We’re All Wrong About Little’s Law

Agile Uprising Podcast Episode Artwork: We're all wrong about Little's LawIn this podcast episode, co-hosts Andy Cleff and Troy Lightfoot discuss the misconceptions about Little’s law, the differences between what Dr. Little created and what is often taught, and how Little’s Law can be useful in practice today by understanding the underlying assumptions.

(Follow-along images for the podcast are below.)

Four Key Measures and Feedback Loops for All Flight Levels

Little's Law: Lead Time equals WIP divided by Throughput
Want to impact throughput or lead time? What’s the easiest variable to control?!

Meaningful metrics, measures, and feedback loops for portfolio, program, and team-level work items:

  • WIP: The number of work items started but not finished. (Leading indicator)
  • Throughput: The number of work items finished per unit of time. Note the measurement of throughput is the exact count of work items. (Lagging indicator)
  • Work Item Age: The amount of elapsed time between when a work item started and the current time. (Leading indicator)
  • Cycle Time: The amount of elapsed time between when a work item started and when a work item finished. (Lagging indicator)

Bonus Measure

  • Team Health: Level of employee satisfaction in their work, their willingness to go the extra mile, their passion for the purpose of their jobs, and their commitment to the organization (Leading indicator)

Getting Started

Table of metrics and use to inspect and adapt scrum events
From https://prokanban.org/scrum-flow-metrics/
  • Visualize your workflow for work items at all flight levels (Definition of Work, DoW for Initiative, Epics, Feature, Story, etc.)
  • Establish the starting point for work items with a Definition of Ready (DoR)
  • Establish the finishing point for work items with a Definition of Done (DoD)
  • Track work items’ start and finish dates
  • Inspect and adapt – Queues, batch sizes, WIP limits, flow efficiency, bottlenecks, dependencies… during daily scrum, sprint review, retrospectives

The end result: a self-optimizing system of continuous, permanent improvement (kaizen) in which value throughput is always increasing.

Podcast Follow Along Images

Aging Work In Progress (WIP)
Aging Work In Progress (WIP)
Cycle Time with Backlog State
Cycle Time with Backlog State
Cycle Time Scatter Plot
Cycle Time Scatter Plot

Take a Deeper Dive

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