1
Lean
&
kanban
Resource efficiency
Maximize the time a resource adds value
Optimize resource efficiency by focusing on each resource
Cheap product
Optimize flow efficiency by focusing on each flow unit
Maximize the time value is added to the flow unit
Flow efficiency
Quick delivery
T
t
Flow time
Queue length
Nirvana
Flow efficiency =
value adding time for a flow unit / flow time
Alternativ
=
Increased cycle time
Parallelism
Resource efficiency =
the time a resource is used / total time
Flow time = cycle time * flow units in work
Flow time
=
Batching
Alternative
Cycle time is affected by batch size
Time
Cycle time
Littles law
Process
Flow unit
Something that is refined and gets added value
Resource
- Materials
- Humans
- Information
Something that adds value to flow units
Queue in front of a bottleneck
Bottlenecks
Flow efficiency
100%
Ford
More variation
Less variation
Resource efficiency
Toyota
100%
- Resources
- Flow units
- External factors
Scania
Variation
(Kingmans equation)
Done
Testing
WIP limit=1
Lean is a strategy, not a goal
Flow efficiency
WIP limit
Ready for test
WIP limit=3
Lean
@ Kristoffer Richardsson 2012
In progress
WIP limit=2
WIP = Work In Progress
Todo
Nirvana
Resource efficiency
Done
Improve the process by reducing the WIP limit
Testing
Done
WIP limit=1
Ready for test
WIP limit=0
Testing
In progress
WIP limit=1
Kanban board
Todo
Ready for test
Kanban
A tool for optimizing flow
In progress
Measurements
Todo
2. Delivery
1. Order
- Write dates on stores when we start and when done
- Put block-stickers when blocked, start and end dates
- Count nr of stories in each column every day
- Take a photo of the board each day
Kanban tokens
"Pull" system
Kanban tokens
Optimization -> problem
Time