Multilevel WIP (Work In Progress) on Kanban & Scrum boards
This feature is available from version 4.1
Overview
Multilevel WIP feature allow board administrators to build a true Kanban PULL system directly on any Jira Scrum or Kanban board.

How Multilevel WIP limits and PULL system improves your workflow?
Expose blockers and bottlenecks with PULL system
Instead of pushing tasks forward, team members pull their tasks when they’re ready. That will increase visibility what is actually being worked on. Using multilevel WIP configuration split each major stage like development, tests or release into multiple steps:
In Progress
Done
That way you’ll be able to identify bottlenecks in your process and resources even without daily standups.
The advantages of the pull system are listed below,
Improves the efficiency of the workflow,
Reduces waste of resources
Manages and controls the workflow
Ensures that employees are occupied with one work
Reduces the waste in the processes
Reduces the waiting time in the processes
Enhance productivity
Work is done at a faster rate
The performance of the team is enhanced
The quality of the products is high and meets the customer requirements
Helps in managing the issues and problems that can be attended early in the cycle.
Helps to quickly adapt to the changes that may appear in the flow.
Enhance and optimizes the team capacity
Stabilizes the workflow by putting the WIP-Limits and pull system
Visualise and set limits at high level
Combine multiple statuses to represent project stages or teams and set WIP limits for each of them. For example development stage can utilise two teams and few different statuses. With WIP limits you’ll be able to tell if any of them is missing tasks or is overloaded.
Useful resources
How to build a Scrum PULL system
What is a WIP Limit
How to calculate WIP limits
Configuration
Multilevel WIP can be configured on each board on the Board->Columns tab

Use the Add WIP header button to create a new header
Drag & drop headers above existing statuses in your process to row 1 or row 2
Placing the same Multilevel WIP headers next to each other will create a combined WIP group on the board.
On the right side set WIP header limits
A combined WIP will calculate all tasks from the columns below.
To remove a header from a column use the X icon
Drag & drop will not remove a WIP header
Choose your boards Look & Feel by enabling background or underscore colour