1. Design for Manufacture and Assembly (DFMA) BDD 4013
Bachik bin Abu Bakar

2. Introduction Is a combination between DFM & DFA Design for Manufacture
Manufacturing of individual component parts of a product or assembly
Design for Assembly
DFA
Addition or joining of parts to form a complete product

3. DFM?
The design for ease of manufacture of the collection of parts that will form the product after assembly.

4. DFA?
The design of the product for ease of assembly.

5. Where to apply?
To the design team in simplifying the product structure, to reduce manufacturing and assembly costs, and to quantify the improvements by using concurrent engineering approaches.
As a tool for benchmarking to study competitor’s products.
As a should-cost tool to help negotiate suppliers contracts.

6. DFMA
If the cost of making a change to a product during its conceptual design phase is RM1K,
Then the cost of making the same change after the drawings are released and the initial prototype are fabricated is approximately RM10K,
If this same change is not applied until the production run has started, the cost impact will be approximately RM100K,
If the need for the design change is not recognized after the product has been purchased, the total cost will be approx times more than during conceptual design review.
Intended to increase the awareness of engineering design team to the need for concurrent product and process development.
Design process is where about 80% of product’s total costs are determined.
The cost of making changes to a product as it progresses through the product development process increases by orders of magnitude at various stages.

7. The Six Basic Considerations
SIMPLICITY
STANDARD MATERIALS AND COMPONENTS
STANDARDIZED DESIGN OF THE PRODUCT ITSELF
SPECIFY TOLERENCES BASED ON PROCESS CAPABILITY
USE OF THE MATERIALS MOST PROCESED
COLLABORATION WITH MANUFACTURING PERSONNEL

8. The Ten Commandments Minimize the number of parts1
Minimize the number of parts 2
Minimize the number of fasteners 3
Minimize reorientations 4
Use multifunctional parts 5
Use modular subassemblies

9. The Ten Commandments Standardize Avoid difficult components6
Standardize 7
Avoid difficult components 8
Use self-locating features 9
Avoid special tooling 10
Provide accessibility

10. Simplicity Minimize the number of parts Minimize the use of fasteners
Minimize reorientations
Use multifunctional parts
Use modular subassemblies

11. How to keep part count minimum?
Key principles revolve around THREE questions: 1
Does the part move? 2
Does the part have to be made from a different material than the other parts? 3
Is the part required for assembly or disassembly?

12. The part’s function can be combined with another existing part
If all answers is NO
The part’s function can be combined with another existing part

13. The effects of reduced part counts?
Higher reliability.
Lower configuration management, manufacturing, assembly, inventory costs.
Fewer opportunity for defect.
Reduced cycle time.

14. Why do we need fastener? Offers flexibility Ease for adjustment
Quick component replacement or modularity

15. Why fasteners should be minimized?
Increase the cost of assembly
Increase inventory costs
Reduce opportunity for automation
Reduce product reliability
Expose to employee health risks
PROTOTYPE DESIGNS MAY REQUIRE ADDITTIONAL FASTENERS AND INTERFACES TO TEST VARIOUS DESIGN OR COMPONENT OPTIONS
PRODUCTION DESIGN SHOULD BE STRIPPED OF ANY EXCESSIVE FASTENERS

16. Minimum Orientations Guiding principle are:
To create a design that can be easily assembled with minimum use of special tooling.
To always use gravity to aid you in assembly.
Minimizing number of fasteners will obviously headed for minimizing number of orientations needed.

17. Multifunctional Parts
Is a primary method of reducing the total parts count.
Thus, enhancing design simplicity.

18. Modular Subassemblies
Good design method to predesigned for continuous product improvement through block upgrades.
Promote similar product line enhancements over time.
As new technology moves into practice and becomes cost effective, modular subassemblies can be easily replaced to provide expanded capabilities, higher processing speeds, market competitiveness or more economical substitutions.

19. However,
It may increase the total part count of the original product.
Positive trade-off could yet be achieved by the added ease and speed of implementing improvements for many products or product families.

20. Use Standard Materials Components and Designs
Its describe the sixth commandment – STANDARDIZE
Design reuse – Most cost-effective method
By defining company-or product family-related standard materials, standard parts, specific design process standards. – Reduce cost and TTM, while reliability will be maximized.

21. The key element of standardization;
Establish the discipline within the organization to keep the standards current and readily available to the PD team.
Enforcing their effective and consistent use.

22. Specify Tolerances
Embodied in seventh commandment – Avoid Difficult component.
It is based on process capability not from design engineer’s affinity.
CE approaches in PD team is the most effective way to achieve. – Design Engr.

23. Use of Common Materials
The fifth design consideration – use of the materials most processed.
Materials that are commonly machined or processed should be the first choice for various components.
Exotic or state-of-the-art processes or materials should be avoided.
To preclude extended process activities – C↑,TTM↑, Quality↓, & Reliability↓

24. CE Collaboration The sixth design consideration.
Its essential for the design team to include cross-functional personnel such as;
Manufacturing engineers
Quality engineers
Procurement specialists
To ensure all the appropriate design trade-offs are properly analyzed and selected.

25. Cont…
The traditional ‘Over-the-wall’ approach is guaranteed to produce product attributes that contribute to Higher production cost & Longer TTM.

26. The Final Three Design Commandment
[8] To use self-locating features
An assembly aid to reduce assembly cost & time.
Reduce the handling, alignment, reorientation, and inspection cost of assembly.
Automated assembly processes are tremendously benefited.

27. [9] To avoid special tooling
Harbors an extensive array of hidden costs.
Cost of designing, fabricating, checkout, inventory, maintenance, spares, and planned for replacement.
Added cycle time to assembly process through - Issuing it from stores, moving it, installing it, and then verifying its proper placement, alignment, attachment, and operation over its intended design life.

28. [10] To provide accessibility
Implies the need for maintenance, inspection, part adjustment, part replacement, or other product access requirements over its design life.
The key is to define the requirement for accessibility based on customer’s needs and for the product growth or evolution in future.
Requires balance between satisfying customer needs and anticipating the most likely future needs.