1. P08428: Design for Manufacture Introduction
Christine Lagree
Industrial Engineer
Product Design and Development, 4th Ed.
Karl T. Ulrich and Steven D. Eppinger
3/13/2008

2. Overview of the DFM Process
Estimate the manufacturing costs.
Reduce the costs of components.
Reduce the costs of assembly.
Reduce the costs of supporting production.
Consider the impact of DFM decisions on other factors.
3/13/2008

3. 1) Estimate the manufacturing costs.
Component costs
Standard (purchased from suppliers)
Custom (designed in house, raw materials, processing, tooling)
Assembly costs
Labor
Equipment and tooling
Overhead costs
Support costs (material handling, QA, purchasing, shipping, receiving, facilities, equipment maintenance)
Indirect allocations (cannot be linked to one product but necessary to stay in business, not relevant to DFM)
3/13/2008

4. 1) Estimate the manufacturing costs.
Fixed costs
Incurred at a predetermined amount, regardless of how many units are manufactured (machines, tools, may change over time)
Variable costs
Incurred in direct proportion to the number of units produced (raw materials)
3/13/2008

5. 2) Reduce the costs of components.
Redesign components to eliminate processing steps
Economies of scale
Fixed costs are divided among more parts
Variable costs are lowered, justification to buy larger and more efficient equipment
Standardize components and processes
3/13/2008

6. 3) Reduce the costs of assembly.
DFA index =
(theoretical min # of parts) x (3 seconds)
Estimated total assembly time
3 seconds reflects the theoretical minimum time required to handle and insert a part that is perfectly suited for assembly (quick as placing ball in circular hole)
Maximize ease of assembly
Part is inserted from top of assembly
Part is self aligning
Part does not need to be oriented
Part requires only one hand for assembly
Part requires no tools
Part is assembled in a single, linear motion
Part is secured immediately upon insertion
Consider customer assembly
3/13/2008

7. 4) Reduce the costs of supporting production.
Inventory management
# production workers
Supervision
Engineering support
Quality assurance
Minimize systemic complexity
# of new parts, new vendors, custom parts, new major tools, new production processes
Error proofing
Exaggerate differences
Eliminate subtle differences
Color code (not to add time to production)
3/13/2008

8. 5) Consider the impact of DFM decisions on other factors.
Development time
Annual cost savings vs. delay time
Development cost
Product quality
Ex: reduce size (amount of mat’l), reduce product strength
External factors
Component reuse
Lifecycle costs (toxic materials, service costs, warranty costs)
3/13/2008