Kanban is rapidly gaining popularity as the alternative path to agility, however, there are some common questions and misconceptions that we see frequently. Here are five questions and answers.
February 2020
1. Where does systems thinking fit in designing a Kanban system?
STATIK; the system thinking approach to implementing Kanban. We always want to think of the system as a whole and avoid local optimization. The steps in this process are not necessary sequential, but iterative, using learning from one step to inform and influence the others. The steps are:
Step 0: Identify Services
For each service:
Step 1: Understand what makes the service fit for purpose for the customer
Step 2: Understand sources of dissatisfaction with the current system
Step 3: Analyze demand
Step 4: Analyze capability
Step 5: Modal workflow
Step 6: Discover classes of service
Step 7: Design the Kanban system
Step 8: Socialize the design and negotiate implementation
2. When setting a WIP limit you should always take into account the size of your team -- true or false?
FALSE. For example, single piece flow sets WIP to one regardless of size of the team. It is more about balancing the constraints and capacities of the system and avoiding bottlenecks. However, setting a WIP limit of the size of the team (or a little more) may be a decent place to start.
3. What are the disadvantages of using value stream mapping in knowledge work?
Value stream mapping captures a workflow and focuses on timing each step in order to optimize it. In knowledge work, accelerating one step may cause issues downstream due to quality. Also, Kanban boards track knowledge discovery rather than handoffs. The column headings in a Kanban board reflect the dominant activity, not the only activity (e.g. this is why we can have bug fixing in a “testing” column). Value stream mapping was created for manufacturing. On the other hand, value-stream mapping can work well for automated DevOps pipelines, since humans are not involved.
4. What's the difference between work item type and class of service?
Work item types capture different kinds of work, such as Epics, Defects, User stories, and the like. At a Starbucks, work items might include Latte, espresso, breakfast sandwiches, and mints. Classes of service are how items are handled. For example, one user story may be expedited, while another may have a fixed due date. At Starbucks, they might receive a request at 11 for a latte to be picked up at noon– that would have a fixed date class of service, and the team would probably not start working on it until about 11:55am. By contrast, if the mayor walked in and made an order, that would probably get expedited!
5. Why is lead time not measured from concept to cash?
The Kanban system starts when a work item is committed to, and stops at the first unbounded queue. We should also differentiate “customer lead time” versus “system lead time” to be more clear. For example, a Starbucks with a given number of workers can produce coffee at a certain rate, regardless of how many people are in line. The last one in line will have a longer wait. If we want to handle a long line of customers, we should look at the system and see where the constraint is–do we need more cashiers or more baristas? If long lines persist, perhaps it is time to expand the store, or even open up a new one! Maybe that is why we often see multiple Starbucks within 3 blocks of each other in NYC…
