DESIGN FOR MANUFACTURING AND ASSEMBLY Abid Sandila

AGENDA: Design for Manufacturing Design for Manufacturing & Assembly (DFMA) DFMA Steps DFMA key objectives & examples

DFMA Quality Cost Time to Market Function

Design for manufacturability (also sometimes known as design for manufacturing or DFM) is the general engineering art of designing products in such a way that they are easy to manufacture at the lowest possible cost. DFM describes the process of designing or engineering a product in order to facilitate the manufacturing process in order to reduce its manufacturing costs. DFM activity is related to optimization and adaptation of product design in order to reduce cost, time, and resources during manufacturing. DFM will allow potential problems to be fixed in the design phase which is the least expensive place to address them. Other factors may affect the manufacturability such as the type of raw material, the form of the raw material, dimensional tolerances, and secondary processing such as finishing. Depending on various types of manufacturing processes there are set guidelines for DFM practices. These DFM guidelines help to precisely define various tolerances, rules and common manufacturing checks related to DFM. While DFM is applicable to the design process, a similar concept called DFSS (Design for Six Sigma) is also practiced in many organizations.

Can you find number of letter F’s in this sentence? “Finished files are the result of years of scientific study combined with the experience of years.”

Can you find number of letter F’s in this sentence? “Finished files are the result of years of scientific study combined with the experience of years.”

Introduction to Design for (Cost Effective) Assembly and Manufacturing The words “Cost Effective” have been highlighted in red and put in parentheses. This is there to emphasize that we only do this activity to make the overall “cost” of the assembly and part manufacturing lower. This includes costs associated with difficult assembly (thus taking more time/labor), quality defect costs (due to omitted, wrong or assembled wrong errors, etc.) and other costs associated with poor designs. The order of “Assembly” and “Manufacturing” was switched from the traditional order (the one that the standard “DFMA” acronym came from) in order to highlight that we actually want to do DFA first and then do DFM.

Question: What do we do first… Question: What do we do first…..Design for Manufacturing or Design for Assembly? Answer: We do DFA first, then DFM. That way you’re not wasting your time optimizing the manufacturing processes on component parts that you might end up eliminating from the assembly.

About 75%-80% of quality issue during mass production are due to design Design for Manufacturing Aims to: Reduce material, overhead and labor cost Shorten the product development cycle Focus on standards to reduce cost

DFMA Steps: Analysis Redesign Conclusion Conceptualization Affordable/attractive, serve the purpose its designed/used for Analysis Redesign Conclusion

DFMA Steps: Analysis Redesign Conclusion Conceptualization Components, Processes, Combined Components, Main Assembly and or subassembly -Is the component moving? -Is the component required to be removed for maintenance? -Can it be made from different material? Redesign Conclusion

DFMA Steps: Analysis Redesign Conclusion Conceptualization From these questions, suspect components and processes should be identified and redesigned. Conclusion

DFMA Steps: Analysis Redesign Conclusion Conceptualization Reports, Participants, evaluations, tests, etc. https://www.youtube.com/watch?v=C31RPvtFw6k

Key Principles in the DFMA Process: 1. Minimize part count 2. Standardize parts and materials complexity 3. Create modular assemblies 4. Design for efficient joining 5. Minimize re-orientation of parts during assembly and/or machining 6. Simplify and reduce the number of manufacturing operations 7. Specify ‘acceptable’ surface finishes for functionality

Key Principles in the DFM Process: 1. Minimize part count ‘..If more than 1/3 of the components in a product are fasteners, the assembly logic should be questioned.’ 24 Parts 8 different parts multiple mfg. & assembly processes necessary 2 Parts 2 Manufacturing processes one assembly step

2. Standardize parts and materials complexity

3. Create modular assemblies

3. Create modular assemblies (contd.) (standardization of sub-systems….) All components can be removed as single pieces, which assists with servicing and troubleshooting. Can make the modules themselves expensive (and certainly more expensive than the one component that actually broke) but this is the trend in industry. Makes for faster repairs, less trouble-shooting time and quicker service events in general.

4. Design for efficient joining

5. Minimize re-orientation of parts during assembly and/or machining

6. Simplify and reduce the number of manufacturing operations Lean Manufacturing Henry Ford was one of the first people to develop the ideas behind Lean Manufacturing. He used the idea of "continuous flow" on the assembly line for his Model T automobile, where he kept production standards extremely tight, so each stage of the process fitted together with each other stage, perfectly. This resulted in little waste. Pessimist: Half Empty Optimist: Half Full Lean Thinker: Can I reduce the glass half the size?

Toyota Production System (TPS), which uses Just In Time (JIT) JIT usually identifies seven prominent types of waste to be eliminated: Waste from Overproduction ∙ Waste of waiting/idle time Transportation Waste ∙ Inventory Waste Processing Waste ∙ Waste of Motion

7. Specify ‘acceptable’ surface finishes for functionality

abid.sandila@dicefoundation.org