FOCUS: Drive Train Reliability – DFSS
The drive train subsystem for this large-scale business product has a design target of 5,000 hours. The initial subsystem design, completed by an external motor supplier, was failing well short of this target. Such failure could require eight or more repairs over the targeted life. This was unacceptable both from a customer and a business perspective.
To fix this problem, the team identified the significant factors required to improve drive life, implemented the materials and design improvements and applied accelerated life testing and reliability tools to measure and project improvements in drive train life performance. The result was a 13X reliability improvement. The team used the following IDOV work process:
– Identify: Conducted gear failure analysis and defined the problem.
– Design: Modeled the baseline drive train and determined the necessary material properties and geometry factors to sustain the operational stresses.
– Optimize: Sourced a new powder metal gear vendor capable of delivering high density, high quality powder metal gearing. Also started initial accelerated life testing and reliability studies.
– Validate: Continued drive testing to validate reliability life projections and updated the drawings to specify new critical parameters and specifications.
Typically, DFSS has provided at least a one sigma gain in quality at launch over previous designs. This is a major improvement over other methodologies. Additionally, DFSS conservatively decreases time to market by at least 25%. A more typically seen reduction in time to market is 25%-40%. Cost savings due to total resources utilized, which is highly correlated to time, is in the 20%-40% range.
The team’s results produced robust design changes that yielded a 13X improvement in reliability and a 10X cost reduction. Additionally, the team adopted the IDOV process as the standard for all future redesigns and new designs of this type.
* Due to nondisclosure agreements, the organization referenced in this example cannot be disclosed.