Have you ever wondered how efficiently your workplace is organised and how your workflows are linked? And is it possible to optimise the latter?
In most cases you can. But how do you find out? How do you analyse all the processes and identify the bottlenecks?
We will tell you and show you.
What is a Spaghetti Diagram?
A spaghetti diagram is a miniature visual map of an employee’s physical movements in the workplace. Such diagrams make it easy to identify repetitive actions and areas that significantly increase the time it takes to complete certain operations.
Spaghetti diagrams are one of the tools used in lean manufacturing. Earlier we talked about lean project management. It is based on the same principles as lean production.
As many operations are repeated, the worker’s movements on the map are also duplicated. If you observe the work for a long time, the resulting scheme (diagram) will visually resemble a plate of spaghetti: partly intertwined, partly repeating, partly crossing strips (lines, tracks).
In fact, this is where the name of the diagram comes from — spaghetti.
Most interestingly, the diagram can be used not only to visualise the movement of people, but also to visualise the movement of goods (in the warehouse, on the shop floor, between different departments), work pieces (between different sections of the production line), delivery batches (relevant to logistics), documents and even business processes.
For this reason, spaghetti diagrams are actively used in the management of people, companies and production processes.
What the spaghetti diagram allows you to do
It can visualise almost any pattern of motion. And the motion does not always have to be a complete miniature of the physical world. They can easily be logical and virtual schemes of connections between separate main elements.
But yes, the spaghetti format works best with real movements of physical objects: people, goods, cargo flows, workpieces, etc.
Using spaghetti diagrams you can
- Count the number of operations performed by an employee in a unit of time (it can be a working day, an hour, a week, depending on the complexity and repetitiveness of individual actions — work cycles).
- Identify the most repetitive and important activities.
- Identify bottlenecks that may limit or slow down other operations.
- Evaluate the workload and productivity of individual workers.
- Optimise work cycles and movements by simulating situations with shorter distances and better positioned work areas.
- Reduce the space required for all work activities.
- Increase labour productivity and free up additional working time.
How to build a spaghetti diagram
- To make a diagram, take a plain sheet of paper and draw the location of all the main work areas. They can be labelled pictorially (schematically) or drawn to scale (for greater accuracy).
- The next step is to observe the worker’s actions and movements and draw them in sequence on the diagram.
- The observation time should be at least one hour. However, it all depends on the nature and complexity of the workflow. The greatest reliability of the diagram can be achieved when the operations are plotted over a period of about 20 work cycles.
- You can indicate the direction of movement (e.g. with arrows) on the movement paths.
- If an employee spends additional time in each zone, e.g. to perform an operation or to find a necessary tool, it is possible to make appropriate notes on the work zones themselves (inside or next to them).
- It is logical to exclude breaks or time away from the workstation that is not directly related to the work task from the total time you observe the employee’s actions.
Once the allotted observation time has elapsed (or at least 20 cycles have been repeated), the graph is ready for analysis.
Obviously, the longer the observation time and the more cycles repeated, the more reliable the result. However, in the case of a spaghetti chart, this can have the opposite effect — the chart may become unreadable at some point.
Or you may need to use special software to compile and display the data.
Don’t forget that direct observation of all processes is important. This will enable you to identify all the main problems and pitfalls in the work processes.
Where spaghetti diagrams are used
Spaghetti diagrams can be most effective when analysing work processes on production lines.
However, this does not mean that such charts cannot be used for other management and administrative tasks. Spaghetti diagrams can be used in the following cases:
- Logistics. Evaluate the performance of the supply chain and optimise the route map.
- Production. Movement and storage of consumables, spare parts, inventory. Optimisation of work processes and operator workstations.
- Classic management. Estimation of labour productivity to obtain an ideal working time benchmark. Evaluate the work efficiency of employees (by number of operations or products per hour), plan workloads, estimate work completion time, etc.
- Project management. Similar to traditional management, but the emphasis is on workload estimation and time planning.
Information flows and business processes. Building information exchange schemes and identifying key nodes, optimising or duplicating bottlenecks, parallelizing processes.
What type of loss does the spaghetti diagram identify?
The spaghetti diagram allows you to evaluate the following key parameters:
- time,
- distance (path) travelled by the object of assessment.
Time and distance are closely related. By reducing the distances travelled by an employee (a product, an item on the production line, a message on the email line, etc.), you reduce the total time spent working.
The time freed up can either be used for additional work, to shorten the working day or for other purposes. Either way, it’s cost optimisation.
And reducing losses and costs is the goal of any business. After all, it increases the amount of profit.
Important nuances
When making spaghetti diagrams, remember that the diagram itself is not a finished analysis. It is only the basis for carrying it out.
In other words, drawing a spaghetti diagram will not optimise the process. It will require a lot of modelling of the situations in which that improvement will be possible. You also need to be realistic about the financial cost and payback of the changes. For example, if you have to move a conveyor line from one building to another to reduce the distance people have to walk, it is likely to be unreasonably expensive. It will be much more efficient to reduce the journey time by other means: an additional transport line, loading transport, etc.
To avoid such situations occurring in the course of work, it is logical to model the actions and movements of people from the outset, even before the construction and commissioning of your production facilities.
The key to the success of any project is good planning. And to make sure nothing is forgotten or overlooked, we recommend using dedicated BPM systems rather than writing plans on scraps of paper or in notebooks. Be professional from the start, not later.
