Design Phase Introduction
Key to a reliable product is the many design decisions, and for each decision, designers balance reliability with cost, time-to-market and performance objectives. Reliability Models and Predictions provide prioritization and feedback for each decision. Analysis of the system reliability or availability connections to key modules or components through Reliability Block Diagramming or Fault Tree Analysis help establish realistic sub-system goals and identify high risk areas in the design. Failure Modes and Effects Analysis provides a structured method to identify potential risks, their impact, and mitigation effectiveness.
Tools to Address Specific Design Challenges
A wide range of methods are available to the design engineer to make decisions. Heat is a common accelerant of failure mechanisms; therefore, Thermal Analysis techniques provide feedback to mitigate this problem. Proper Derating Analysis minimizes a wider range of stresses for electronic components. For mechanical components Tolerance or Worst Case Analysis performs a similar function and can help with Material Selection. For complex design issues, statistical methods including Design of Experiments can quickly optimize reliable solutions. Finite Element Analysis (FEA) is a general tool to develop better designs more quickly and with few physical prototypes. FEA can be combined with Design for Six Sigma techniques and Dynamic Analysis to better understand the effects of key parameters on the overall design. On early designs a Sneak Circuit Analysis provides a check for unintended product behavior (hardware/software design defects). Software also has reliability concerns; therefore, Software Reliability techniques can establish well documented methods to produce nearly bug free code.
Design Wrap Up
As the design evolves, key elements of information provide other parts of the organization critical information. Warranty Prediction assists in key business decisions. The expected product failure rate over time feeds into Maintainability/Preventive Maintenance considerations in the design. Plus, effective Design Reviews and Retrospective Events help the organization identify, remove, and avoid reliability issues.