the kanban method

What is the Kanban method?

Kanban - Chapter 2

Introduction:Trip to Imperial Palace

Gardens

• every visitor gets a card• on departure the cards are handed back• no money transfer is involved

Perception:Imperial Palace Gardens uses a

Kanban System• restrict the quantity of visitors in the

gardens• card available? → hand out a card• no card available? → visitors have to

wait

think beyond manufacturing with respect to kanban systems

What is a Kanban System?

Setup

• a number of cards == agreed capacity of the system

each card acts as a signaling mechanism

Rules for process flow

• only if a card is available a new piece of work may be started

• if there is no free card work must be queued until a card becomes available

Rules for process flow

• each piece of work has a card attached• card remains attached while the work

travels through the system• on work complete detach card and recycle

card

Kanban is a pull system

• work is pulled into the system when there is free capacity

• work is not pushed into the system on demand

• if the number of signal cards has been set appropriately, the system cannot be overloaded

In the imperial gardens example

• the gardens are the system• the visitors are the Work In Progress (WIP)• the admission cards are the signal cards• the capacity is limited by the signal cards

in circulation

Limiting the visitor count helps

• maintain the gardens in good condition• avoid damage caused by too much foot

traffic and overcrowding

Benefits

• simple• cheap• easily implemented

Kanban applied in software

development

Use a virtual Kanban system to limit WIP

• there are cards used in most implementations

• those cards are not the signal cards to pull more work

• they represent the work items• there are no physical cards therefore it’s

called virtual

The signal to pull new work is derived

• check the current WIP• check the agreed capacity• subtract WIP from capacity• if the result is not null and positive

• pull in new work

Card walls are commonly used

• using a card wall doesn’t make the system kanban

• it’s a means to track the flow of work inside a system

• if there is no WIP limit and no signaling then the system is not a Kanban System

Main purpose of card walls

• visually observe WIP• allow self-organization• allow to self-assign tasks• navigate work through the system• drop the need of dedicated management

Why use a Kanban system?

• achieve a sustainable pace of development• maintain good work-life-balance for

everybody involved• „Kanban is a catalyst for the emergence of

a more agile organization through evolutionary cultural change“ (David J. Anderson)

Three basic principles

1. Start where you are right now.

2. Find consensus that everybody wants incremental and evolutionary change.

3. Honor the process in place as well as existing roles, responsibilities and job titles.

State of the art1. visualize workflow

2. limit WIP

3. measure and manage flow

4. make process policies explicit

5. use models to recognize improvement opportunities

What Kanban is not

• a software development lifecycle methodology

• an approach to project management

Conclusion

Kanban as a permission giver:• try Kanban• modify the underlying process• be different