Design for manufacturing
is changing how companies approach medical device manufacturing. This is the
first of a three-part series about design for manufacturing and its effect on
different teams in the product development process.
Adopting a design for manufacturing (DFM) approach to
product design influences the work of each member of the product development
team. For best results, a systems perspective during the design phase is
critical.
All product designs start with the technical team. This
group typically includes research and development, design and engineering,
manufacturing, quality, and supplier quality. The team’s goal is to deliver an accurate,
measurable and manufacturable CAD model and drawings.
Metrology planning, manufacturing and post-processing are
three key methods to achieve this goal, and have a critical effect on DFM.
Metrology planning
Metrology planning defines how features will be measured and
why specific methods are chosen. There
are four key elements to have in place before any metrology planning session:
1.
A
fully defined CAD model
2.
Tolerance
analyses for all interfaces of the component and other components it touches
3.
Functional
map showing the other components and how the designed product effects them
4.
An
Excel file with each feature listed, including its nominal dimension and
tolerance
To
start this planning process, the full technical team reviews the CAD model and
works through the function of the component. This includes not only what the
product does, but also how it affects the components it touches. This analysis
should entail the datum reference schemes for each component and the associated
tolerance analysis justification.
Once
the team understands the design intent and datum reference scheme of the
component, it’s time to discuss the optimal way to measure each feature.
The
team must balance inspection cost (driven by speed) and test method validation
requirements (GR&R) to take advantage of DFM. This starts by determining
the best way to fixture the part, and then moves through the Excel file:
critical features first, then major, minor and finally negligible. Critical
features will need to pass gauge studies and therefore require metrology
capable of passing those studies, while negligible features do not need this
level of scrutiny.
Manufacturing review
Manufacturing
review follows metrology planning. This review examines each feature from the
metrology Excel grid – from critical to negligible – to determine the level of
manufacturing risk.
If any
concerns are identified during this review, they should be communicated to the
design engineer. Once the engineer has re-designed those areas of concern there
is a final manufacturing review to confirm the risk profile.
Post-processing review
The last step for the technical team is reviewing any
post-processing procedures and their impact on DFM. It is imperative for the design engineer to be acquainted
with the design rules for each of the post-processes.
There are a variety of procedures to be considered, both
large and small. Color
anodizing is one example. One color is less expensive than two because of the
manual labor required to mask two colors. Two colors can also be more expensive
because of the narrow processing range to get those colors. These details can
have a big impact on cost and time to create a final product, which influence
DFM.
If you work with a manufacturing partner, it’s important to
understand how their methods influence the manufacturing process and align with
a DFM approach. By taking a systems perspective, design engineers can better meet design intent while
minimizing cost and ensuring an on-time project launch.
Contact Lowell at (763) 425-3355 or requestinfo@lowellinc.com to learn more
about our DFM capabilities to improve time to market.
No comments:
Post a Comment