Improved Maintenance Process

 

The U.S. Navy’s premier tactical aircraft is the F/A-18 Hornet. It is the workhorse of the Naval Aviation enterprise which also includes aviation units of the U.S. Marine Corps. The F/A-18 is a supersonic, twin engine, all-weather-capable fighter and attack aircraft that is made in both single-seat and dual-seat variants. It can operate from either aircraft carriers or land bases. The famous Navy flight demonstration team, the Blue Angels, has been flying the F/A-18 for many years. In all, some 1,200 F/A-18 aircraft are deployed with both U.S. Navy and Marine Corps forces. (See Figure 6.)

 

The F-404 engine is the critical component that keeps the F/A-18 fleet in the air.  Leading up to June 2000, the F/A-18 community at Naval Air Station (NAS) Lemoore in California faced a shortage of F-404 engines that had severe detrimental effects on readiness (the ability to have aircraft ready to fly at any given time). This shortage caused aircraft to be grounded, waiting for engines to get fixed. At NAS Lemoore, alone, 30 aircraft sat with no engines despite the fact there was   a backlog of 35 engines being repaired.   The engine shops responsible for fixing these engines not only faced an ever-increasing high backlog but they also faced production inefficiencies and low morale.   As the problems grew, the engine mechanics were working 12-14 hour shifts, but were not able to solve the problem doing business as usual.

 

 

Navy leadership began removing barriers that were stalling the engine repair process. For example, in the consumable parts storeroom, personnel were working two 8-hour shifts even as the engine shops were working around the clock. This created situations where engine repairs were delayed waiting for the storeroom to open. This situation was corrected. However, by far the biggest decision made was to bring in Lean Six Sigma experts from private industry to identify and remove wasted activities and efforts from the F404 engine repair process.   These experts used Lean and Six Sigma tools such as value stream and variation analysis to quickly identify this waste and remove it.

 

 

As with the MRAP case described previously, the results were profound. The elimination of waste in the process increased the productivity of repair crews five-fold from eight repaired engines per month to 40.   Further, the number of maintenance days (or the cycle time to repair an engine) was reduced from 83 days in 2001 to 14 days in 2002—a huge reduction of 83%.   This dramatic improvement was then exported to the nine other engine repair facilities within the Naval Aviation enterprise with the same results. The combined effect of these improvements was that the Navy was able in 2004 to begin consolidation of repair facilities from nine to two, was able to retire excess inventory of 40 engines and was able to identify 48% excess manpower reducing engine repair workers from 350+ to 167.

 

Figure 7 shows a comparison of one of the engine repair shop floors at NAS Lemoore prior to introduction of LSS techniques and after. As can be seen, the “before” photo shows the floor crowded with many engines in various states of repair. The “after” photo shows an uncrowded floor with a much more manageable (smaller) number of engines in work.

 

This case is further evidence of the dual benefits that result from applying LSS to Government operations. The Navy and Marine Corps were provided with more aircraft in service at any given time which increased readiness. The taxpayer was provided with increased productivity of Government workers, elimination of the cost of operating unneeded facilities and reassignment of workers to other areas of operation.