THE TECHNICIAN'S MASTERPIECE

A fully assembled and repaired expensive complex machine is the technician's masterpiece.  Those not in the profession have likely not given this much thought. Those who are have.   It's the ultimate expression of the tech's pride, experience and competence.  Uneventful outcomes showcase the skills of the error resistant technician.  Bad results weed out the less talented ones.

Look no further than the machine.  Any technician's collection of works will tell his or her story.  The successful professional with a solid reputation leaves a trail of works that are mind boggling.  Countless tens of thousands of capscrews and components have been assembled error free over a period of decades, with the machines speaking for the skill of the technician who assembled them.

pieces
At center stage above is a Pratt & Whitney R1340-AN1, 600 hp takeoff rated. I installed it on the left wing of a Grumman Mallard amphibian scheduled passenger carrier in 1980, and 3 months later it ended up on the bottom of the ocean off Avalon, California because of a non fatal pilot error accident.  Above left is a Cummins ISX 530 that I repowered a Peterbilt 359 with in 2006, a truly great engine.  At right is a Bell Helicopter Textron 222B powered by problematic twin Textron Lycoming LTS101-750C3 gas turbine turboshaft engines rated at 743 shaft horsepower each in a 245 lb package.  The machine was fast with a 170 mph cruise speed.  During the teething period of the LTS101 engines in the 1980's, we averaged 140 hours between engine removals on this and other aircraft with the same power source. A never ending stream of corporate and engineering level mistakes plagued the engine throughout the eighties, leaving customers frustrated and disappointed.  The engine has since matured to reliability but a bad reputation is difficult to overcome.


Obviously, professional engine technicians make mistakes.  During a recent engine assembly, I counted about 10 "captured" mistakes in the first hour of one day (it was a Monday), ranging from looking for a tool that I should have had nearby to dropping a capscrew on the ground to losing focus because of a distraction.  These are all low level errors that we don't even think about.  When you pay attention to detail like this, it can be humbling.  Humans are constantly dealing with error corrections and error capturing.  "Error capturing" will be discussed later.


BOEING'S PROCESS FOR DEALING WITH MAINTENANCE "EVENTS"
Boeing Commercial Airplanes, a leading manufacturer of the world's finest airliners for the past 80 years, took a giant leap forward in the area of human behavior.  Mistakes made by technicians have been a costly fact of life over the decades.  The process is known as "MEDA", or Maintenance Error Decision Aid".  The next page explains it in more detail.  In a nutshell, the program outlines an investigation process of errors made by maintenance technicians, including the technician in the process instead of penalizing him in most cases.  The information gained is disseminated to help avoid the contributing causes in the future.  Pretty forward looking in my opinion.

Four MEDA related documents and 3 books will be referenced here and you can briefly check them out.  The books are not online and need to be accessed if you are curious about them.  The best of the three books is "Managing Maintenance Error" by James Reason and Alan Hobbs.  I would suggest skimming them if you want and going back to them later if you decide they interest you.  They've actually completely changed the way I work and think while on the job:

A.  The Boeing MEDA Guide (pdf)
B.  Boeing's AERO Magazine 2007 2nd Quarter, Article 3: The MEDA Investigation Process

The documents below are a little dated from the year 2000:
C.  Human Factors and Ergonomics Society / Institute of Education Sciences proceeding at the IES / HFES 2000 Congress
D.  International Journal of Industrial Ergonomics 26, 2000, pages 261 to 276; Development and evaluation of the Maintenance Error
Decision Aid (MEDA) process

Books:  The links go to Google Books from which some but not all content can be sampled:
1.  Managing Maintenance Error by James Reason and Alan Hobbs
2.  Human Error by James Reason
3.  Resilience Engineering by Erik Hollnagel, David D. Woods and Nancy Leveson


Boeing MEDA program started in 1995.  It has expanded in scope recently.  AERO Magazine is published quarterly by Boeing Commercial Airplanes.  The 2007 2nd quarter issue included article 3, titled "The MEDA Investigation Process".  The article is good reading.  The AERO link should be looked at and you can browse the entire archive of AERO articles.  They relate to safety and analogies can be drawn in our industry.

THE NEW EXPANDED SCOPE OF MEDA INTO OTHER COMPANY PROCESSES AND PROCEDURES
Boeing's AERO Magazine Q207 article 3 states that "Boeing has recently expanded the scope of this tool to include not only maintenance errors but also violations in company policies, processes, and procedures that lead to an unwanted outcome."

An unwanted outcome..  Where have I experienced that before?  Where and when have you?  Well folks, there is a sensible and systematic way to analyse and correct some of the more expensive "unwanted outcomes" that we are all a part of from time to time. 

The best thing to do is to browse over the MEDA documents referenced in this article, then read them.  They lay out the philosophy, history and implementation of a "maintenance event" investigation process.  Still interested?

PAGE THREE

BACK to TM page one