3. Discussion and conclusions
Airlines often believe that their industry’s uniqueness
comes from a combination of four market characteristics:
global need for parts, demand unpredictability,
traceabilityof parts for safety reasons, and high cost of
not having a part (AOG). There is some evidence that
MRP offers the scope for accuratelycontrol ling
inventoryfor reducing stock for schedule airline
maintenance. However, presently, few companies use
the MRP system, but from the survey it is seen that of
the 152 companies who still use the ROP system, about
half are dissatisfied and considering implementing the
MRP system.
There appears a need to classifyproblem s that arise
from MRP use into those associated with management
and those arising from technical sources. Of the reasons
management cites for MRP system failure most could be
resolved with comprehensive MRP education and
training prior to and during implementation. The
technical sources of difficultyof implementing MRP
cited ranged from unpredictable consumption of parts,
through unscheduled parts requirements (on-condition
maintenance), to difficultyforeca sting with unpredictable
parts. There are ways around some of these—e.g.,
Ghobbar and Friend (2003) discuss the forecasting of
intermittent demand in relation to these primary
maintenance processes.
In conclusion, the MRP surveyde termined that
planning horizon length varied among companies
depending on the type of work at hand, in accordance
with their planning forecast. We intend to look at the
effect of this factor on the MRP lot-size in conjunction