Usage and Importance of Queues in Kanban

Why queue?
Not only delivering quality code but also delivering it at 'regular' intervals is very important. The manager along with his team should decide on how many days/weeks should that interval / cycle be.
Queue can be implemented in various ways in kanban.
1. We can divide the development in 2 columns into 'implementation' column and 'ready to test' column. This 'ready to test' column will act as a queue for test column.
2. We can divide our wishlist in 2 columns into 'wishlist' and 'queue'. We should implement all the features in the queue before taking in the features from wishlist which can be done only when the new cycle starts.

Example of queue implementation in kanban:

At the start of phase:

We try to pull some features wishlist and transfer them into queue which can be completed in 1 cycle.

During implementation of present features in queue

During the implementation of the cycle, we will not be able to pull anymore features or requests from wishlist, we will only work on the features in the queue.
Any new requests or features will be thrown into wishlist.