Kanban
is a visual system for managing work as it moves through a process. Kanban
visualizes both the process (the workflow) and the actual work passing through
that process. The goal of Kanban is to identify potential bottlenecks in your process
and fix them so work can flow through it cost-effectively at an optimal speed
or throughput.
A Kanban system ideally controls the entire
value chain from the supplier to the end consumer. In this way, it helps avoid
supply disruption and overstocking of goods at various stages of the
manufacturing process. Kanban requires continuous monitoring of the process.
Particular attention needs to be given to avoid bottlenecks that could slow
down the production process. The aim is to achieve higher throughput with lower
delivery lead times. Over time, Kanban has become an efficient way in a variety
of production systems.
History
of Kanban
In
the late 1940s, Toyota found a better engineering process from an unlikely
source: the supermarket. They noticed that store clerks restocked a grocery
item by their store’s inventory, not their vendor’s supply.
Only
when an item was near sellout did the clerks order more. The grocers’
“just-in-time” delivery process sparked Toyota engineers to rethink their
methods and pioneer a new approach—a Kanban system—that would match inventory
with demand and achieve higher levels of quality and throughput.
So
how’d they do all that?
In
simplest terms, by better communication through visual management.
Kanban is Japanese for
“visual signal” or “card.” Toyota line-workers used a kanban (i.e., an actual
card) to signal steps in their manufacturing process. The system’s highly
visual nature allowed teams to communicate more easily on what work needed to
be done and when. It also standardized cues and refined processes, which helped
to reduce waste and maximize value.
A
new application of Kanban emerged for knowledge work as early as 2005, and an
inquisitive community formed in 2007 around the leadership of David J.
Anderson, Jim Benson, Corey Ladas and others. Their resulting body of knowledge
was influenced not only by the Toyota Production System but also by the work of
W. Edwards Deming, Eliyahu Goldratt, Donald Reinertsen and other thought
leaders.
Kanban Method: Principles & Practices
The
Kanban Method follows a set of principles and practices for managing and
improving the flow of work. It is an evolutionary, non-disruptive method that
promotes gradual improvements to an organization’s processes. If you follow
these principles and practices, you will successfully be able to use Kanban for
maximizing the benefits to your business process – improve flow, reduce cycle
time, increase value to customer, with greater predictability – all of which
are crucial to any business today.
The
four foundational principles and six Core Practices of the Kanban Method are
provided below:
Foundational Principles
1. Start with what you are doing now: The Kanban Method
(hereafter referred to as just Kanban) strongly emphasizes not making any change to your
existing setup/ process right away. Kanban must be applied directly to current
workflow. Any changes needed can occur gradually over a period of time at a
pace the team is comfortable with.
2. Agree to pursue incremental,
evolutionary change: Kanban
encourages you to make small incremental changes rather than making radical
changes that might lead to resistance within the team and organization.
3. Initially, respect current roles,
responsibilities and job-titles: Unlike other methods, Kanban does not
impose any organizational changes by itself. So, it is not necessary to make
changes to your existing roles and functions which may be performing well. The
team will collaboratively identify and implement any changes needed.
These three principles help the organizations
overcome the typical emotional resistance and the fear of change that usually
accompany any change initiatives in an organization.
4. Encourage acts of leadership at all
levels:
Kanban encourages continuous improvement at all the levels of the organization
and it says that leadership acts don’t have to originate from senior managers
only. People at all levels can provide ideas and show leadership to implement
changes to continually improve the way they deliver their products and
services.
Core Practices of the Kanban Method
1. Visualize the flow of work: This is the fundamental
first step to adopting and implementing the Kanban Method. You need to
visualize – either on a physical board or an electronic Kanban Board, the
process steps that you currently use to deliver your work or your services.
Depending on the complexity of your
process and your work-mix (the different types of work items that you work on
and deliver), your Kanban board can be very simple to very elaborate.
Once you visualize your process, then you can visualize the current work that you and your team are doing. This can be in the form of stickies or cards with different colors to signify either different classes of service or could be simply the different type of work items. (In SwiftKanban, the colors signify the different work item types!)
If you think it may be useful, your
Kanban board can have different Swim Lanes, one for each class of service or
for each work item type. However, initially, to keep things simple, you could
also just have a single swim lane to manage all your work – and do any board
redesign later.
2. Limit WIP (Work in Progress): Limiting work-in-progress
(WIP) is fundamental to implementing Kanban – a ‘Pull-system’. By limiting WIP,
you encourage your team to complete work at hand first before taking up new
work. Thus, work currently in progress must be completed and marked done. This
creates capacity in the system, so new work can be pulled in by the team.
Initially, it may not be easy to
decide what your WIP limits should be. In fact, you may start with no WIP
limits. The great Don Reinertsen suggests (he did so at one of the Lean Kanban
conferences) that you can start with no WIP limits and simply observe the
initial work in progress as your team starts to use Kanban. Once you have
sufficient data, define WIP limits for each stage of the workflow (each column
of your Kanban board) as being equal to half the average WIP.
Typically, many teams start with a WIP
Limit of 1 to 1.5 times the number of people working in a specific stage.
Limiting WIP and putting the WIP
limits on each column of the board not only helps the team members first finish
what they are doing before taking up new stuff – but also communicates to the
customer and other stakeholders that there is limited capacity to do work for
any team – and they need to plan carefully what work they ask the team to do.
3. Manage Flow: Managing and improving
flow is the crux of your Kanban system after you have implemented the first 2
practices.
A Kanban system helps you manage flow
by highlighting the various stages of the workflow and the status of work in
each stage. Depending on how well the workflow is defined and WIP Limits are
set, you will observe either a smooth flow within WIP limits or work piling up
as something gets held up and starts to hold up capacity. All of this affects
how quickly work traverses from start to the end of the workflow (some people
call it value stream).
Kanban helps your team analyze the
system and make adjustments to improve flow so as to reduce the time it takes
to complete each piece of work.
A key aspect of this process of
observing your work and resolving/ eliminating bottlenecks is to look at the
intermediate wait stages (the intermediate Done stages) and see how long work
items stay in these “handoff stages”. As you will learn, reducing the time
spent in these wait stages is key to reducing Cycle Time.
As you improve flow, your team’s
delivery of work becomes smoother and more predictable. As it becomes more
predictable, it becomes easier for you to make reliable commitments to your
customer about when you will get done with any work you are doing for
them. Improving your ability to forecast completion times reliably is a big
part of implementing a Kanban system!
4. Make Process Policies Explicit: As part of visualizing
your process, it makes sense to also define and visualize explicitly, your
policies (process rules or guidelines) for how you do the work you do.
By formulating explicit process
guidelines, you create a common basis for all participants to understand how to
do any type of work in the system. The policies can be at the board level, at a
swim lane level and for each column. They can be a checklist of steps to be
done for each work item-type, entry-exit criteria for each column, or anything
at all that helps team members manage the flow of work on the board well.
Examples of explicit policies include the definition of when a task is
completed, the description of individual lanes or columns, who pulls when, etc.
The policies must be defined explicitly and visualized usually on the top of
the board and on each lane and column.
5. Implement Feedback Loops: Feedback loops are an
integral part of any good system. The Kanban Method encourages and helps you
implement feedback loops of various kinds – review stages in your Kanban board
workflow, metrics and reports and a range of visual cues that provide you continuous
feedback on work progress – or the lack of it – in your system.
While the mantra of “Fail fast! Fail
often!” may not be intuitively understood by many teams, the idea of getting
feedback early, especially if you are on the wrong track with your work, is
crucial to ultimately delivering the right work, the right product or service
to the customer in the shortest possible time. Feedback loops are critical for
ensuring that .
6. Improve Collaboratively, Evolve
Experimentally (using the scientific method): The Kanban Method is an evolutionary
improvement process. It helps you adopt small changes and improve gradually at
a pace and size that your team can handle easily. It encourages the use of the
scientific method – you form a hypothesis, you test it and you make changes
depending on the outcome of your test.
As a team implementing Lean/ Agile
principles, your key task is to evaluate your process constantly and improve
continuously as needed and as possible. The impact of each change that you make
can be observed and measured using the various signals your Kanban system
provides you. Using these signals, you can evaluate whether a change is helping
you improve or not, and decide whether to keep it or try something else.
Kanban systems help you collect a lot
of your system’s performance data – either manually, if you use a physical
board, or automatically, if you use a tool such as SwiftKanban. Using this
data, and the metrics it helps you generate, you can easily evaluate whether
your performance is improving or dropping – and tweak your system as needed.
How does Kanban work? - The Concept
Kanban is a non-disruptive evolutionary
change management system. This means that the existing process is improved in
small steps. By implementing many minor changes (rather than a large one), the
risk to the overall system is reduced. The evolutionary approach of Kanban
leads to low or no resistance in the team and the stakeholders involved.
The first step in the introduction of Kanban is to
visualize the workflow. This is done in the form of a Kanban
board consisting of a simple whiteboard and sticky notes or cards. Each card
on the board represents a task.
In a classic Kanban board model, there are three
columns, as shown in the picture above:
- “To
Do”:
This column lists the tasks that are not yet started. (aka “backlog”)
- “Doing”:
Consists of the tasks that are in progress.
- “Done”:
Consists of the tasks that are completed.
This simple visualization alone leads to a great
deal of transparency about the distribution of the work as well as existing
bottlenecks if any. Of course, Kanban boards can show elaborate workflows
depending on the complexity of the workflow and the need to visualize and
examine specific parts of the workflow to identify bottlenecks in order to
remove them.
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