Case Study: Application of Algorithm DFMEAs

Failure Mode and Effects Analysis (FMEA) is a tool to analyze potential risk in product designs, manufacturing processes, and custom built machinery.

PlanTech developed a methodology to use the FMEA tool to analyze software / algorithms by comparing outputs of an algorithm against the inputs.

An algorithm is a logical entity designed to perform a specific function or set of functions. It may consist of one or more subroutines. It receives logical inputs, which it uses to calculate the desired output(s).

Inputs can be via sensors or multiple other algorithms commonly called rings.

Types of Algorithms:

Control algorithm

An algorithm the primary purpose of which is to report data from one or more sensors, or to control some electromechanical function of the vehicle.

Diagnostic algorithm:

An algorithm the primary purpose of which is to detect and report an error in another data item and / or the sensors which determine the data item. For example, in automotive diagnostic algorithms, before the catalyst monitoring diagnostic can return reliable results, the engine must be warmed up, so coolant temperature is checked. The inputs used for these checks are termed enable criteria. This distinction is especially useful in dealing with algorithms that have a lot of enable criteria and more than one output

PlanTech worked with the Powertrain division of an OEM facilitating Algorithm Failure Modes and Effects Analysis (AFMEA) on a software ring pertaining to Performance Launch Control (PLC).

The subject matter experts who attended were a Global Technical Specialist, two Algorithm Engineers, a Service Engineer, and a Software Calibrator. The AFMEA was initiated well in advance of the design release date. During the subsequent meetings the potential failure modes discovered and mitigated with action items would have resulted in large warranty costs if not caught ahead of time within the AFMEA. In addition, the AFMEA meeting was the only time this array of engineers was assembled for discussion regarding the design of the PLC ring. Normally they work individually with minimal interaction. This communication enabled the critical discussion to occur that streamlined the design and headed off downstream warranty costs. The entire group commented at least once per meeting how valuable the AFMEA exercise was as a part of their design development process.

The results:

PlanTech is a division of Omnex Inc.

Omnex is an international consulting, training and software development organization specializing in management system solutions in Quality, Environmental, and Health and Safety standards-based management systems. Omnex also leads the way with Lean, Six Sigma and other breakthrough systems and methods of performance enhancement, supported by Omnex Systems, LLC, software solutions for Enterprise Wide Quality Management Systems®.