What is different between Pull System (Kanban) and Waterfall?

Following the image above I see that the work have to depend for each step, it means when we start for Development phase, the QA in scrum team could not start their work...am i correct?

I wonder what is different between Kanban and Waterfall. In waterfall we will do phase to phase it means when we finish 1 step so we can move the another step

How large is the batch of work, and how long must you wait until any one item is completely finished?

Can you see how the deliberate limiting of work-in-progress might lead to a capacity-based system...one through which work is drawn or pulled rather than pushed, as it is completed? What effect might workflow policies have on predictability and forecasting?

How large is the batch of work, and how long must you wait until any one item is completely finished?

For example when the sprint start, we will do the development in 1-2 day(s) that is the average time for development, then this item will move to testing phase, we will wait for 1-2 days from the begining until the item from development column move to the testing column.

Can you see how the deliberate limiting of work-in-progress might lead to a capacity-based system...one through which work is drawn or pulled rather than pushed, as it is completed? What effect might workflow policies have on predictability and forecasting?

Can you give more detail about this point?

Waterfall pushes items from left to right and everyone focusses on their specific work and not the whole body of work. In waterfall, people work work in specific areas and do not venture outside of those areas.  For example a developer writes code but they will not test. Kanban pulls work from the left to the right and everyone focusses on getting work from start to finish as fast as possible without sacrificing quality or value. In Kanban everyone is willing to work in any area if the need is there.  

On your board you are creating a number of queueing points.  Your Development Done column with an infinite limit creates a place for developers to push code that has to wait.  Then you have the Ready for Test column which is another queue.  There is potential to have a large percentage of your work items sitting in those queues if developers are able to complete work faster than your testers.  That usually leads the developers to want to pull more work into the Sprint so that they "have something to do".  

Kanban pulls items across the board and focuses on getting the right hand columns cleared before any new work enters into the board.  In Kanban, the Development Done column would have a limit just like all others.  If that column meets it's Work In Progress limit, the people that do work on the left hand side of the board would pitch in to help clear the right hand side so that work can start flowing across the board.  

Hope this helps. 

Wow, that's great!!!!

Thank you very much for your explanation Daniel

Check out the PSK guide for full details on how you can use Scrum with Kanban

Waterfall methodology is a linear management method. 

At the beginning of the project, both the development team and the stakeholder team gather to build a project plan based on the project requirements. The goal is made to fulfill these requirements. 

Each phase of the project follows into the next stage; therefore, it is called Waterfall methodology. It is worth mentioning that each project phase happens once, so you can not come up when you come down.

The main stage of the Waterfall is planning. All of the project requirements, list of features, and application functionalities must be clear to get mapped between the team members.

In the planning phase, both the development team and the customer needs to have a clear vision about the final product.

According to the specifications, the development team works on the architecture and design of the app.

Agile methodology is a collaborative, self-organizing, and cross-functional approach to completing work and its requirements and developing a software or an app. Kanban and Scrum are both considered types of Agile. 

Kanban is translated as “board” or “card” in Japanese.

The methodology first appeared in the 1940s Toyota factory to help with inventory inefficiencies.

But now, Kanban counts as a methodology to manufacture and deliver products just in time. 

In Kanban, there are two main aspects: Kanban board, and Kanban cards.

The Kanban board represents the work process, and the Kanban cards represent project details. 

Both the board and the cards help with the adjustment of the workflow. 

There is a Work in Process (WIP) limitation in Kanban boards that all of the development team should know about.

In the Kanban board, only a particular number of projects should be put in every column. All of the people involved in the production and planning should know about WIP limitations. 

For example, a Kanban board can have columns like backlog, progress, test, and done. In each column, there are a particular number of Kanban cards that represent the work in progress. On these cards, the team members can see the work in progress, the job done, etc.

Trello counts as a perfect Kanban board to visualize your work and follow up on the progress.

In Kanban, the workflow needs to be smooth in the whole weekly or monthly schedule. Therefore, if there is a day with more WIP cards in the Kanban board, there is a bottleneck that the managing team needs to solve.