The spaghetti diagram is a tool used to provide a clear view of the flow of parts or individuals.
It takes its name from its resemblance to a dish of spaghetti. In general, flows intermingle in its first trace.
This visualization is used to identify redundant flows, recurring crossings and measure the path traveled by each product or person.
It supports the re-implantation or geographical reorganization of machines or services to limit travel time and their non-added value.
Designing a spaghetti diagram in 5 steps
- Define the service, workshop and geographic area covered by the study. For a physical process it’s pretty simple. For a virtual process, it is necessary to identify the different people who are part of the process, but also the systems, servers or tools used.
- Get a map of the area. The plan must contain the different machines or parts in which the products will be processed, as well as the intermediate storage areas. In a virtual world, we can schematize the different sectors and connect them with points. We can also indicate on the map the different systems or servers used by the process.
- List the different types of products or services that are transformed by the process. This definition can be adapted to different sectors. For example, for a hospital, we will list the different types of patients that must be treated (emergency, punctual appointments, outpatient surgery, …), for a plant, we will list the products.
- For each product, plot the path taken, including the storage or waiting zones.
- Measure the distance traveled by each product. This measure will be used to compare the initial situation with the proposed change, and to calculate the cost-effectiveness of the changes. In the virtual, we can count the number of steps, or the number of kilometers of network cable borrowed.
How to design a useful spaghetti diagram?
You have to have the maximum stakeholders while drawing. In fact, there is nothing more complex than to imagine what happens in another sector or service. Ideally, before getting into the drawing, the team will “walk” the process during a Gemba Walk.
Spaghetti diagram examples
(plan copyright : Atelier Hall Idasiak)
In this case, it is the flow of patients that is represented. But we could also have worked on the flow of employees from the radiography center. It all depends on the objectives of the study. A good 5W’s will ensure that the study is about the right topic.