Kanban WIP - Work In Progress Limits Explained
Learn how to set and manage Work In Progress limits to improve team productivity and workflow efficiency
Kanban WIP - Work In Progress Limits Explained
Work In Progress (WIP) limits are one of the most important concepts in Kanban methodology. They help teams focus, identify bottlenecks, and improve overall productivity by preventing work overload.
What are WIP Limits?
WIP limits are the maximum number of work items that can be in progress at any given time in a specific stage of your workflow. Think of them as capacity constraints that prevent your team from taking on too much work at once.
Example WIP limits:
In this example:
- To Do column has a WIP limit of 5
- In Progress column has a WIP limit of 3
- Done column has no limit (∞)
Why WIP Limits Matter
1. Prevent Work Overload
Without WIP limits, teams often take on more work than they can handle, leading to:
- Context switching - Constantly switching between tasks
- Reduced quality - Rushing to complete multiple tasks
- Increased stress - Feeling overwhelmed by too much work
- Missed deadlines - Promising more than can be delivered
2. Improve Focus
WIP limits force teams to focus on completing work rather than starting new work:
- Better concentration on current tasks
- Higher quality output from focused attention
- Faster completion of individual items
- Reduced multitasking and its associated costs
3. Identify Bottlenecks
WIP limits make workflow problems visible:
- Columns that fill up indicate bottlenecks
- Work that gets stuck becomes obvious
- Capacity issues are revealed
- Process improvements become necessary
4. Improve Flow
By limiting work in progress, teams can:
- Move work faster through the system
- Reduce cycle time (time from start to finish)
- Increase throughput (work completed per time period)
- Improve predictability of delivery
How to Set WIP Limits
Step 1: Understand Your Current Capacity
Before setting WIP limits, understand your team’s current capacity:
Questions to ask:
- How many people work in each stage?
- How much work can each person handle?
- What’s the typical complexity of work items?
- How long do items typically stay in each stage?
Step 2: Start Conservative
Begin with conservative WIP limits that are lower than your current capacity:
General guidelines:
- To Do: 1-2 items per team member
- In Progress: 1 item per person working in that stage
- Review: 1-2 items per reviewer
- Done: No limit (∞)
Example for a 4-person team:
- To Do: 6 items
- In Progress: 4 items (1 per person)
- Review: 2 items
- Done: ∞
Step 3: Observe and Adjust
Monitor how the WIP limits work and adjust based on observations:
Signs WIP limits are too low:
- Team members are frequently idle
- Work flows too quickly through some stages
- Team feels underutilized
Signs WIP limits are too high:
- Work piles up in certain columns
- Items stay in columns for too long
- Team feels overwhelmed
Step 4: Refine Over Time
Continuously refine WIP limits based on:
- Team feedback about workload
- Performance metrics like cycle time
- Quality indicators like defect rates
- Team satisfaction and stress levels
Types of WIP Limits
1. Column-Based Limits
Set limits for each column in your workflow:
Example:
Advantages:
- Simple to understand and implement
- Easy to visualize on the board
- Clear capacity constraints
Disadvantages:
- May not account for different work types
- Doesn’t consider individual capacity differences
2. Per-Person Limits
Set limits based on individual team members:
Example:
Advantages:
- Accounts for individual capacity
- More precise control
- Better for teams with different skill levels
Disadvantages:
- More complex to manage
- Requires tracking individual assignments
3. Work Type Limits
Set different limits for different types of work:
Example:
Advantages:
- Balances different work types
- Prevents one type from dominating
- Better resource allocation
Disadvantages:
- More complex to set up
- Requires categorization of work
Common WIP Limit Strategies
1. The “N+1” Rule
Set WIP limits to the number of people working in that stage plus one:
Example:
- 3 developers working in “In Progress”
- WIP limit = 3 + 1 = 4 items
Logic: This ensures everyone has work to do while providing a small buffer for flexibility.
2. The “Half Capacity” Rule
Start with WIP limits at half your current capacity:
Example:
- Team currently has 8 items in progress
- Start with WIP limit of 4 items
- Gradually increase as you optimize
Logic: This forces the team to focus and identify inefficiencies.
3. The “One Per Person” Rule
Set WIP limits to one item per person in each stage:
Example:
- 4 people working in “In Progress”
- WIP limit = 4 items
Logic: This ensures maximum focus and prevents multitasking.
Implementing WIP Limits
Step 1: Communicate the Purpose
Explain to your team why WIP limits are important:
- Better focus and quality
- Faster delivery of work
- Reduced stress and overload
- Improved workflow visibility
Step 2: Set Initial Limits
Start with conservative limits based on your team size:
Small team (2-4 people):
- To Do: 4-6 items
- In Progress: 2-4 items
- Review: 1-2 items
Medium team (5-8 people):
- To Do: 8-12 items
- In Progress: 4-6 items
- Review: 2-3 items
Large team (9+ people):
- To Do: 12-20 items
- In Progress: 6-10 items
- Review: 3-5 items
Step 3: Enforce the Limits
When a column reaches its WIP limit:
- Stop pulling new work into that column
- Focus on completing work in that column
- Identify blockers preventing work from moving
- Address bottlenecks before adding more work
Step 4: Monitor and Adjust
Regularly review WIP limits:
- Weekly reviews of board performance
- Monthly adjustments based on team feedback
- Quarterly optimization based on metrics
WIP Limit Best Practices
1. Start Low and Increase Gradually
- Begin with conservative limits
- Increase limits only when the team demonstrates they can handle more
- Use data to justify changes
2. Make Limits Visible
- Display WIP limits on your board
- Use visual indicators when limits are reached
- Include limits in team discussions
3. Focus on Flow, Not Utilization
- Don’t set limits just to keep people busy
- Focus on moving work through the system
- Accept that some idle time is normal
4. Consider Work Complexity
- Adjust limits based on work complexity
- Complex work may need lower limits
- Simple work may allow higher limits
5. Review Limits Regularly
- Hold regular discussions about WIP limits
- Use team retrospectives to evaluate effectiveness
- Make adjustments based on team feedback
Common WIP Limit Mistakes
1. Setting Limits Too High
Mistake: Setting WIP limits higher than current capacity Problem: Team becomes overwhelmed and quality suffers Solution: Start with lower limits and increase gradually
2. Ignoring WIP Limits
Mistake: Setting limits but not enforcing them Problem: No benefit from the limits Solution: Make limits a team commitment and enforce them consistently
3. Not Adjusting Limits
Mistake: Setting limits once and never changing them Problem: Limits become outdated and ineffective Solution: Regularly review and adjust limits based on team performance
4. Setting Limits Too Low
Mistake: Setting limits so low that team members are frequently idle Problem: Reduced productivity and team frustration Solution: Find the right balance between focus and utilization
5. Not Considering Team Dynamics
Mistake: Setting limits without considering team size and skills Problem: Limits don’t match team capacity Solution: Consider individual and team capabilities when setting limits
Measuring WIP Limit Effectiveness
Key Metrics to Track
-
Cycle Time
- How long work takes from start to finish
- Should decrease with effective WIP limits
-
Throughput
- How much work gets completed
- Should increase or remain stable
-
Work Item Age
- How long items stay in each column
- Should decrease with better flow
-
Blocked Items
- Number of items waiting for something
- Should decrease with better focus
-
Team Satisfaction
- How the team feels about their workload
- Should improve with better work management
Review Questions
Ask these questions regularly:
- Are we completing work faster?
- Is the team less stressed?
- Are we identifying and resolving bottlenecks?
- Is work flowing more smoothly?
- Are we delivering higher quality work?
Advanced WIP Limit Techniques
1. Dynamic WIP Limits
Adjust WIP limits based on conditions:
- Lower limits during busy periods
- Higher limits when team capacity increases
- Seasonal adjustments for predictable patterns
2. WIP Limit Policies
Create clear policies for when limits are reached:
- Pull policies - When and how to pull new work
- Escalation procedures - What to do when limits are consistently exceeded
- Exception handling - How to handle urgent work
3. WIP Limit Visualization
Use visual indicators to make limits clear:
- Color coding when limits are reached
- Warning indicators when approaching limits
- Automated alerts when limits are exceeded
Conclusion
WIP limits are a powerful tool for improving team productivity and workflow efficiency. When implemented correctly, they help teams focus, identify problems, and deliver better results faster.
Remember:
- Start with conservative limits
- Make limits visible and enforceable
- Monitor and adjust based on team performance
- Focus on flow, not just utilization
- Use WIP limits as a tool for continuous improvement
The key to success with WIP limits is to implement them thoughtfully, enforce them consistently, and adjust them based on what you learn about your team’s capacity and workflow.
Ready to implement WIP limits? Check out our guide on Kanban Retrospectives to learn how to continuously improve your process.
Next: Learn how to run effective Kanban Retrospectives to continuously improve your workflow.