Learning Objectives
By the end of this section, students will be able to:
- Describe potential ways in which AM can improve sustainability in manufacturing.
- Describe potential ways in which AM can improve sustainability in product usage.
There are less-tangible and perhaps less-quantifiable benefits of additive manufacturing as it relates to the supply chain, work in progress, inventory and sustainability. We will again use our maturity model as the framework for this discussion.
AM is generally considered to be sustainable because of the following reasons.
- Less waste because of the nature of the additive process, unlike parts that are stamped or sculpted out of a larger piece of material
- No specialized tooling or fixtures required for AM
- Can build functionally light weight parts, while maintaining strength that reduce energy consumption while the part is in service
- Reduces the need for large amounts of raw material within the supply chain and transportation
- Largely material-efficient when compared with traditional machining and casting
- Can produce optimized geometries with near-perfect (compared with wrought material) strength-to-weight ratios
- Less impact of the part over its life cycle, resulting in a lower carbon footprint, less embodied energy, and better economic model
- Can create on-demand spare parts, reducing or eliminating inventory
- Can produce complex parts with reduced peak stress or high-corrosion areas that will require fewer replacements in the lifecycle of a system or facility
In the following sections, the Maturity Model will be used as a reference for the product and the Supply Chain, Inventory and Sustainability benefits of AM will be described.
Level 0
Supply Chain
At level zero, organizations are flexing the first elements of the AM supply chain to understand what is possible. They need to understand the AM supply chain and that begins to reduce risk.
Work In Process and Inventory
If they can use AM for prototypes, they are likely to have less Work in Process (WIP) and less need for inventory. AM printers become the tools used, and they are not fixed to a special part or part number necessarily.
Reductions in both inventory and WIP are possible at Level 0.
Sustainability
The use of AM promotes more efficient use of materials in the first instance. First products typically use materials very inefficiently to show product viability first and foremost. Avoiding fixed tooling can then be another benefit when in product design, the final geometry is likely to change based on test feedback which means more tooling may be required.
Level 1
Supply Chain
At level one, companies are reinforcing supply chain benefits through temporary or flexible tooling and fixtures. The supply chain can become less complex because the organization is agile and flexible and can print on demand.
Work In Process and Inventory
WIP is reduced on one hand through tooling minimization and less tooling. Shop fixtures and jigs may add some complexity but are generally low value and pay for themselves. In general, trackable inventory of tools should decrease.
Reductions in both inventory and WIP are possible at Level 1.
Sustainability
Producing fixtures and shop aids promotes less time re-working parts and better productivity through a reduction in injuries from repetitive tasks. Where fixed tooling comes into the picture, companies can use processes like casting for shorter runs because the tooling is easier and cheaper to make, thus making use of existing assets. The case for material efficiency is the strongest.
Level 2
Supply Chain
At level two, organizations are dynamically exercising the a new supply chain, and maintaining schedule is very important to maintain cost efficiency. At this stage, the organization is learning and reducing risk.
Work In Process and Inventory
Companies are likely to have less WIP and less inventory at level two because they are putting most of the effort in the printing process. AM printers can be used to make more than 1-part number.
Sustainability
AM will drive the more efficient use of materials. It is likely that companies are reducing the overall path of the part and therefore reducing carbon emissions to move the part from one location to another.
Level 3
Supply Chain
At level three, the supply chain is compressing as the company reduces part count and process steps.
Work In Process and Inventory
The company has fewer parts and therefore less inventory. Because it has reduced process steps, the company may also have less tooling and WIP.
Reductions in both inventory and WIP are expected at Level 3.
Sustainability
AM begins to make an major impact on sustainability at Level 3. Using more efficient use of materials is a start. Less energy is consumed because they are are making fewer parts. Unitizing also then enables savings in emissions moving and shipping them around by consolidating the supply chain. It also makes an impact on reducing the weight or increasing the efficiency of the overall system.
Level 4
Supply Chain
At level 4, the company has largely optimized the supply chain around AM. The process is much leaner and exhibits the 90% learning curve mentioned earlier.
Work In Process and Inventory
The company has consolidated parts and processes so WIP and Inventory are optimized for financial performance.
Sustainability
The AM solution has higher performance or is enabling better performance of the system it is in. It has all of the benefits of Level 3. It helps the system perform better, which itself could reduce energy consumption.