PDF documents comprise the majority of service and parts information, yet it is difficult for IT systems to extract data from a PDF file. This limitation negatively impacts parts and maintenance operations for all industries; this post addresses the impact on aviation, but in future posts we’ll look at other industries beyond aviation.

The Role of Task Cards

Task cards (or “job cards”) are documents containing detailed instructions that guide aviation technicians as they perform maintenance on airframes, engines and components. Task cards are critical to ensuring fast, accurate maintenance and regulatory compliance. Task cards may be physical (paper) or virtual (electronic) documents, depending on the business process of the airline or third-party maintenance shop (MRO). Each task card contains the information (parts, procedures, tools, skills, etc.) necessary to work on a specific piece of equipment (by tail-number/serial-number) and must be signed-off when the job is complete.

PDF Maintenance Documents

The parts and procedures defined on task cards are based on OEM maintenance manuals but also include airline best practices, in the form of customer originated changes (COCs) or customer supplements. The ATA (Air Transport Association) recommends that these OEM maintenance manuals use SGML or XML as the data format; however about seventy percent of the manuals currently in use are PDF. (Component maintenance manuals, which make up a high percentage of the serviceable items on an aircraft, are provided almost entirely in PDF format.) This is a problem for maintenance organizations because SGML and XML are highly-structured formats that simplify data extraction; however, the lack of structure in PDF makes it difficult to convert the text into task cards.

Another issue is that OEMs update aircraft, engine and component manuals on a regular basis (typically quarterly), and often specify different parts and procedures for individual aircraft tail-numbers (or equipment serial-numbers). To ensure accuracy, each new OEM revision must be compared to previous maintenance manuals and combined with the relevant COCs and supplements before being converted into updated task cards. With so much PDF data being modified so frequently, airlines and MROs have difficulty synchronizing technical content for maintenance planning and execution.

PDF Limitations

Aviation maintenance manuals and parts catalogs are broken down into tasks/subtasks and assemblies/parts, which are readily understood by engineers and technicians. Regardless of the data format used for this information (SGML, XML, PDF, etc.), end-users will see little difference. It is when a software system (ERP, EAM, MRO, etc.) tries to utilize this data that the limitations of PDF become clear.

Maintenance manuals that use SGML or XML employ special identifiers that call out tasks, subtasks, parts and other relevant information. These data elements (TASK, SUBTASK, PNR, etc.) allow text within SGML/XML files to be recognized and utilized by other business and IT systems. PDF, on the other hand, is a linear stream of text without any content identifiers or embedded data elements (only formatting rules and a few metadata fields). As a result, for an IT system to extract data from a PDF file it must first search the document and the results must be interpreted to identify the proper information. This is a slow, error-prone process that eliminates the benefits of automation. To effectively use PDF, maintenance organizations are forced to cut-and-paste the necessary data from PDF into whatever planning and inventory systems they are using. To make PDF useful for maintenance automation, the SGML/XML data elements that are missing from PDF must be “inserted” in a way that allows it to act more like the other, richer data formats. Only then can the maintenance organization realize the potential of fully integrated IT systems.

Overcoming PDF Limitations

Enigma has the ability to overcome the limitations of PDF documents, processing them in a way that enables this relatively flat file format to act almost like SGML and XML data. Enigma’s tools enrich PDF files, allowing them to be leveraged by maintenance planning and execution processes, like automatic generation of task cards. With PDF data comprising well over half of the airframe, engine and component documentation, airlines and MROs are finding Enigma’s PDF tools to be critically important to improving maintenance productivity, accuracy and compliance.

To learn more about how Enigma enhances PDF, download our fact sheet, "Putting PDF to Work – Making PDF Data Interactive."