One of the central pillars to lean manufacturing is minimizing waste. The original Toyota Production System, which outlined the basics of Lean Manufacturing, highlighted seven lean wastes:
Many people also add an eighth waste: unused potential. Here’s a closer look at how you can reduce the eight lean wastes.
One of the most common examples of transportation waste is excessive walking distances in warehouses. As much as 50% of the picking process goes to travel in many facilities. Since walking accounts for so much waste, you can significantly improve productivity by shortening distances.
Reorganize workflows so that the most frequently needed items take the least amount of time to get. Diagraming all movement within a facility can reveal where there’s too much travel, showing where to reorganize. Creating a U-shaped production line will also help, as it enables a smoother flow between stations and reduces how far workers have to move.
Anywhere from 20 to 30% of inventory in a company is either dead or obsolete. Analyze your workflows carefully to see how much of every item or material you use, then order only what you need. This just-in-time approach to inventory will clear space, reducing waste you may not have realized you had.
Just-in-time inventory comes with some risks, so it’s crucial to reassess your needs continually. Keep an eye on changing trends and use demand forecasting to ensure you always order enough materials without ordering too much. Removing buffers between production steps can also help reduce inventory.
Reducing motion waste means reducing walking, lifting, reaching, bending, and stretching as much as possible. One of the most straightforward ways to do this is to place everything a worker needs within arm’s reach at their station. This will save time between steps and prevent lost time due to repetitive stress injuries.
Another effective solution here is to turn to machinery. For example, lift tables reduce manual work in palletizing by removing the need to reach, bend and stretch. Automation can produce similar effects, performing motion-heavy tasks like lifting and carrying so workers don’t have to.
Most of the time, instances of this type of lean waste aren’t intentional but come from improper timing. Just-in-time orders and manufacturing help reduce bottlenecks, but you can take further action too. Steps to minimize transportation, like U-shaped production lines, will also decrease waiting times.
Standardizing methods across the entire workflow can help ensure consistency, preventing pauses and delays. You should also distribute workloads evenly across processes to facilitate this. Another, often overlooked, solution is to put more effort into employee training. More highly trained, skilled workers will work faster and more consistently.
Overproduction is especially relevant for the food industry, where 51% of total waste comes from overproduction. Waste from overproduction becomes inventory waste, so addressing this area mitigates two problems at once. Like with inventory waste, the solution here lies with data and just-in-time processes.
Keep a close eye on consumer demands to produce only what will sell. Working in smaller batches can enable greater flexibility, helping you match changing demands more efficiently. Using a pull system helps control the amount of work in progress, making it easier to limit production and prevent surplus.
The sixth form of lean waste, overprocessing, occurs when you do anything that doesn’t add value to the end product. Analyze your workflows and, for every step, list the benefits it brings to customers. If you have trouble thinking of this for any processes, remove them.
Overprocessing often appears when you change a process, rendering one step unnecessary without realizing it. With that in mind, every time you make a change, reanalyze the workflow. If there’s something that’s no longer necessary, remove it. Like many other waste areas, this will change over time, requiring ongoing analysis and improvement.
Defects are perhaps the easiest to quantify of all the lean waste categories but not always the easiest to prevent. Final quality checks stop defective products from getting to customers, but they don’t prevent waste. To eliminate defects, you need to determine their source.
Look for commonalities between defects. You can then track them back to a specific part of the process and amend it to prevent them from happening. Quality checks throughout the process instead of at the end can help fix potential issues before they lead to noticeable defects. Standardization and more thorough training will also help here.
- Unused Potential
Unused potential is one of the most overlooked areas of lean waste. Surveys show that 37% of employees say that personal recognition would encourage them to produce higher-quality work more often. That also means that if you’re not recognizing and encouraging employees for their work, they’re not reaching their full potential.
Highlighting and praising workers’ talents and work in the business can push them to work better. Similarly, you should encourage suggestions from employees, since they’re often experts in their positions. Workers may find inefficiencies or ways to improve you would’ve missed otherwise. Set up a reward system for effective changes that result from employee suggestions.
Reduce All 8 Forms of Lean Waste
Even the most efficient company has waste, and they likely don’t realize its full extent. Understanding the eight forms of lean waste is the first step to reducing them.
The specifics of how waste reduction plays out in each facility will vary, but the underlying principles remain the same. Take these suggestions, see how they apply to your processes, and start becoming a leaner, more agile business.