Kanban and Lean Manufacturing: Tracking Completed Work

Kanban (whose name comes from a Japanese word meaning "signboard") is a visual system used in companies working with lean manufacturing to track the work to be done and how it moves along the processes of an organization. The tool, however, is extremely useful, if properly adapted, in any reality that wants to operate in a regime of quality.

This system, which helps us understand how ongoing work is progressing, can be physical – therefore, there is an actual card attached to the material being processed that specifies which phase it is in (or with a simple post-it note that follows the progress of a specific task on a board representing the process) – or electronic if we use an application.

In production, for example, the Kanban methodology starts when an order comes in and the related materials begin to follow the flow of processes that will lead the product to be shipped to the final customer. It can be, in the simplest example that may come to mind, a card with a simple inventory number that is attached to a specific part. Before the part is installed on the final product, the card is detached and sent back to whoever manages the supply chain of that part to ensure that a new one is procured (through the department warehouse, the company warehouse, the production department if the part is made internally, or the external supplier of reference).

The principle that guides the Kanban methodology, therefore, is that you do not order or produce something until a card attached to something similar that has reached the end of its processing is freed up.

If I use a certain piece to make a product, then, I will get a new piece that will re-enter the process and I will know that I have to do it because the card that accompanied the part throughout its journey, from picking it up in the warehouse to assembling it, will be detached from the piece in question and will remain alone to testify that a new part is needed to be put into production or to be taken from the warehouse or to be ordered from the supplier.

The Kanban system, therefore, can be called a "pull system" because it is a system that is "pulled" from downstream and that is dictated by the consumption of individual pieces/products. If we want to try to adapt this methodology to the projects that a project manager has in progress, for example, we could have a simple board divided into three columns with the following written at the top:

• "to do"
• "in progress"
• "done"

and use simple adhesive notes with information relating to the specific tasks to be performed within a given project written on them to follow the progress along the three columns. For example, we could have:

• activity 1 of project 4 - "to do"
• activity 3 of project 2 - "in progress"
• activity 5 of project 1 - "in progress"
• activity 1 of project 3 - "in progress"
• activity 3 of project 1 - "done"
• activity 4 of project 1 - "done"

Also in this case, you do not start working on a new activity if you have not first completed another activity that was being carried out. The completed activity "pulls" another activity to be carried out. In the example we have made, we could start working on two new activities, since we have completed two others. Obviously, it is necessary to define upstream how many activities we can manage simultaneously and then adhere to that maximum number, replacing a new task with each completed activity (just as it is necessary to define how many parts we want to have simultaneously in processing).

A physical or virtual board to follow such a discussion can, of course, be much more complex and reflect the progress of an entire process, but the method still applies in the same way, ensuring that the adhesive notes move along the process flows and ensuring that at any moment there is a clear visual indication of the activities in progress. Kanban works based on precise rules:

1. The workflow must always be clearly visible, i.e., you must be able to visualize, through a physical or electronic support, the different steps of the processes;
2. Within the specified processes, there can only be as many "items" (pieces, parts, tasks, etc.) as specified upstream, i.e., WIP (Work in Progress, pieces in processing) must be limited. Limiting WIP helps the people working on a given process to finish what they are doing before starting something new and to communicate to all interested parties that there is a limited capacity related to the process and that everything must be carefully planned;
3. New "items" are requested from below when other "items" exit the process;
4. No "item" moves within a process without a Kanban (reference card).

The method is quite simple to apply to the existing workflow because any necessary changes can be implemented gradually over a certain period of time, depending on the receptivity of those working on a given process.

Kanban, therefore, encourages small incremental changes instead of radical changes that could cause real resistance from collaborators. As part of the visualization of the process, another fundamental aspect of the Kanban methodology is to explicitly define the rules of the process and its guidelines. In this way, there will be a common basis from which all participants in the process can start to understand every type of work that is done in that area.

Some examples of clear rules could be: the definition of when an activity can be considered complete, who must put a new item into the process, with what modalities, etc.

Another advantage of the Kanban methodology is the fact that it encourages the so-called "feedback loop" i.e., real circuits of immediate and continuous controls, responses, and reviews that constitute an integral part of any good system to have the work in progress continuously under control. Being constantly updated if something in the process is not working is a guarantee to work well and to provide the right product or service to the customer in the shortest time.

Under this aspect, Kanban can also be seen as a very powerful tool for continuous improvement because it helps to adopt small changes and to improve gradually through the adoption of the scientific method: a hypothesis is formulated, it is tested, and the necessary changes are implemented, depending on the result from the test. Moreover, working in this way, it is quickly seen if the change made brings the expected advantages, because it is enough to observe how the work proceeds to evaluate if the change has made the process better or worse. In the second case, it will be easy to immediately return to the previous situation.

The two main indicators of the Kanban methodology are:

1. The lead time – the period of time that elapses between the appearance of a new task to be performed and its removal from the flow;
2. The cycle time – the period of time that elapses from when the new task enters the "Work in Progress" phase and someone starts working on it until the end of the work. Obviously, the goal is to reduce the duration of both these times as much as possible.

When to use Kanban

Kanban is a methodology that is very convenient to use when you are dealing with varying and unpredictable work rhythms, characterized by priorities that change very frequently. In this case, Kanban serves to manage these variants quickly thanks to its great adaptability.

It is a method that also works well in those realities in which there is flexibility regarding the delivery of the work or where there are long deadlines because it provides an efficient model to achieve the objectives.

Finally, when there is a lot of work, Kanban is the perfect solution to manage it in the best way, since the collaborators themselves "pull" the work downstream, without someone assigning them the tasks to be performed and, in this way, it can be avoided that there is too much Work in Progress and that you find yourself with too many things to do at the same time. Kanban is the right methodology even if you want to start seeing some results immediately or if you are dealing with teams composed of many people because the few rules necessary for its implementation are learned quickly and without great effort.

Advantages of Kanban

1. There are no dead times linked to the waiting for materials and the assignment of work, and this leads to an increase in the efficiency of the flows;
2. The members of the work team have the opportunity to see at any time the state of the work in progress, and this improves communication and the possibility of collaborating to find solutions;
3. The system is extremely flexible because you can add and remove processes until they enter the flow.

Disadvantages of Kanban

1. For a system like that of Kanban to work, it is necessary to have a well-defined process and that all those who work on the process are perfectly aware of their role. Without these two fundamental premises, the process could stop at any moment;
2. The flow must continue to flow, so constant work is required from everyone. If someone stops, people downstream are left without activities to carry out;
3. This methodology has no time constraints, so an activity to be carried out requires the necessary time, and this could create problems in terms of deadlines to be met;
4. There is a lack of a clear definition of priorities.