Lean Tool
SPAGHETTI DIAGRAM
LEAN TOOLS
Spaghetti Diagram
Description of Spaghetti Diagram
A flow charting method that uses a continuous line to trace the path of a part through all phases of workplace. Spaghetti diagrams expose inefficient layouts and large distances traveled between steps.This is a visual representation by drawing a line from one place to the next. It records all the back and forth and extra steps.
Spaghetti Diagram is appropriately named as a complex process that maps movement looks like a plate of spaghetti.
It helps to reveal opportunities to reduce or eliminate the steps and time associated with certain activities such as movement of materials or information. It's amazing the number of excess steps it takes to accomplish a particular activity in our day-to-day lives at homeor at work. This technique is extremely useful when watching people in a plant perform activities within their scope of work, or tracking the movement of product. By tracing and analyzing their steps you will discover potential improvements that will help employees work “smarter” and accomplish more in less time.
When to use the Spaghetti Diagram
The Spaghetti diagram can be used at any time to gain clarity and understanding of currentcondition. In general, the Spaghetti diagram is best used when current condition needs to be moved to animproved future state.
Creating a spaghetti diagram is the visual creation of actual flow. The keyword is ACTUAL, not what it should be or perceived to be. It is a snapshot in time so it may not include all what-if and special scenarios, but these do warrant discussion as the team progresses.
Spaghetti diagram is sketched and used to track:
Product Flow
Paper Flow
People Flow
Excess walking or transport time, complex processes
‘Before and after’ evaluation of the existence of waste
How to use the Spaghetti Diagram
This is not an exercise to do on a computer at a desk.
Use a different line type or color for each flow type, or use separate map for each flow path for more clarity.Creating a Spaghetti Diagram should be done with or by the operators or those that use the process. Record the path with a pencil and use a measuring wheel or tape measure to document distances. You are looking for "cooked spaghetti", not spaghetti directly from the box, things rarely move in straight lines.
Items needed to get started:
Actual Process, overhead views of area, drawn close to scale and labeled
Colored Pencils
Measuring Wheel and/or tape measure
Stop Watch
Team, Operators, People impacted by the flow
Steps to create diagram:
- Record the processes on the side and ask questions if not clear on the activity.
- Start at the beginning of the scope, the start of the first process. Use directional
arrows for the routes that are traced on the paper.
- Do not leave out any flow movement even if the paper becomes cluttered and
difficult to follow. This probably indicates opportunity. Most often, the perceived
unusual flows, or “exceptions”, are actually happening more often that is realized.
Capture these!
- Record the amount of time at each activity.
- Shows the areas where materials stops, staged, held, inspected and picked up. Look for point-of-use opportunities for materials, tools, and paperwork.
- Record the names of those involved,dates, times, and other relevant information.
- Calculate the distance, times, shift, starts, stops, to provide baseline performance.
- Create a separate diagram showing the ideal state of flow for each that eliminates as much non-value add tasks as possible. The team should target
the ideal state and the Project Manager and Champion should remove obstacles that may prevent this objective.
It may take several iterations before the final layout is determined.Ideas will be generated as changes are being done and results will vary. Execute as many of these changes with little cost and the best quality possible.
Some items may require capital investment and upper management approval. These should be investigated and submitted if justifiable. Make a note of these outstanding action items with timelines to the Gantt Chartor project checklist but don't allow them to stall progress.
Put the open action items on an easel or board in the specific area and keep it visible for everyone to see. It is also a good idea to audit the changes, especially until new habits are embedded and the culture is engrained.
Tips on use of Spaghetti Diagram
Do welcome volunteers
Do explain the purpose and demonstrate the process
Do assign roles
Do check for understanding
Do find an alternate way for a volunteer to help if they aren’t comfortable
Do simplify the process so it can be learned quickly
Don’t forget to check in to see how they are doing
Ensure process boundaries and/or work area is clearly defined
If studying more than one individual or material moving through a process,
use different colors to represent parallel flows.
A pedometer may be used to measure the number of steps taken
Prepare materials:
• White board, paper or blackboard large enough to document motion
• Appropriate writing utensils
Visit and study the area where process is executed; understand process.
Circle diagrams are similar to spaghetti diagrams and are used to map handoffs
of information. The technique is similar but instead of drawing a floor plan, asimple circle is drawn to represent the process.
Different colors can be used to denote different people orparallel processes.
Resist the temptation to redesign workstations, flows or policies without team
input; ensure team includes those working in the area as well as immediate supervisors or managers.
Applicationsof Spaghetti Diagram
Biology
Business
Medicine
Administration
Manufacturing
Services
Examples
1.The following spaghetti diagram shows the number and distance “Engineering Change Orders” went through during the time of observation.
Before Improvement Diagram
After Improvement Diagram
2.Operator Flow
Before Improvement Diagram
IDEAS to IMPROVE
After Improvement Diagram
References
- The Lean Six SIGMA Pocket Toolbook: A Quick Reference Guide to 70 Tools
byMichael L. George.
- Implementing Six Sigma: Smarter Solutions Using Statistical MethodsbyForrest W. Breyfogle III
- Practical Quality by Graham Ross
- Beyond the theory of constraints: by William A. Levinson (2007).
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