28. May 2020

Can Spaghetti help LEAN your process

By Riccardo Giacometti

The spaghetti diagram is a tool that displays the paths of guests, employees and material flows within a workplace layout (e.g., a restaurant or hotel room). The movements of employees, suppliers and guests as well as materials are clearly visualized as lines (the path of each object in a different color) from points A to B on a floor plan. Each work step is recorded and inefficiencies are exposed in the form of unnecessary trips or overly long distances traveled, thus identifying non-value-adding activities. This method can also be used to identify crossed paths and risk areas. The spaghetti diagram is so-named because the routes and material flows are shown as a bundle of lines that resembles spaghetti. It is a simple yet effective tool for optimizing workplace processes.

The methodology can be used to answer the following questions:

  • How efficient are the employees’ work paths?
  • Is the use of space in the restaurant / room optimal?
  • Is the workplace organization suitable for the current hygiene processes?
  • Is the workplace layout efficient?
  • Are there risk areas that require special attention?

Take a look at this example of a production problem. I am convinced that you can transfer it to your company. https://youtu.be/No2jRTzeC5c

Aim of the spaghetti diagram

The spaghetti diagram represents an actual recording of the situation. No optimizations or solutions are inserted into the diagram. An exact observation of the current situation on site is necessary. When creating the spaghetti diagram, the two main types of waste, transport and movement, are shown and visualized. For the spaghetti diagram, we distinguish between movement or transport of products or people through a process.

The spaghetti diagram can therefore be used wherever movement or transport occurs. This can be in a restaurant, kitchen or in a room, office workplace or reception. The goals can be differentiated based on the view of the situation.

Especially in the current situation with COVID-19, it is important to know how everyone (employees, guests, materials etc.) moves, in order to prevent contamination.

The primary goal when creating a spaghetti diagram is to visualize wastage and the interpretation of movement (paths). This first step is not about removing them. It is important to start with a spaghetti chart from a clearly defined working area. Do not make it complicated!

Create A Spaghetti Diagram

Sketch the analysis area

The work area to be observed is drawn in detail and to scale. On this basis, the paths can be easily calculated during the later evaluation. It often makes sense to use a floor plan of the work area. It is much easier and certainly many floor plans are readily available in the form of a table plan. Alternatively, checkered paper and a pen are sufficient.

All tables (e.g., in the restaurant) and facilities are drawn in.

Every object to be observed (employees, guests, suppliers, cleaning staff, etc.) is assigned a color or various symbols.

Set period

The period of observation is defined. A representative time period must be selected, since the observation is the basis of the actual analysis. The actual analysis is the input variable for the optimization. If the time period is not representative, the basis for the optimization is not meaningful.

Create diagram

Each transport or movement between individual locations is documented with a line. The line follows the transport or movement of the object. Do not combine several movements into one line. Draw a separate line for each individual movement.

It is good practice not only to observe the process, but also to perceive the role of the object itself. This means that you walk the path parallel to the object yourself or carry out the movements of the object yourself. This leads to a much deeper understanding of the situation.

Mark crossings of paths, traffic jams, guest contacts, etc. with individual symbols.

Record all movements. Movements are often not recorded because the surveyor does not consider them to be relevant or representative. However, you should also record these movements. It is precisely these movements and transportations that cannot be planned at the desk, but they are part of the daily routine of the process and represent a huge potential for ways to optimize the process.

The more actions that take place between individual process points, the more lines will appear on the diagram.

Evaluate results

The visualization of the observations allows a rough and quick assessment of the quality of the process. The more unproductive the process flow is, the more confusingly the lines will be arranged on the layout. As the number of lines on the layout increases, transport and movement determine the process.

Data additionally recorded during the visualization allow a more detailed evaluation of the actual situation. In so doing, you can analyze parameters such as running and handling distances, interruptions, transport distances and times, and many other similar data. The collected data are the basis for further analyses and show possible starting points for solutions.

Often the observer has revealed a variety of possibilities for improvement during the observation alone. It has been shown that, through a corresponding training effect, observers can discover and name individual fields of action from observation to observation faster and more effectively.

Reduce transport and movement

Based on the analysis, the potential steps for optimization can then be identified and implemented. For this purpose, the following questions must be answered using examples:

  • How can unhelpful contacts be avoided?
  • How can transports and movements be reduced?
  • How can unhelpful transports and movements be shortened and avoided?
  • Can the location of equipment be changed in order to concentrate processes in a single location?
  • Can activities be combined at different locations in order to positively influence transports and movements?

Use very basic tools for visualization. Often paper and pen are sufficient to document the actual state on site. Who would have thought that I would present something without the involvement of a computer or an app? It is very easy to make corrections or additions to the diagram with paper and pencil. Use your time for the exact observation and not for the operation of software.

This exercise does not take long but gives certainty and the adjustments can be made quickly and safely. Good luck and have fun!