when it was close to become empty

• JIT (Just In Time) was born. Don’t build stock it will hide problems in your process

• Kaizen - ”Continuous improvement”

• Muda - ”Waste”

What is Lean (a leantroduction☺)?

Flow efficiency

Resource efficiency

The e

fficien

cy

matrix

© Niklas Modig and Per Åhlström from ”Detta är lean”

What is Lean?

Flow efficiency

Resource efficiency

What is Lean?

Flow efficiency

Resource efficiency

What is Lean?

Flow efficiency

Resource efficiency

What is Lean?

Flow efficiency

Resource efficiency

What is Lean?

Flow efficiency

Resource efficiency

This is Lean

Kanban and theories behind• ”Tool for improving what you do every day” - Hammarberg

• Lightweight - Easy to start with (is evolutionary)

• Blend in with your current development process

• Theories behind

• Context switching

• Little’s law

• Theory of constraints

• Feedback loops

Context switching (1 of 2)• Public Enemy No.1 in creative

work

• ”One thing at the time” is most effective

• One project - 100% work time

• Two projects - 10% per project spent in context switching

• Three projects - ”Forget about it” (Johnny Depp from the movie ”Donnie Brasco”)

© Gerald Weinberg’s book ”Quality Software Management: Systems Thinking”

Context switching (2 of 2)• Report time on ticket

• Project One

• Project Two

• Update Delivery Tracker (Sharepoint)

• Project One

• Project Two

• Update Scorecard (Sharepoint)

• Project One

• Project Two

• Project One

• Report time on ticket

• Update Delivery Tracker (Sharepoint)

• Update Scorecard (Sharepoint)

• Project Two

• Report time on ticket

• Update Delivery Tracker (Sharepoint)

• Update Scorecard (Sharepoint)

A B

Little’s law• Work in Process = Number of items

you work on at the same time

• Throughput = Average time to complete each item (ex. 12 items/month)

• Cycle time (or lead time) = Time through the process for each item

• Cycle time (1) = 12 / 12 = 1 month

• Cycle time (2) = 6 / 12 = 0,5 month

• Reduce WIP to speed up work flow

Work in process Cycle time =

Throughput http://en.wikipedia.org/wiki/Little's_law

Theory of constraints• Any manageable system is being limited

in achieving more of its goals by a very small number of constraints (bottlenecks).

• Or to simplify, ”a chain is not stronger than it’s weakest link”

• Five focusing steps to address constraints (not covered here)

• Short term - Maximize utilization of the ”bottleneck”

• Long term - Invest to ”remove” bottleneck

http://en.wikipedia.org/wiki/Theory_of_constraints

Feedback loops• As short feedback loop as

possible!

• Feedback is the creator of knowledge

• Delay causes extra work - vicious circle Vicious circle

Slow feedback

More work

DelayHigh WIP

© Marcus Hammarberg www.marcusoft.net

Kanban - Principles

• Visualize

• Limit WIP

• Manage flow

Visualize• Kanban board - Whiteboard or

other empty wall space

• Columns represents steps in work process

• Work tasks represented by cards or stickies

• How to find columns? Dry-run a few tasks through your work process

• Avatars

Team Kanban board

Personal Kanban boards @ Aptilo

Limit WIP• WIP (Work In Process) means

all the work that you have going on right now

• Limit WIP to secure flow

• Set WIP limit - Pick a number and try it out (then learn and adjust)

• WIP per column or team/whole board

• Stop starting, start finishing!© Marcus Hammarberg www.marcusoft.net

Manage flow• Flow is when each part of the work

moves from one value adding step to another without any waiting times or delays (cornerstone in TPS)

• Limit WIP

• Remove blockers (swarming)

• Continuous improvement - real purpose of Kanban

• Retrospectives

• Root-cause analysis

• Toyota Kata© Håkan Forss http://hakanforss.wordpress.com

Other• Daily stand-up

• Focus on tasks, not individuals

• Walk the board from right to left, to ”pull tasks”

• Planning

• Just-in-time planning

• Threshold triggered planning

• Estimation

• Planning poker

• T-shirt sizes

• Retrospectives

• Periodically - For continuous improvements to work process

Daily standup meeting

Priority pyramid (1 of 2)• ”Human beings want three things

in life: sex, money and effective prioritization” - Jim Benson

• Why keep a long list and decide if a task shall be on position 36 or 37, the only things you care about is your next upcoming tasks

• Good sequencing decisions as late as possible for the lowest incremental cost

• Visualization!Enhancement of ”Priority filter” by Corey Ladas

http://leansoftwareengineering.com/2008/08/19/priority-filter/

Priority pyramid (2 of 2)•☺

Kanban - Who else is using?

http://www.infoq.com/articles/kanban-operations-spotify

”Lean from the Trenches” book by Henrik Kniberghttp://www.infoq.com/articles/kanban-siemens-health-services

Summary• Theories behind

• Context switching - Avoid if possible

• Little’s law - Cycle time (or lead time) = WIP / Throughput

• Theory of constraints - To find and handle bottlenecks

• Feedback loops - As short as possible

• Principles

• Visualize - Kanban board

• Limit WIP - For flow efficiency

• Manage flow - Continuous improvements of the work process

© Marcus Hammarberg www.marcusoft.net