Agile software development practices are based on a set of values and principles described in the Agile Manifesto. As change agents for Agile transformation, we rely on these to help get the message across. There is another layer below principles, a set of scientific models that can help explain why the principleswork and strengthen the Agile message for some audiences. These are described in this presentation.
4. Systems are greater than the sum of their parts.
System properties and behaviors emerge from the
combination of its constituent parts
Reductionism is not
sufficient. Our systems
are dynamic and
driven by nonlinear
effects that are not
easily understood.
5. Helpful Theoretical Models
Queuing Theory – Erlang 1910
Lean Thinking – Deming 1940
System Dynamics – Forrester 1950
Automata Theory – 1940 Ulam and von Neumann
Network Theory - 1970
Complexity Theory - 1970
Learning Organization – 1990 Senge
A model is a simplification of reality
intended to promote understanding.
6. System Dynamics
A system is an entity which maintains its
existence through the mutual interaction of its
parts.
- Gene Bellinger
Orderly processes in creating human judgment
and intuition lead people to wrong decisions
when faced with complex and highly interacting
systems.
- Jay Forrester
9. Feedback Delay
Time
DesiredState
Long delay causes
wider swings
Short delay
converges sooner
Agile/Lean achieve smoother flow
and reduced risk by shortening
the delay time for feedback
11. Lean Thinking
95% of variation in the performance of a system
(organization) is caused by the system itself and
only 5% is caused by the people.
- W. Edwards Demming
Misconception easily turns into common sense.
- Taiichi Ohno
12. Push & Pull Systems
Push systems overwhelm capacity, creating
turbulence, rework, waste and delay
Pull systems have a steady flow that
provides predictability
♫
Push
13. Push Pull
Make a plan Have a queue of work and a goal
Track % completion of plan Measure throughput and work done
Buffer plan for contingencies Small, frequent tasks to manage
variety
Plan decides what to do next People decide what to do next
Long feedback delay Continuous short feedback loops
Demand exceeds capacity Demand limited to capacity
Fixed scope and time Fixed WIP
Forecast based on estimates Forecast based on data
18. Goodhart’s Law
The moment a measure
becomes a target,
it ceases to be useful as
a measure.
Story Points/Sprint
19. Complexity Theory
Complicated
Complex
Click pictures to view examples.
• Many different
parts.
• Can take it apart
and reassemble it.
• If one part fails, it
all fails.
• Many similar parts acting
independently within social rules.
• Aggregate behavior cannot be
predicted from individual part
behaviors.
• Still “works” if a part is removed.
21. Sense
Input
What our senses tell us
Probe
How we use our senses to
get new information
Mental Models
What sense we make of new
information
Actions, Experiments
What makes sense to do next
24. Working as a
Team
Organizations where people continually expand
their capacity to create the results they truly
desire, where new and expansive patterns of
thinking are nurtured, where collective
aspiration is set free and where people are
continually learning how to learn together.
- Peter Senge The Fifth Discipline, 1990
25. Urgent Not Urgent
Important
I
• Crises
• Pressing
Problems
• Deadline Driven
Projects,
Meetings, etc.
II
• Preparations
• Learning
• Kaizen Events
• Relationship Building
• True Recreation
NotImportant
III
• Interruptions
• Some phone calls
• Some email
• Someone else’s
emergency
IV
• Trivia
• Busy work
• Time wasters
• “Escape” activities
When do we get time to improve?
If we don’t spend any time
sharpening the saw, we will
have to work harder and
harder to get the same
results.
- Steven Covey, The 7 Habits of
Highly Effective People, 2004
By intentionally creating
downtime, or ‘slack’,
management will find a
much-needed opportunity to
build a ‘capacity to change’
into an otherwise strained
enterprise that will help
companies respond more
successfully to constantly
evolving conditions.
- Tom DeMarco, Slack, 2002
26. Learning Levels
Single Loop: tweak the parameters
Double Loop: experiment with the process
Triple Loop: learn how to learn
27. Retrospectives
Communities of Practice
Book Club
Brown Bag Seminars
Shadowing
Story Telling
Knowledge Management
Brainstorming
Skills Exchange
Team Learning Tools
28. References
Books:
• Thinking in Systems : A Primer – Meadows
• The Fifth Discipline and its Fieldbook – Senge
• Business Dynamics - Sterman
• The Principles of Product Development Flow: Reinertsen
• The Systems Bible – Gall
• 10 Steps to a Learning Organization – Kline and Saunders
• Learning in Action – Garvin
• Systems Thinking Playbook – Sweeny and Meadows
Websites
- www.beyondconnectingthedots.com/ - Bellinger
- www.cognitive-edge.com – Snowden
- www.systemdynamics.org
29. Presenter
Roger Brown
• Agile Coach
• Scrum Alliance
• M.S. System Dynamics, Dartmouth College 1977
• Contact
Email: roger@agilecrossing.com
Twitter: rwbrown
Blog: www.agileCoachJournal.com
LinkedIn: http://www.linkedin.com/in/rogerwbrown