In order to get a better understanding of wire degradation, this is a good view of task analysis for EWIS. This article discusses the second task “Data Analysis” in the series on EWIS Service Life Extension Program (SLEP). This is based on the new guidance developed by the USAF for the sustainment of aging aircraft EWIS and has been integrated with MIL-HDBK-525. The previous articles can be found here:
The second task in MIL-HDBK-525 describes the data analysis processes that can be used to determine hot spots, scale of EWIS repairs, areas for focus during inspection (task #3 – covered in the next article), and the overall risk assessment process to support EWIS SLEPs.
The following analytical methods can be used to identify conditions and/or performance gaps: visual observation, comparative analysis, statistical analysis, and analysis process. Each method can provide beneficial information, but only when used for a valid situation or environment with each described in more detail in the handbook.
The first step in the data analysis process is data mining. The data mining implemented will vary according to a specific project. However there are “best practices” that should always be implemented; these are included in the handbook. Field, depot, and engineering surveys are among the data mining techniques that address issues concerning EWIS components, subsystems, and management. The handbook provides suggestions as to the areas that should be covered in the directed questionnaires.
Maintenance databases also provide useful engineering data, although it can be a tedious task. The effort makes it a necessity to have subject matter experts clean the data and allocate the maintenance action reports into the correct groups. The handbook provides guidance on how this process can be streamlined to methodically review the information.
When reviewing the maintenance databases for information, the first objective is to select the necessary data; this may include such fields as work unit code, problem description, and corrective actions. Once the data is selected, a manual data review is performed and the data is categorized. After the data is reviewed, analysis techniques are used to provide additional information on EWIS related maintenance actions.
Scatter diagrams, a data analysis technique that illustrates a positive or negative relationship between two variables, may be used in the maintenance data analysis. Other analysis techniques include Pareto analysis, Cause and Effect diagrams, and trend analysis (an example of the Pareto analysis in shown in the figure above). In addition to data analysis, partitioning data techniques can be used to provide further insight.
The objective for Task 2 is data selection, review, and analysis. Task 3 (covered in the next article) will utilize the data analysis from Task 2 to perform a physical aircraft inspection.