Kanban & Lean

Kanban and Lean provide complementary approaches to optimizing workflow and eliminating waste. For the PMP exam, understanding these methods helps answer questions about flow-based project management and continuous improvement.

Kanban Origins

Kanban originated in the Toyota Production System (TPS), developed by Taiichi Ohno in the 1940s-1960s. The word "kanban" means "visual signal" or "card" in Japanese. Toyota used physical cards to signal when more parts were needed, creating a "pull system" that reduced inventory and improved efficiency.

David J. Anderson later adapted these principles for knowledge work, creating the Kanban Method for software development and project management.

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The Four Core Kanban Principles

Additional Foundation Principles

• Start with what you know: Begin with current processes
• Pursue incremental change: Make small, evolutionary improvements
• Respect the current process: Don't disrupt what's working
• Encourage leadership at all levels: Anyone can suggest improvements

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The Kanban Board

A Kanban board visualizes work flowing through stages:

|  BACKLOG  |  TO DO  |  IN PROGRESS  |  REVIEW  |   DONE   |
|           |         |    WIP: 3     |  WIP: 2  |          |
|-----------|---------|---------------|----------|----------|
|  Item 8   | Item 6  |    Item 3     |  Item 2  |  Item 1  |
|  Item 9   | Item 7  |    Item 4     |          |          |
|  Item 10  |         |    Item 5     |          |          |

Each column represents a workflow state. Cards move from left to right as work progresses.

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Work-in-Progress (WIP) Limits

WIP limits control how many work items can exist in each column simultaneously. They are the cornerstone of Kanban's effectiveness.

Why WIP Limits Matter

Little's Law

Little's Law provides the mathematical foundation for WIP limits:

Lead Time = WIP / Throughput

This means:

• Reducing WIP reduces lead time (when throughput is constant)
• WIP limits create a pull system rather than a push system
• The goal is to optimize the whole system, not local efficiency

Setting WIP Limits

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Flow Optimization

Kanban focuses on optimizing flow -- the smooth, predictable movement of work through the system.

Key Flow Metrics

Bottleneck Identification

When work piles up in a column (exceeding WIP limits), it signals a bottleneck. The team should:

1. Stop starting new work
2. Swarm to clear the bottleneck
3. Analyze root cause
4. Implement systemic improvements

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Lean Principles

Lean is the broader philosophy that Kanban draws from. Lean focuses on maximizing value while minimizing waste.

The Seven Wastes (Muda)

Three Types of Waste

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Value Stream Mapping

Value Stream Mapping visualizes the entire flow of work from customer request to delivery, identifying:

• Value-adding steps: Work the customer pays for
• Non-value-adding steps: Waste to eliminate
• Wait times: Delays between steps
• Cycle times: Duration of each step

Value Stream Map Example

Request -> [Wait 2d] -> Design -> [Wait 1d] -> Develop -> [Wait 3d] -> Test -> Deploy
              (3h)                    (8h)                  (4h)        (1h)

Total Lead Time: 6+ days
Value-Adding Time: 16 hours
Efficiency: ~33%

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Kanban vs. Scrum

When to Use Kanban

• Operations and support work
• Continuous delivery environments
• Work with highly variable priorities
• Teams maintaining existing products
• When sprints feel artificial

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PMP Exam Tips

For the PMP exam, recognize Kanban scenarios by these keywords:

• Visualize work on a board
• Limit work-in-progress
• Continuous flow (no fixed sprints)
• Pull system vs. push system
• Optimize flow, not utilization

When a question describes overloaded columns or slow flow, recommend:

• Enforcing or lowering WIP limits
• Focus on finishing before starting
• Identify and address bottlenecks

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Key Takeaways

• Kanban visualizes work and limits WIP to optimize flow
• Little's Law: Lead Time = WIP / Throughput
• WIP limits can improve throughput by 40% and reduce lead time by 60%
• Lean eliminates waste (muda, muri, mura)
• Value stream mapping identifies improvement opportunities
• Kanban enables continuous delivery without prescribed iterations