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No, the real benefit of additive manufacturing (AM) is not speed. Although speed can be advantageous, it is only a feature of AM that translates to a benefit when a lead time reduction produces results. The real benefit of AM is efficiency, a measure that considers speed, effort, process delays, process steps and personnel time.
Efficiency is the fundamental advantage of AM, and it is not proportional to the three characteristics that are exhibited by the strongest AM applications. Unlike any other process, AM retains its efficiency when production volumes are low, complexity is high and changes are frequent. Together, these four elements comprise the four pillars for ideal AM applications.
These are the four things that you should always keep in mind as you are rationalizing or justifying the use of AM. And these are the four characteristics to have in the forefront of your mind as you look for ways to expand the use and grow the value of AM within your organization.
It is a bit controversial to boldly state that speed is not a primary benefit of AM, but it is true.
Since the dawn of the rapid prototyping age, suppliers have touted AM’s ability to reduce time to market. While that is a powerful advantage, one that could result from accelerated product design, product testing or production, it is only possible if AM accelerates the bottleneck operation.
If you are unconvinced, read the manufacturing classic “The Goal” by Dr. Eliyahu M. Goldratt, a business consultant whose Theory of Constraints has become a model for systems management. In his fictional account, Goldratt clearly shows that there is little or no advantage in improving process speed before or after a bottleneck operation. Speeding up the upstream process just puts more work in the queue. Speeding up the downstream process increases the time that it sits idle waiting for work.
Considering this logic, speed is a benefit of AM only if the function it performs is the bottleneck. For example, if AM prototypes arrive weeks before electronic assemblies, the electronics throttle functional testing. The result: no decrease in time to market.
However, under the umbrella of efficiency, the benefits of task time reduction and responsiveness remain even if processes are not accelerated.
Shift in Goals
About six years ago, I angered Z Corp. management during my keynote at its annual users group meeting. In the first 30 seconds of my presentation, I told the audience to forget about speed…to forget about the “rapid” piece of rapid prototyping…which was, and still is, a major differentiator for this 3D printing process.
The anger and anxiety subsided as I clarified my statement. As I’ve already stated, the benefit is efficiency. Moreover, raw speed only becomes an advantage when you do something beneficial with the process acceleration. One example offered was conducting more design revisions in a set time span.
Even further back, I published a companion piece to the presentation I was to do at one of the early TCT conferences. I didn’t know it then, but I was making the case for the four pillars of AM’s advantages. Blended in with efficiency were the benefits of AM that catered to human nature, items such as tactility and procrastination.
The goal of that document was to turn the focus to personal and departmental gains rather than corporate results. That remains the fundamental intent of the four pillars. People change their ways when they are forced to (management initiative), have to (problem solving) or want to (easier for them). The four pillars accommodate each scenario.
Yes, you need to have corporate gains to use AM, but these will follow. Making the process more efficient will translate to measurable results in the departmental budget and corporate ledgers.
I am quite pleased that this message is coming back to me from industrial AM practitioners. I can’t take credit for the shift in philosophy, but I do find it rewarding that this mindset is taking hold.
Just this month, as I was conducting research for a white paper, three of four people that I interviewed overtly stated that AM is their go-to solution because of efficiency. The fourth implied it. These people stated “AM is a simple, quick, and affordable problem solving tool” and “AM is the path of least resistance.”
Versus any other tools or resources at their disposal, they told me that AM:
• Requires less effort on their part (e.g., documentation)
• Requires less upfront analysis and planning (e.g., no need to ask “can I” or “how”)
• Requires fewer steps (e.g., design, print and done)
• Requires fewer dedicated, highly skilled resources (e.g., toolpath creation)
The bonus is that AM is usually cheaper and faster than other methods when part quantities are low, complexity is high and revisions are frequent.
Realizing the efficiency advantage, these companies find that AM is an alternative, not a substitute. What happens is that they make objects with AM that they otherwise would not. Therefore, they are putting more models, prototypes, tools and parts into service than they would if they followed the conventional route.
In the cases where they would approach the project through conventional means, they find that AM is an alternative with unmatched advantages when making just a few complex parts or making frequent changes.
Applied to real problems and opportunities — as opposed to using AM just for frivolous endeavors — everyone wins. The individual responsible for the project or task implements a solution with much less effort. The company realizes increased process efficiency, decreased expenses, shorter timelines and better product designs. All of which will show up on the corporate profit & loss (P&L) statement.
Now that I have made the case for the four pillars, let’s look at each individually.
According to Dictionary.com, efficiency is “accomplishment of or ability to accomplish a job with a minimum expenditure of time and effort.” This is what AM offers for part-making and tool-building when extensive postprocessing and secondary operations are not needed.
What efficiency does for AM is alter the input|output equation. With less time and effort invested (input), the action is more easily justified.
Admit it, the harder something is to do, the less likely you are to do it.
AM makes part making a simple task rather than an involved project. So, we are more likely to make what we need, as frequently as we need it. In the concept phase, for example, this means that designers will be more likely to make multiple models from multiple design revisions when using AM. That same logic carries through to mechanical design and manufacturing.
The high efficiency remains even when making parts in extremely low volumes and for a single instance. This is counter to mass production, where efficiencies are gained with large lot sizes and long runs. It is also counter to everyday tasks where repetition increases efficiency.
Considering throughput, AM is most advantageous when quantities are low — as low as a one-off, bespoke product.
For any conventional fabrication process, high design complexity decreases efficiency (and increases cost). AM, on the other hand, has no link to complexity, and therefore, complexity does not diminish efficiency.
While part complexity is not a requirement for AM, it does increase its advantages. So, AM becomes a preferred alternative as complexity grows.
Frequent changes and multiple revisions are inherently inefficient, and to be avoided, when machining, molding and casting. With AM, they are encouraged.
With only a modification to the design, AM will efficiently reproduce 3D objects with no additional time and labor needed. So, the fourth pillar to build on is AM’s flexibility in accommodating frequent changes to address the problems and opportunities that arise.
Speed and lower costs may result from the application of AM to design and manufacturing applications, but the unmatched benefits are the combination of efficiency with low-volume, high-complexity, and ever-changing parts.
This is the fundamental value proposition of additive manufacturing. Keep these real benefits in mind as you go about your daily duties, and you will find more applications for the technology — applications with real benefits to your department, division and corporation.