Six Sigma Keys to Lean Maintenance Reliability

I have written various articles on FISHing (Field Implemented Stress Hardening) and for Six Sigma DFR engineers, articles on “FISH DMAIC” (First Integration of Stress Hardening). My website also addresses this powerful methodology for maximizing equipment reliabilty. But, continued questions in my seminars and from my website (at: www.amemco.net), have encouraged me to start this blog on lean maintenance reliability and FISHing so that others my find a ready source for these commonly asked questions and answers.

Questions such as what is FISH DMAIC or FISHing and how does it fit into the Six Sigma tool set for quickly and effectively maximizing equipment uptime, reliability, availability and this profits. Why is FISHing needed when we already have FTA, FMEA, HALT/HAST, Reliability Growth tracking, etc.? Does FISHing replace or augment these powerful methodologies? No.

However, FISH DMAIC fills a critical gap in the DFR Reliability Engineering Methodology and FISHing provides possibly the only opportunity to increase reliability on IB (install base) equipment now deployed by the thousands into the market place. I acknowledge to opportunity of going back on the IB and conducting FMEA and/or PofF to press for re-design, but this rarely happens. Even when they are being utilized, FISHing will greatly reduce the need for such redesign.

Why? Because FISHing is the exact 180 degree complement, counter-part complement to HALT. Highly Accelerated Life Testing presses or percipitates, by increased stressing during the design phase, weak components or “weak links” in the desing so that they can be corrected before building 2,000 or 100,000 units for market distribution. HALT is probably the most productive thing that can be done in the design phase to increase reliability when done properly (well discuss this further on). But, HALT allows for finding the weak points and correcting with a more rubust design. The opposite of that, and equally productive in increasing reliabilty, is FISH. By Stress Hardening the component, sub-system, or system, we find MTBF stretching way out, by orders of magnitude because the “normal stresses” can no longer get to the system to do their havac.

Therefore, once a system or piece of equipment is put into production and thousands are out in the field, FISHing is a most effective way to identify the actual “real world” environment and the root cause stresses effecting shorter than expected MTBF and ways (usually simple and easy to install ways) can be identified to protect the unit or system from those root cause stresses. Thus to the new “protected environment” the design acts as “more robust” overall and greatly improved MTBF is observed. For example, why would electronic devices ever fail or malfunction if not stresses by over current, heat, vibration, dirt build-up, oxidation, corrosion, power surges or lightning storm transients. FISHing as an evaluation in the field, sees these stresses for what they actually are, in the field, and provides effective ways to eliminate or protect any given system from those stresses. Thus, maximized uptime, reliability, life, availability and productivity.

Enough for now. I’ve got to go to bed. Leave your comments or questions and I’ll try to answer.