Q. 177  Explain a spaghetti diagram and its use.

 

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A Spaghetti diagram is a visual representation of actual flow in a process, system or natural stream. It is used to understand the transportation, waiting time and motion and is applied in sevaral industries such healthcase, factories, meterologyand others to understand, optimize or improve efficiency in the process, system or natural stream.

Spaghetti Diagram is one of the Lean Tools. Lean manufacturing focusses on continuous  elimination of Waste. There are eight types of Waste as per the Toyota Production System. These eight types of Wastes are as mentioned below

1)      Unnecessary Transportation

2)      Excess Inventory

3)      Unnecessary movement

4)      Waiting

5)      Over processing

6)      Overproduction

7)      Defects

8)      Unused employee creativity.  

 Spaghetti diagram is used for tracing   the movement of materials, men & even documents for the sequence of operations / process under study. The diagram shows the physical  distance travelled form one workstation to another. Generally, lot of to & fro movement or even zig zag movement is observed in most of the processes. All such to & fro or zig zag movement is a Waste -Unnecessary movement which increases the cycle time or throughput time thereby contributing towards increase in the cost. The diagram looks a Spaghetti & hence known as Spaghetti Diagram.

For drawing a spaghetti diagram, one can use a blank sheet of paper. On this sheet one needs to first draw the existing layout of plant & machinery, workstation etc. Next draw the line charting the movement/ flow  of materials, men or document based on the scope of study. Note down the distance travelled on this chart. Different colors can be used to trace the movements (of different types of materials / document / men – as the case may be). On a single paper one can draw as many movements as possible. The only limitation is that the diagram should be  legible. 

The  reasons for spaghetti movement are as follows.

1)      Improper  plant / office layout.

2)      Sometimes the initial layout is made scientifically based on Work study & ergonomics but later on additional operations are introduced or sometimes new equipment is   added, thereby resulting into   spaghetti movement.

Thus, Spaghetti diagram helps in identifying unnecessary movements (one of the eight types of Waste) thereby providing an opportunity to make the process Leaner/ more efficient.  

       

Spaghetti diagram is one of the visual representation tool that is used for measuring the distance traveled by  material & man movements as per process flow in plant layouts. The name is coined because of the appearance of man and material flows like Noodles in practical. 

 

It is a very useful to calculate the impact of two Lean wastage - Transportation( Material from one work station to other by means of manual, semi automatic or automatic) and also human Motion - in-effective Therbligs (as per Gilberth's Motion & time study) which refers operator VA/NVA - Pick & Place/Load & unload/ Grasp& release in performing a job in prescribed method.

 

The actual benefit of Spaghetti diagram is resulting the optimization of layout in minimal space & creating shorter distance traveled by material & man and this directly leads to enhancing the throughput with minimal inventory.

 

In similar to Spaghetti Diagram,  other Industrial Engineering tools like Travel chart, SIMO chart, String Diagram  are widely used for process flow analysis based on the product/ process matrix & type of layout adopted.

Spaghetti Diagram: is a visual tool to help understand and trace the movement of people and/or material and helps in identification and improvement of the shop floor layout. It helps in visualizing two out of the eight wastes - Transportation and Motion. After studying the spaghetti diagram the unnecessary movements could be curtailed leading to an efficient process.

 

I have never used a Spaghetti Diagram, however, I feel it has usage in the following aspects

1. Designing the most efficient layout of the shop floor

2. Designing the layout of any service organization where customers are required to move. E.g. Bank, Hospital, Super Market, Passport Seva Kendra etc.

3. Designing the optimal route for a delivery boy. E.g. postman, Swiggy or Amazon or any other delivery boys or girls

4. Designing the optimal route for transportation. E.g. bus or cab routes for offices and schools

5. Providing a snapshot view of the route taken or the pre-defined routes. E.g. Map of the route taken post an Uber ride or the route map of an airlines or the map of metro coverage or routes of ships etc.

 

Providing some snapshots below to see how a spaghetti diagram looks like (images from Google search)

 

 

 

Fig. 1 - Optimizing the shop floor or customer service center layout

Fig. 2 - Route taken post an Uber ride

Fig. 3 - Domestic and International routes for an airline

Fig. 4 - Metro rail route map of Delhi

Fig.5 - World shipping routes (depending on the type of cargo)

Fig. 6 - Delivery route (may be planned or completed)

Spaghetti Diagram: Process Analysis tool
It provides lucidity and understanding of the workflow. It gives better clarity of the current process and allows to see the visual flow of process and helps us in identifying Areas of Improvement.

 

Without breaking the flow, continuous tracking in done to trace the flow of the activity in the process. It is used to track the ACTUAL flow of the process.

It is also referred as Point-Point Flow chart / Work Flow diagram or simple Spaghetti chart.

 

Below diagram on right, looks messy alike Spaghetti  and that's the name Spaghetti Diagram.

 

Quote

The most dangerous kind of waste is the waste we do not recognize - Shigeo

This powerful tool gives a sense of "Impact of Movement" in LEAN perspective and identify Wasteful Movements (Motion), waiting time and various transportation wastes in the process and keeps it nominal.

 

Usually used in complex process to understand the current flow "Current State - As-Is" and to propose opportunities for optimization "Future State - To-Be"

 

It can be used to track Product/Part, Multiple People/Person, Paper, Tools and Activity.

 

I would like to explain this with an example:

 

In the example, After lean - Spaghetti diagram (Improved Layout), considering below points:

• Activity distance travelled is reduced
• Distance is optimized
• People/processes relocated (Layout reorganized) to be in order in which the process flows or activities made close to each other (Better Sequencing)
• Unnecessary flow eliminated
• Waiting time reduced  
• Interruptions/facility constraints identified and eliminated
• KANBAN opportunities identified

                        >> This can lead to faster deliverables / delivery or

                        >> With no change in delivery time but with lesser effort put in to complete the activity

                        >> This could result in Space and Motion saving

Benefits of using Spaghetti Diagram:

• Helps to detect wasteful movements and identify ways to increase the speed of process
• Identify possible inefficiencies/bottlenecks/Critical paths which causes delay in work place layout
• Helps in creating ideal Layout design for the process  
• Recourse allocation improvement are also identified
• Unnecessary confused flow can be identified and eliminated
• It reduces Employee Fatigue and Improves Employee Morale
• It is used to identify redundancies in the process flow and eliminate them for optimal performance

A Spaghetti Diagram or Plot is a Lean Tool which helps in identification and thus reduction of waste.  It is easily defined as a visual graphical representation depicting a continuous flow of activities in a process.   
Although, spaghetti is not an in itself an optimization method, it is merely a tool for understanding the current representation of the process. 
The most ideal way of crafting a spaghetti diagram is by through walking through the steps of the activity. Plot the process on a piece of paper and jot down the waste items which have resulted in delays along the way. The ideal trick is to walk through the process physically to note the regularities and the waste. Since the items and steps are haphazard in nature, the final representation is messy and thus the name “Spaghetti”.

After a diagrammatic representation, it can used to determine a critical path solution for the process

 

It has several benefits for multiple industries as it identifies inefficiencies, wastes in motion and transportation, . The most optimum industries include manufacturing (factories), climatology, medicine and topography 
 

Spaghetti Diagram

 

Sphagetti diagram is visual representation of basic flow of people/product   

                OR

A visual creation of actual flow.

It is also known as workflow analysis diagram 

 

Steps to draw spahgetti

* It begins with layout of space where the flow takes place

* Then Record process on side and     start begining of scope.

* Need to check how frequently each place  is visited at workplace/production area

* Record amount of time within each   activity

* Need to understand distance ,time,Start stop ,execution area,

* Then record actual flow lines using pencil and paper to draw on space layout.

* When all flow lines are recorded they tend todraw spaghetti.

 

USES OF SPAGHETTI

* It shows layout of work place

* It helps to minimize the time of travel 

* It identifies inefficiency or unwanted  waste in process

* Avoid time consuming and nonproductiveactivities.

* Use to track product/people flow.

* Helps to make proper use of workplace  by organising flow as per process

 

 

 

It is actually the virtual way of presenting the working instructions to read them better. Every single step of the process is captured in the picture with the connecting dots in mind, from this diagram one can find out the time wasted in unwanted activities and can take measures to either eliminate or reduce these wastages

The chosen best answer is that of Mohamed Asif for providing clear answer, visuals and example. Read through Natwar, Sharad and Manjula's answers for more insights.