DECISION MAKING IN AIRCRAFT MAINTENANCE PRODUCTIVITY

As a result of Global economical crisis, MRO centers are persuaded to be more productive in their processes. Productivity has a direct relation with affective use of resources such as human beings and material. The goal is to gain more profit by using less resources in aircraft maintenance while maintaining the appropriate level of safety. If productivity is high it does not mean that there is adequate level of safety in a MRO.  

 Safety is the danger, risk, injury, or loss to personnel and/or property, whether caused intentionally or by accident. All of the aviation rules concentrate the potential implications of human error and human factors failings upon aviation safety and not on how human factors affects the individual’s efficiency. However, if good human factors principles are applied within maintenance in order to improve safety, there should also be associated benefits that can be realized for the aviation personnel. 

 Productivity is; the amount of output per unit of input (labor, equipment, and capital). There are many different ways of measuring productivity. For example, in a factory, productivity might be measured based on the number of hours it takes to produce a good. In the service sector productivity might be measured based on the revenue generated by an employee divided by his/her salary. In a MRO, it might be measured based on the total manxhours, materials or time spend divided by number of letter checks.  

 Efficiency is the evaluation of performance of a unit. The evaluation can be accomplished by calculating level of production in comparison with resources and cost. A level of performance that describes a process which uses the lowest amount of inputs to create the highest amount of outputs. Efficiency relates to the use of all inputs in producing any given output, including personal time and energy. Inputs such as; time, money and raw materials are limited, while maintaining an acceptable level of output or a general production level, they should be conserved. Being efficient means reducing the amount of waste in the inputs. A commonly used measure of efficiency is the ratio; output variables divided by input variables.  

 Safety related productivity is the total productivity calculated by taking into account of human factor affect.  

 High productivity is important for competitive MRO’s. If MRO’s can not catch human related errors which affect safety and they can not stop them happening again, these human errors affect productivity too. Some human errors can cause big events such as, in flight turn backs, in flight shut downs, delays that cause big amount of cost to operators. Human errors start to show its affects in operation sometime after a year that the error happened. It is important to find mistake proof solutions for the human errors not to lost customers or money for a MRO. 

 Safety level is defined by using ICAO risk assessment in civil aviation. Although there is a relation between productivity and safety in reality, it is hard to find a reference in the litterature to show the relation. In this thesis, the relation between safety and productivity is given.  

 This thesis concerns with a productive MRO. It has increasing effectivity and efficiency by increasing number of maintained aircrafts. But also, it has potential safety problems which can affect its competency in the market. In this thesis, it is also shown that how human errors as part of safety, affect a MRO total productivity and MRO maintenance C-checks and how managers prioritize improvement activities to increase level of relative efficiency by using DEA. X-MRO is choosen for case study. Because data is provided by X-MRO.  

 Human errors are analysed for X-MRO between years 2006 and 2011. These errors compared with the other two MRO’s to calculate and compare their safety index.  

 In order to reduce the affect of human errors and to increase the productivity,  improvement events which were accomplished in X-MRO beetween 2006 and 2011 are shared. X-MRO total factor productivity, efficiency, effectivity are calculated between years 2007 and 2009 to see the relation between safety and productivity. 

 A MECI is defined to show the affect of safety on relative efficiency for the letter checks .  

 DEA is a technique that is used for measurement relative efficiency of similar units in an organization. If there are more than one input and one output it is difficult to calculate performance measurements of units. DEA method was used to compare relative efficiency of twelve A320 aircraft maintenance C-checks which were accomplished in X-MRO by including safety as output. It is used to compare relative efficiencies of C-checks. 

References

Bozkurt, Y., "Safety Related Productivity in Aircraft Maintenance", Ph.D. Thesis, ITU Institute of Physical Sciences, Department of Aeronautical and Astronautical Engineering, (2013).