Sometimes increasing production throughput can be as simple as rearranging your production shop floor. In fact, when it comes to lowering production cycle times, few approaches are as powerful as using spaghetti diagrams.
You'll need your production employees to work alongside you for this project as their input is essential to success.
This staple of Six Sigma and lean manufacturing allows you to redesign your layout so that you’re minimizing transit times between work cells. Lower those times and you’ll increase throughput.
So, what does it take to make this all-important and simple tool work? Well, most of the heavy lifting will be done if you need to redesign your shop floor. However, you won't know that until you've completed this exercise.
It involves you bringing together all your production employees so that they understand what you’re doing, why you’re doing it and how they can help make it a successful project.
Ultimately, it's an investment on your part, one where you define your current layout and all its flaws. You then quantify delays in a way that speaks to why a redesign is needed. To help, here is a five step approach to making this work.
1. Make Your Employees Part of the Process
Don’t leave this open to interpretation. Be transparent and straightforward with all your production employees. Start by explaining how this exercise will simplify how they work and reduce the time it takes to move semi-finished inventory from one cell to the next. Ask for their input and suggestions.
2. Map Out Your Existing Layout
It’s important that you map your layout as it is, flaws and all. Clearly distinguish where each individual work station is located in addition to the locations for inventory, quality control (QC) and inspection, and any beams or pillars within the various work places.
Do not ignore these aforementioned obstructions. Beams and pillars are commonplace but your spaghetti diagrams must show how work has to move around these stationary roadblocks. This is ultimately why they are called “spaghetti diagrams’ as the lines show how work actually flows. The idea is to define how raw materials become finished goods by outlining each step they take in the process.
3. Define Workflow
Use sequential numbers to define the flow of work. This means accounting for where raw materials and semi-finished goods move across your shop floor. Make sure the flow of work is agreed-upon by your production employees. Next, finish the process with a continuous line connecting each sequential number.
4. Record Distance and Time Traveled
Use a measuring wheel that tracks the distance traveled in feet from one cell to the next. In addition, keep track of how long it takes to move between these cells. This will involve multiple samples where you take note of any work-related delays, issues and lost time. You want as large a sample portion as possible.
This is ultimately why they are called spaghetti diagrams. The more samples you take the better your analysis.
5. Define Existing Transit Times and Total Distance Traveled
This entire exercise becomes beneficial once you’ve totaled up all the distance and travel times. The table to the left outlines how such an analysis might unfold. The batch size is 100 units and the company produces 600 units in an eight hour shift.
They've used the measuring wheel in order to capture the distance traveled and have taken an average transit time between each process step. Again, the focus is on taking several sample portions in order to get a clear indication of the transit times in seconds.
Essentially, every batch of 100 units travels a total of 743 feet. This is then multiplied by six which is the number of batches produced in an eight hour shift. This new total of 4458 feet is then multiplied by five business days in the week in order to give us 22,290 feet.
Next, the transit times are totaled. A single batch of 100 units takes 4.08 minutes to move across the shop floor. This is then multiplied by six again, which gives us 24.48 minutes of total transit time for six batches. Over a period of one week, the total is 122.4 minutes of travel time or a little over 2 hours.
Now, this is merely an example. It’s more than likely that both the distance traveled and the transit times are much higher. However, the purpose is to show how critical this exercise truly is.
Bring your production employees together and ask for their guidance on this project. It will make a difference. Now, will reducing the travel times by having a better layout help you increase production throughput? It most certainly will.
If you want to read about how to properly design work cells, then please go to the following posts:
