What are the benefits and challenges of implementing Kanban across multiple teams or departments?

The core of Kanban is pull. Understanding Kanban implementation well starts with understanding Pull well. You can toss up a ton of cards, but they will proliferate, get stale and fade into meaninglessness unless you set up the pull system among the human actors correctly. Who are the customers? Who are the task providers? Does every card have a customer? Does ever task provider know which customer(s) they are trying to satisfy? Have the customers reviewed the cards to see if they really offer what the customer needs? Have the providers and customers negotiated the cards to ensure they are mutually meaningful? Tasks are only worthwhile if someone wants and needs them.

Looking at any lean system exclusively is you first step down the path of lean failure. The concept of kanban is easily explained above. The application is driving waste out of the processes. Internal kanbans only work if they are small lot pulls that can be replenished quickly. Extend that replenishment time and the lots sizes have to go up to cover. But to run small lots sizes processes need to be flexible and changed over quickly (SMED). The time it takes to actually process must be consistent (Standard Work). Quality defects must be dealt with at the root cause (Problem Solving) or lots are delivered short making the making the time coverage insufficient. Simply constraining a wasteful system will fail without holistic improvement.

Kanban offers a number of system development benefits including providing DevOps teams a complete visual representation of the entire development workflow. This view enables DevOps teams to identify bottlenecks, delays, and opportunities for improvement. This view also helps teams plan and optimize their work processes. Another benefit is Kanban requires close collaboration and communication between teams, allowing for improved coordination of work efforts. This leads to improved sharing of information and ideas. The Kanban approach emphasizes continuous process improvement (CPI), encouraging development teams to continually review and improve their work processes, improving the overall quality of work outputs and outcomes.

At its best, Kanban is just a record of "contracts" between task providers and needy customers. If the contracts deliver only, but also everything, that the customers want, there should be far less waste. Removing waste is the essence of a lean system. Faster, higher quality, more adaptive. Equally important, a good Kanban system will ensure that task providers know their customers and, through them, know how their work matters. Motivation, fitness for purpose, team objectives. It's not the Kanban card system that does this. It is setting up the organization to do pull effectively. That means coaching the actors to communicate effectively. Kanban is just a simple way to aid that.

I agree with the challenges identified. I would add leadership and standardization. Standardized processes can be hard to enforce especially if their is some resistance to change. You might hear a "that's not how I do it" mentality when trying to get folks from different backgrounds, work environments, and experiences to synch with new standard approaches. This is where leadership comes in. Project leaders play a critical role in Kanban implementation. Leaders need to provide a clear vision, allocate appropriate resources to tasks, and be responsive to requests for support when required. A good leader is also a coach and cheerleader for the project, encouraging close collaboration, and leading by example.

When different parts of an organization are engaged in a common development project, at the end of the day they must all wrangle their own agendas into the common goal. A Kanban card is a contract. Someone will do it and someone needs it. Kanban offers a natural way to support the process. Identify all of the cards that cross organizational boundaries. Often, those get orphaned because the supplier and customer don't communicate that often or that well. Concentrate on those boundary crossing cards. Put special effort into pulling the parties together to make sure those are fully defined and mutually agreed. They are an opportunity, not an afterthought.

The key is how the materials get allocated to Kanban. If transacted incorrectly, these materials will be viewed as consumed in the house ERP system. Thus, Kanban inventory can become “ghost” material if system visibility is lost. The best way to use a Kanban system effectively and avoid invisible inventory is to ensure you have transfer (preferably) scan capabilities to show non consumed materials to Kanban then a final scan transacting consumption in production all built into your ERP system. This of course is the best option. You can also manually manage the Kanban inventory in the area it is stored. I’m personally not a big fan of this. This can easily be mismanaged over time and can become more trouble then it’s worth.

Some activities are harder to visualize in pull terms than others. Kanban is optimized for pull. So start by looking for parts of the organization that naturally pull systematically from others. Those are the ones that should engage in Kanban first. Customer service can pull tasks from tech support pretty cleanly. Line managers can pull from HR, but the deliverables may be less well defined. Training can pull from developers, but that gets tricky. Start with the low hanging fruit. Build success. Expand from there.