Spaghetti diagram

Spaghetti diagram (Spaghetti chart, Spaghetti plot or Spaghetti model) is a visual method of presenting the movement of product, service, people or information in the work process. The graphics line system shows the way that objects move at a work station, in a manufacturing site or in a company building. The name "spaghetti" is used due to the fact that the diagram shows a lot of resemblance to noodles.

Conditions for applying the method

The method is used in lean management to optimize the work or theproduction process. The application of the tool works best when employees devote too much time to moving between work stations or transferring raw materials between the following stages of the production process. The Spaghetti diagram helps recognize inefficiencies in the organization, e.g. the printer is too far from the employee and as a result, his work efficiency is reduced by the waste of time. In addition, the model presents the information flow, as well as indicates dependencies and responsibilities between individual objects in the process. The introduction of this tool can analyze the situation and improve the current conditions.

Ways of preparation the diagram

The development of the Spaghetti diagram is possible with the help of two different methods:

• Method A,
• Method B.

Choosing a procedure depends on the kind of movement and the complexity of the process.

Method A

When thinking about implementing this method, it would be better if the process was complex, because in this conditions the method is the most successful. The second relevant factor is the multitude of positions and the resulting awareness of the diversity of simultaneous flows, e.g. employees, raw materials, documents. The realisation of this method consists of a few steps. First of all, it is important to define a project team, usually consisting of 3-4 people. The next step is preparing a place, a scheme of the analyzed space and office supplies (coloured markers, balls and notes, flip chart paper, sticky tape etc.). In this case, for proper preparation of the Spaghetti diagram influences the participation of the people involved in the project. Supplementing the diagram is built on sticking coloured tapes after each stage of the process.

Method B

This method is used in the study of a simpler process, e.g. it concerns one production line. Usually, only one kind of process at a time is considered for observation, e.g. employee movement. The work on the model begins with the preparation of the plan of the observed place with all its equipment. Each cycle of moving the object is marked with a different colour, which helps examine the entire process. The determined path in the model gives the possibility to calculate its length, and then to analyze the efficiency and optimization.

Examples of Spaghetti diagram

• One example of a Spaghetti diagram can be seen in a manufacturing facility, such as a car factory. In this case, the diagram can trace the movement of a car as it moves through the assembly line, showing the different steps it goes through and how it is moved from one station to the next.
• A second example of a Spaghetti diagram is in a warehouse setting. This type of diagram can be used to trace the movement of goods as they are moved from the receiving area to the various storage areas and then out to the shipping dock.
• A third example of a Spaghetti diagram is in an office setting. This type of diagram can be used to trace the movement of documents and information through a complex set of processes. It can show the different steps that documents must go through before they are completed, as well as any other processes that may be involved.

Advantages of Spaghetti diagram

A Spaghetti diagram is a simple and effective way of visualizing the movement of product, service, people or information in the work process. It has a lot of advantages, such as:

• It enables quick identification of all movements and processes, as well as their corresponding times, distances and paths.
• It is easy to understand and interpret, even for non-specialists.
• It allows for rapid evaluation of the efficiency of the work process and its potential for improvement.
• It can be used to quickly identify and eliminate waste and redundancies in the work process.
• It helps to identify the most efficient paths and routes for the movement of product, service, people or information.
• It helps to discover and remove any obstacles, bottlenecks and delays in the work process.

Limitations of Spaghetti diagram

Spaghetti diagram is a useful visual tool for understanding the movement of product, service, people or information in the work process. However, it has several limitations:

• It does not provide any quantitative data, so it is difficult to draw conclusions from it.
• It is difficult to identify the bottlenecks and inefficiencies in the system.
• It cannot be used to analyze the performance of the system and the efficiency of its components.
• It is not suitable for analyzing complex systems with many components.
• It is difficult to compare different systems and different scenarios with a spaghetti diagram.

Other approaches related to Spaghetti diagram

Spaghetti diagrams are related to other approaches, such as:

• Process mapping - which focuses on visualizing the steps in a process,
• Value stream mapping - which visualizes the flow of information and materials in a process,
• Activity network diagrams - which uses nodes and arrows to represent activities and their logical relationships,
• Flowcharts - which are graphical representations of a process,
• Storyboards - which represent a process as a series of images, and
• Kaizen events - which are short-term improvement initiatives that involve team members from different departments.

In summary, Spaghetti diagrams are related to a range of other approaches, all of which seek to visualize the flow of a process. These approaches can help organizations to identify areas for improvement and develop more efficient workflows.

Footnotes

Spaghetti diagram — recommended articles

Activity chart — Interrelationship diagram — Value stream mapping — Line balancing — 7 quality tools — Matrix diagram — Pareto chart — Business process mapping — Operational research

References

• Balaji K., Senthil Kumar V. S. (2014), Application of Lean Principles to Reduce the Non-Value Adding - Transportation Activities in aRubber Components Manufacturing Industry, 5th International & 26th All India Manufacturing Technology, Design and Research Conference;
• Daley A. T. (2009), Using Spaghetti Diagram to Improve Process Flow, Tools and Knowledge: Your Management Survival Kit;
• Martin J. M. (2008), Lean Six Sigma for the Office, CRC Press;
• Protzman Ch., Mayzel G., Kerchpar J. (2010), Leveraging Lean in Healthcare: Transforming Your Enterprise into a High Quality Patient Care Delivery System, CRC Press;
• Ross G., Jeffrey B. (2009), Tools for Success;
• Senderská K., Mareš A., Václav Š. (2017), Spaghetti diagram application for workers' movement analysis, UPB Scientific Bulletin, vol. 79;
• Sproull B. (2012), The Ultimate Improvement Cycle: Maximizing Profits through the Integration of Lean, Six Sigma, and the Theory of Constraints, Productivity Press

Author: Patryk Schmidt