Identifying Costly Assets – Using Data Analytics to Reduce Maintenance Costs
The fleet under review has 99 catering trucks. The question was “How can the cost of maintenance of
this fleet be reduced?” Data was gathered from 18 months of service records on 450 catering trucks.
The benchmarked cost of maintenance, parts and labor, for each asset for each month was then
established. The cost includes all repairs: preventative maintenance, found or corrective maintenance,
operator error and all major repairs.
During the period September, 2014 through November, 2014 the actual spend for maintenance for the
fleet under review exceeded the benchmarked expectations by 26%.
The Analysis
We are looking for assets that have major repairs or frequently need service. The objective of the
analysis is to find the Big Spenders and Frequent Visitors. The second objective of the analysis it to
determine ways to reduce the number of major repairs and frequent visits ultimately reducing the
total cost of maintenance.
Big Spenders
Seventeen percent of the fleet exceeded $7500 in maintenance spend during the review period.
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4 trucks over $15k
5 trucks between $10K and $15K
8 trucks between $7500 and 10K
The Diesel Particulate Filter (DPF) is identified as a recurring contributor to problems in these trucks.
Two model years of one make of truck accounted for 50% of the major repairs for reviewed fleet.
Frequent Visitors
Twenty-one trucks had 20 or more unscheduled service calls during the period.
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The fleet required an average of 14.7 unscheduled service calls per day.
The average number of visits per truck was 13.5 for Sep-Nov.
Eighty-five percent of the frequent visits fell into two categories:
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“Jump Start”
o 40% appear to be hard start related issues
o 40% of jump starts appear to be driver error related, ie. Lights or key left on
o 10% may be attributable to battery or charging system issues
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DPF/Re-gen issues
o DPF regeneration cycles are being missed
o Operators continue to use vehicles that indicating DFP failure
Note regarding Diesel Particulate Filters: DPFs require re-generation on a specific interval. The
automated regeneration generally requires the vehicle to be operated at highway speed to create the
heat necessary to clean the DPF. Vehicles servicing the airport rarely achieve highway speed and
require a different plan for regeneration or the DPF becomes restricted. Operators will occasionally
push through the warnings and do extensive damage to the engine.
Global Aviation Services – www.globalaviationservices.com
Initial Recommendations:
1- Review the PM schedule for all trucks.
The data suggests that at least two makes of vehicle need to be seen more frequently than the
standard 400 hour cycle. Cycle should be modified to 250 or 275 hours and then monitored to
see if less significant engine damage occurs.
2- A strategy must be developed to mitigate high cost repairs resulting from DPF failures.
 Identify by asset, engine type and DPF re-gen trigger:
o Pressure Sensor
o Fuel Used
o Miles Traveled
o Hours Run
 Track triggers on each asset
3- The DPF regeneration process varies by make and model of asset. Depending on the fleet make
up, there could be six or more different methods for regenerating a filter. Notation regarding
the DPF regeneration should be incorporated into PM checklists.
4- Test switching from wet cell batteries to Absorbed Gas Mat (AGM) battery.
AGM batteries are manufactured with purer components that decrease resistance. In addition,
their internal construction increases conductivity. This combination produces significantly
higher cold start power and much faster recharge time. This typically reduces unscheduled
maintenance calls especially during winter operations. (Noteworthy but not as important in the
catering truck assessment, AGM batteries are much less susceptible to damage from vibration
due to poor/no suspension.)
5- Test all Glow Plugs and Glow Plug Circuits
The fuel in a diesel engines needs to rise to a temperature that will auto-ignite. In cold
weather, glow plugs, essentially small, inline heaters, heat the air-fuel mixture to assist in cold
starting.
The Goal
The goal should be to bring the costs in line with our benchmark. The average cost per asset per
month should move down 22%.
Global Aviation Services – www.globalaviationservices.com