Although it may seem intuitive for lean manufacturing and green manufacturing to go hand in hand—after all, both aim to make manufacturing processes more efficient and less wasteful—for many manufacturers, this isn’t always the case. Some actions a company takes in “going green” may be met by working towards certifications like ISO 14001. Other companies may forgo these efforts and focus solely on “going lean”—although, this is not always the case. In the chance that a manufacturer is committed to going lean, more often than not, “going lean” means working to avoid the “seven types of waste”.
Before looking at going green, let’s take a look at the classical “seven types of waste” that lean manufacturing aims to minimize. They are as follows:
- Defects and errors
- Inefficient processes
- Excess inventory
- Wasted motion and movement
- Excessive material handling.
Although the process of avoiding these types of waste may be primarily linked to lean manufacturing, doing so can likewise yield positive green impacts too.
When it comes to medical device manufacturing plants–plants that tend to be clean and very well-organized to begin with–there are a multitude of opportunities for factories to combine lean and green strategies when reducing waste.
Consider material flow beyond manufacturing materials
Reducing inventory is a classic lean manufacturing method. Through this approach, a factory is forced to develop smarter material flow techniques across all aspects of their production. Manufacturers will often use their inventory as a way of measuring their lean success for this very reason. Inventory is a crucial metric for financial performance, so it only makes sense to further look to inventory data as a measurement for lean manufacturing. However, factories could also do well to consider the green benefits of inventory reduction.
If the amount of inventory moving in and out of a warehouse is reduced or if travel pathways between production processes are streamlined, it usually goes that the amount of energy used to transport inventory will also be reduced. This holds especially true when talking about the use of forklifts. More specifically, the costs associated with operating the forklifts, the emissions produced from them, and the electricity used to charge forklift batteries would all be reduced, and as such, both lean and green waste reduction objectives would be satisfied
The green perspective should also be carefully considered when working to create strategies to improve material flow. For example, let’s say a manufacturer is working on reducing the travel distance of inventory between assembly work cells. Methods for handling this may involve the use of material carts, gravity-feed conveyors, line-side flow racks, or other types of tools used for replenishing inventory. In order to consider green thinking, a manufacturer should ask themselves what type of material should be used to build these tools in order to improve greenness alongside leanness.
The material of such tools is incredibly important for medical device manufacturers, especially given that innovation is rapid and flexibility is key if manufacturers are to keep up with ever-evolving customer demand. If demand requires the adaptation of tooling, factories must consider the environmental impact of doing so. For example, welded stainless steel systems are expensive, intensive to build, and difficult to re-purpose. Aluminum bolt-together systems would be an excellent alternative, because they allow workstations to be easily disassembled and reconfigured with less wasted material. Both lean and green aims are satisfied when firms look outside inventory material flow in this way and also consider material flow of all aspects of their production.
Pros and cons of automation for lean and green manufacturing
Automation is often questioned as a technique that aligns with lean strategies. For starters, energy used for automation is often significantly wasted. Plus, it may not be able to offer the flexibility that human labor can. However, when it comes to medical device manufacturing, automation can provide a level of precision which is absolutely essential for successful manufacturing. When dealing with intricate parts or sensitive electronics, automation can provide greater control, which leads to better quality yields and less waste. Automation is therefore a key aspect of lean manufacturing for medical device manufacturers.
That doesn’t mean to say that automation shouldn’t be considered in lean and green strategies for medical device producers, as there’s still the issue of excessive energy use. In order to reduce energy waste, many automation suppliers are developing technologies that allow systems to use energy more efficiently. They are also creating methods for performing energy audits of existing automated systems and using the information to inform manufacturers of methods for saving energy. Although there is no quick, affordable fix for excessive automation energy use, manufacturers can and should be doing what they can to prevent it.
Achieving balance with pneumatics
Compressed air is widely used in manufacturing worldwide given its ability to power a huge range of activities. From routing and handling on conveyor belts with pneumatic systems, to manually assembling parts with pneumatic screwdrivers, compressed air is an essential aspect of manufacturing. When it comes to medical devices, the use of pneumatics is often highly specialized to ensure that the handling of sensitive components is gentle, to maintain high levels of cleanliness, or to even aid in the assembly of minute parts within very compact devices.
Energy costs can account for over 50 percent of the total costs of owning pneumatics. So for manufacturers eager to become leaner and greener, a careful assessment of pneumatic usage is essential to minimizing waste. Pressures should be optimized and dead volumes avoided, and in order to do this, manufacturers must consider three key aspects of pneumatics: dimensioning, hose length and pressure regulation.
- DimensioningAlthough some manufacturers may be guilty of the “more is more” attitude when it comes to dimensioning pneumatic components, over-dimensioning can cause wastefully high rates of air consumption. Sometimes manufacturers will add this extra capacity in case their requirements ever change, but it’s possible to save an impressive 15 percent of air volume by using smaller valves and cylinders designed for actual requirements. The key is to create pneumatic systems which serve current needs. This way, significant waste reduction can be made.
- Hose lengthsAlthough it may seem more convenient to create centralized systems to deliver compressed air, it can result in huge amounts of waste. This is because they require longer hose connections to reach application areas, meaning that more volume must be filled and more air must be used. By decentralizing systems to the site of application, many airlines can be completely removed, hose lengths can shortened, and energy usage can be reduced by up to 30 percent. Another added bonus is that pressure losses that are common with long supply lines are also minimized.
- Pressure regulationOnly using as much pressure as is needed is essential to minimizing energy waste, but for some manufacturers who have leaky compressed air systems and unpredictable pressure, it is tempting to amp up the pressure to compensate. Investing in the latest technology, which combines proportional technology with digital control electronics to enable intelligent pressure control, can be a sound choice for those looking to become lean and green. These sophisticated systems are designed to constantly compare actual value against the specified value in order to maintain exact metering. By providing the right pressure for each individual task, it’s possible to reduce energy use by 25 percent, which is a significant saving.
Looking at the small details in assembly and automation
Although the lean and green strategies we’ve explored so far have been relatively large scale, there are many ways in which manufacturers can make small adaptations which all add up to big impacts on waste. In the medical device industry, Multiaxis Cartesian robotics systems are commonly used during automated assembly and laboratory processes. It is possible to carefully optimize these robotic systems to become leaner and greener.
LOSTPED, or Load, Orientation, Speed, Travel, Precision, Environment and Duty, is a method for optimizing a robotics system’s design by trading off different factors of its functionality to achieve the most efficient and cost-effective system possible.
In the medical industry, load and precision are commonly traded off, so let’s use these factors as an example. During medical device assembly, most loads which need to be lifted, moved, and positioned in place will not be very heavy. This means that it could be possible to use lighter actuators to carry the loads. As a result, less combined weight will be moved across the entire movement, which will save energy. If, however, high precision is crucial, the weight of the actuator should not be made too light; this could result in loss of control and reduced precision. The consequence of this would be poorer quality devices and more waste. By balancing off load and precision carefully, though, it’s possible to optimize the system to reduce energy consumption while maintaining high quality levels.
LOSTPED is designed to allow manufacturers to weigh up a wide variety of factors and trade-offs which, alone, may result in smaller amounts of energy savings, but together will contribute towards significant savings each and every day. Not only does this make manufacturers greener and leaner, but it also gives the bottom line a boost.
Lean strategies are green, and green strategies are lean
Although lean initiatives are top priority for medical device manufacturers in the United States, green initiatives don’t have to take a step back. Recently, energy costs have been relatively low in the US, which has made going green less of a priority than in other areas of the world. However, by looking at strategies with a green perspective, it is possible for factories to find even more waste-reduction initiatives that simultaneously support lean manufacturing.
Lean and green go hand in hand, each one complementing the other; and by looking at both, manufacturers could begin to see more substantial results to their bottom line.