Content Integration in the Aviation Industry Using CMIS

The recently approved Content Management Interoperability Services (CMIS) specification could play a very important role in ensuring that aircraft operators receive up-to-date maintenance and operation documentation from aviation manufacturers.

The safe and efficient maintenance and operation of air vehicles require clear, technically accurate, and up-to-date technical documentation. The technical documentation is supplied by original equipment manufacturers (OEMs), regulatory agencies, and the aircraft operator's own engineering staff. OEMs (e.g. airframe, engine, and component manufacturers) provide regular publications such as Aircraft Maintenance Manuals (AMM) and Flight Crew Operating Manuals (FCOM) as well as time-sensitive supplements such as Service Bulletins (SBs) and Temporary Revisions (TRs). Regulatory agencies like Transport Canada and the US Federal Aviation Administration (FAA) also publish technical information that affects the maintenance and operation of air vehicles and equipments. Examples are Advisory Circulars (ACs), Airworthiness Directives (ADs), and various forms and regulations.

A typical airline faces the following challenges:

• The elimination of the high costs associated with the shipping, storage, and distribution of physical products (paper, CDs, and DVDs) containing the technical documentation.
  
  
• The safety and regulatory compliance concerns related to the use of out-of-date technical information (currently, some airlines receive revisions to technical manuals only four times a year).
  

The aerospace industry is in the process of adopting the new S1000D technical publications standard. S1000D is based on the concepts of modularity, reuse, and metadata (see my post on S1000D Content Reuse). The Flight Operation Interests Group (FOIG) of the Air Transport Association (ATA) is developing a data model and XML Schema for flight deck procedures and checklists also based on the S1000D data model. While S1000D is the right payload format, the exchange between content management and publishing systems within the industry must be orchestrated in an efficient manner.

Airlines, repair stations, regulatory agencies, and original equipment manufacturers (OEMs) manage and publish technical content using proprietary content management systems (CMS) each with its own proprietary API. Some companies now provide online portals where customers can login to get the latest documentation. However, pilots and technicians don't really want to login into the support sites of all those content providers to find out what is new and updated. To minimize aircraft downtime, aircraft mechanics want to connect to the aircraft's health and usage monitoring system (HUMS), determine what problem needs to be fixed, and have the appropriate content aggregated (work package) and presented to them.

With CMIS, an airline or aircraft operator can create a portal to aggregate content from the repositories of its OEM suppliers using a single standardized web services interface based on either SOAP or AtomPub (the RESTful alternative). This allows the aircraft operator to keep their maintenance and operation documentation updated at all time without having to wait for a CD or paper manual to be shipped by the OEM.

The second scenario is distributed authoring driven by the shift to distributed aircraft manufacturing. For example, the content of the Aircraft Maintenance Manual (AMM) can be provided by different aviation manufacturers participating in a consortium to design, manufacture, and support a new aircraft. In such as a scenario, a centralized CMIS-compliant content repository (hosted by the airframe manufacturer acting as the content integrator) can provide the following CMIS services to other members of the consortium:

• Policy and ACL Services to obtain the policies (such as retention) and Access Control List (ACL) currently applied to a document
  
  
• Navigation Services to programmatically navigate the content repository
  
  
• Discovery services to query content. CMIS supports SQL-92 with some extensions and full-text search and can handle federated search across multiple repositories
  
  
• Relationship Services to obtain the relationships (such as links) associated with a document
  
  
• Versioning Services to check-out and check-in a document
  
  
• Object Services to obtain the properties of a document and create folders and documents
  
  
• Filing Services to add a document to a folder.
  

The third example use case is the ability for a SCORM-compliant Learning Management System to integrate with CMIS-compliant S1000D Common Source DataBases (CSDB) in order to repurpose technical publications content for training purposes. The International S1000D-SCORM Bridge Project is an interesting initiative to create such an integration.

In general, CMIS will enable new capabilities such as the remote access to library services, cross-repository exchange, cross-repository aggregation, and cross-repository observation (or notification).

CMIS is now supported by major CMS vendors including EMC, IBM, Alfresco, and Microsoft. A list of open source and commercial implementations of CMIS is available at this page.

S1000D and SCORM Integration

This is a presentation I gave at the DocTrain Boston 07 conference on how to reduce product lifecycle costs by integrating the S1000D and SCORM specifications.

S1000D is the International Specification for Technical Publications utilizing a Common Source Database (CSDB). Based on open XML standards, the latest issue (4.0) has been developed by the AeroSpace and Defence Industries Association of Europe (ASD), the Aerospace Industries Association of America (AIA), and the Air Transport Association of America (ATA).

Sharable Content Object Reference Model (SCORM) is a specification for online learning content developed by the Advanced Distributed Learning (ADL) Initiative.

The presentation has been updated to reflect the addition of SCORM support in S1000D 4.0.

S1000D and SCORM Integration

View more OpenOffice presentations from Joel Amoussou.

Applicability in S1000D 3.0

S1000D has a new and improved applicability mechanism based on the concepts of Applicability Cross Reference Table (ACT), Condition Cross Reference Table (CCT), and Product Cross Reference Table (PCT).

The ACT data module declares attributes of the product that are not likely to change during its life cycle such as model, series, and serial number. Examples of product attributes for a commercial aircraft include the manufacturer serial number and aircraft registration number.

The CCT data module declares technical, operational, and environmental conditions that can affect the applicability of technical content. Examples of these conditions are: service bulletin incorporation, location of maintenance, aviation regulations, temperature, wind speed, and sandy conditions.

The PCT data module lists actual physical product instances. For each product instance, the PCT specifies the values of product attributes and conditions pertaining to the product instance.

Applicability can be specified at the data module level inside the IDSTATUS or within the content of the data module at a more granular level such as a <step1> element. The ACT and the CCT are used as look up tables to lookup the relevant product attribute or condition as well as their allowed possible values. The applicability element then specifies the correct product attribute or condition identifier from the ACT or CCT and the values to test against.

The applicability information itself can be captured in human readable format for simple cases. For more complex cases, one or more assertions are used to specify the product attribute or condition to test and the values to test against. These values can be constrained with a pattern based on regular expressions as defined by the XML Schema specification.

The new S1000D applicability mechanism supports the "effectivity" requirements of civil aviation and provides capabilities that are beyond the ATA 2200 effectivity mechanism. It also facilitates the development of applicability filtering functionalties in Interactive Electronic Publications (IETPs). However, building an authoring front end that hides its complexity (regular expressions and logical operations) to the technical authors creating the content will be the key. This is also an area where well-defined business rules should be specified and enforced using a tool such as ISO Schematron.

S1000D and SCORM Integration

I gave a presentation yesterday on S1000D and SCORM integration at the Doctrain 2007 conference in Lowell, MA. The main goal of integrating these two specifications is to reduce product life cycle costs and eliminate redundancies by streamlining business processes across the documentation and training functions. I noted that there are many opportunities for data reuse at every phase of the product life cycle including: concept, design, manufacturing, assembly, testing, delivery, and support. Documentation and training belong to the support phase and are often the only departments where content is captured in XML. This is due to the complexity and cost of current specialist XML authoring tools. XForms will allow knowledge workers to contribute knowledge assets in XML at every phase of the product lifecycle with a simple web form. I also believe that Office Open XML (OOXML) offers the opportunity to extract some value out of MS Office documents by exposing their contents to XML processing languages and tools such as XSLT 2.0 and XQuery.

Engineering data should be the trusted source of data for both publications and training. For example, product model data and engineering drawings can be used to create simulation for training and manufacturing assembly instructions can be used to create installation procedures for publications. Any data reuse strategy should look beyond training and publication to identify ways to reuse data and streamline processes across the entire product lifecycle.

The integration of SCORM and S1000D presents management and technical challenges. Since training and documentation are often two separate functions within the enterprise, the integration can have an impact on budget, processes, roles, and the organizational structure. For example, the cross-functional integrated project team is a good approach. The success of the integration will also require top leadership commitment and support. It is also important to address technical challenges such as the integration of existing content management systems (CMS) and learning management systems (LMS).

The first technical approach is to create dual purpose data modules (DMs). I highlighted the importance of clearly defining and documenting business rules, particularly for dual purpose data modules. The business rules should specify among other things the appropriate level of granularity and language style (e.g. Simplified English). These business rules should be validated with technologies such as ISO Schematron and Simplified English Checkers. Since S1000D is weak on learning content metadata, the IEEE Learning Object Metadata (LOM) specification should be used to add learning object metadata to the S1000D dual purpose DMs. It is also possible to package all training data modules as a training publication module (PM). XSLT is then used to transform the S1000D DM into SCORM sharable content objects (SCOs) and learning assets. The S1000D metadata (IDSTATUS) shall be retained in the result SCOs to facilitate product applicability filtering when the SCOs are presented to the learners with an LMS. The S1000D PM can be used to generate the SCORM manifest as well. The dual purpose S1000D DM approach does not always support complex learning interactions and good instructional design principles.

The second approach is to give complete freedom to the instructional designer to design an effective learning experience. All elements in the S1000D data modules that are reusable in SCOs are assigned a unique ID. Examples are: paragraphs, steps, warning, cautions, notes, tables, etc. This can be done automatically using the XSLT generate-id() function. The instructional designer then searches the CSDB to find and display relevant DMs. She can then use XInclude/XPointer to include reusable elements from the DM into the SCO. When this is done, the SCO is automatically updated when the DM is updated.

Future versions of the S1000D specification will incorporate change proposal forms (CPFs) that will facilitate the integration of SCORM and S1000D content.

A copy of my presentation is available here.

Guidance for the Paperless Cockpit

One of the interesting applications of the Electronic Flight Bag (EFB) is electronic documents. Electronic documents allow aircraft operators to amend manufacturer’s flight operations manuals based on operator's policies and procedures and publish these manuals in electronic formats such as Adobe® Portable Document Format (PDF) and XML. Examples of these manuals are:

• Flight Crew Operating Manual (FCOM)


• Quick Reference Handbook (QRH)


• Flight Crew Training Manual (FCTM)


• Minimum Equipment List (MEL)


• Fault Reporting Manuals (FRM)


• Weight and Balance Manual


• Dispatch Deviations Guide

US Federal Aviation Administration (FAA) Advisory Circular (AC) 120 76A “Guidelines for the Certification, Airworthiness, and Operational Approval of Electronic Flight Bag Computing Devices” specifies the design and technical criteria for the approval of the human/machine interface of EFB systems. The following is an excerpt of the EFB Operational Evaluation and Approval Job Aid used by FAA inspectors for electronic documents functionalities:

• Is there a training program on how to display and interact with electronic documents? Is it adequate?
  
• Can the crews find the material they are looking for?
  
• Is the information organized in a way that makes sense to the crews?
  
• Is the information arranged in a consistent way on the screen so that the crews know where to look for specific types of information?
  
• Is it obvious when text is out of view? Is it easy to bring that text into view?
  
• Can the crew tell where they are in relation to the full document?
  
• Can the crew tell where they are in relation to the section of the document they are currently viewing?
  
• Is the text of the document easy to read on the screen?
  
• Is white space used to separate short main sections of text?
  
• Is high priority information especially easy to read?
  
• Are tables readable and usable?
  
• How are especially long and complex tables handled?
  
• Are figures readable and usable?
  
• Can the entire figure be viewed at one time?
  
• Can the crew zoom in to read details on the figure?
  
• Is it easy to move quickly to specific locations (e.g., to the beginning of a section, or to recently visited locations)?
  
• Are active regions (e.g., hyperlinks) clearly indicated?
  
• Is it easy to move between documents quickly?
  
• Is it easy to tell what document is currently in view?
  
• Is there a list of available documents to choose from?
  
• Can crews search the document electronically?
  
• Is the search technique adequate?
  
• If animation is supported, does the crew have adequate control over it?
  
• Can the crew start and stop the animation as needed?
  
• Is there a text description of the animation that describes its contents (so the crews know its contents without running the segment)?
  
• Is printing supported? If so, is it adequate?
  
• Can crews select a portion of a document to be printed?
  
• Is the hard copy usable?
  
• Can the crew terminate a print job immediately, if necessary?
  

These criteria have been developed as the result of research into human factors in the use of electronic documents in EFBs by the Human Factors Division of the Office of Aviation Programs at the Volpe National Transportation Systems Center. Knowing these criteria in advance can help an aircraft operator in preparing for approval. However, I believe that operators can benefit from a more detailed set of specifications in regard to the interface to electronic documents. Section 6.3.1 of the S1000D standard provides rules and guidance for the look and feel, and printed output from an Interactive Electronic Technical Publication (IETP). Section 6.4.1 defines a functionality matrix for IETPs to be used as an aid for defining requirements for S1000D projects. The functionality matrix leverages the US Department of Defense (DoD) long experience in defining class 1 to 5 IETMs with military specifications MIL-PRF-87268 and MIL-PRF-87269. For example, in the area of searching, the S1000D functionality matrix provides very detailed guidelines that go beyond the simple criteria "Can crews search the document electronically?" and "Is the search technique adequate?". The matrix breaks down searching functionalities into:

• Full-text search
  
• User-defined Boolean search
  
• Search across multiple databases and files
  
• Context search
  
• Keyword search
  

Publishing EFB electronic documents in XML provides many benefits over the Adobe® PDF format. Key enabling technologies for XML-based EFB electronic documents are: ISO Schematron, XSLT, XSL FO, XLink, XPointer, XInclude, and XQuery. For quality assurance, the electronic documents application should be subjected to rigorous unit testing and functional testing before its release to flight crews. A content management system can help an operator by providing features such as workflow routing, versioning, document locking, access control, and full audit trail of modifications made to documents.

The Air Transport Association (ATA) has adopted S1000D as the next generation aircraft digital data standard and there is already a very close collaboration between the ATA and the S1000D TPSMG to harmonize commercial aviation technical data requirements with S1000D. That collaboration should be extended to electronic documents for EFBs to allow aircraft operators to leverage and influence the development of the S1000D IETP functionality matrix for better guidance on creating the paperless cockpit.

S1000D Business Rules

Having been involved in the exchange and use of digital publications in the aerospace industry during the last ten years, I realize the importance of specifying well defined business rules and most importantly validating the XML documents against those business rules.

The S1000D TPSMG is currently reviewing two Change Proposal Forms (CPFs) that will help S1000D implementers in the area of business rules:

• CPF-2007-048DE: Business Rules (BR) Categories and Layers
• CPF-2006-033CA: Schematron for Business Rules

CPF-2007-048DE (written by Victoria Ichizli-Bartels and Mike Day) has proposed the breakdown of business rules into 10 categories as follows:

1. General business rules
2. Product definition business rules
3. Maintenance philosophy and concepts of operations business rules
4. Security business rules
5. Business process business rules
6. Data creation business rules
7. Data exchange business rules
8. Data integrity and management business rules
9. Legacy data conversion, management, and handling business rules
10. Data output business rules

CPF-2007-048DE also proposed the layering of S1000D business rules and will help implementers in creating a comprehensive and well organized set of business rules for their projects.

The second CPF, CPF-2006-033CA (proposed by myself and accepted for inclusion in S1000D 3.x) suggested ISO Schematron as the mechanism for exchanging and validating S1000D documents against business rules. While ISO Schematron cannot validate all S1000D project specific business rules (e.g. verifying that a paragraph is written according to the rules of Simplified English), it can certainly do an excellent job at providing very valuable reports and diagnostics information about the content of an XML document.

ISO Schematron declares assertions about arbitrary patterns in XML documents and then reports on the presence or absence of these patterns. Schematron schemas use XPath for specifying the node that is the subject of the assertion and for testing the assertion itself.

Very complex assertions can be expressed by using new XPath 2.0 constructs such as regular expressions, conditional expressions, sequence expressions, type expressions, and the extensive function library.

Today, the combined validation power of XML Schema and ISO Schematron and the query and data manipulation capabilities of XQuery have made the maxim "The document is the database" a reality.

S1000D Core

The lack of extensibility in S1000D is cited as one of its main drawbacks and could be a deterrent to potential adopters. The main strength of the Darwin Information Typing Architecture (DITA) as compared to S1000D is its extensibility mechanism referred to as specialization.

One of the benefits of DITA specialization is that it not only allows users to extend the vocabulary to satisfy their unique needs, but it also enables the reuse of processing code (e.g. XSLT stylesheets) across specializations through a fall back mechanism to base types. The DITA specialization mechanism uses an elaborate scheme based on DTDs and XSLT 1.0.

S1000D should learn from DITA’s experience and success by providing an extensibility framework that allows any party to add extensions that are needed to satisfy their unique requirements. An S1000D extensibility framework will also reduce the number of Change Proposal Forms (CPFs) submitted to the TPSMG by allowing organizations and communities of interest to adopt S1000D without "polluting" the S1000D core specification.

The combination of XML Schema’s element substitution and type inheritance coupled with XSLT 2.0 schema-aware processing facility can provide a more robust extensibility mechanism for S1000D.

Efasoft has submitted a CPF (CPF_2007-006CA ) to the TPSMG to evaluate and implement such a framework.