Two basic principles behind Kanban

One is the Limit WIP quantity

The other is to pull the flow of work through the signal card transfer mechanism only when there is available capacity.

How to establish WIP quantity? Some favor each engineer to do one thing at a time, some think that an engineer does two things best, and some things always depend on and wait. In fact, there is no magic number for all companies. It is recommended to start with a number and then continue to observe whether the figure is in line with the actual situation, and if so, gradually adjust to a more stable figure.

Some companies have different categories of WIP, which can be divided into WIP lanes, such as receiving 3 bugs at the same time, doing two small enhancements, and a clerical change. This way, when WIP is done, you know that type of backlog needs to be pulled into the workflow from the input queue.