Classes of IETM: a detailed breakdown
Technical manuals have a long history and have been published in many formats over the years, starting from physical paper copies produced in printing presses. However, when it comes to talking about manuals for large machines such as aircrafts, it must be noted that they required thousands of pages of literature that occupied a lot of space due to the vast number of highly complex parts that they are comprised of.
With significant technological advancement, these have been progressively replaced by various forms of electronic versions: from Simple PDFs, to user-friendly “Interactive Electronic Technical Manuals” (IETM).
The Benefits of IETM
Both for those creating the manuals and for those consuming them, the conception of IETM had many benefits. The idea that a manual could be electronic means that there is increased diversity in how the manual can be viewed; rather than physically, they are able to be viewed on many devices such as smartphones, computers and tablets, making them portable as well. Due to this, they also have highly usable interfaces with detailed tables of content that are hyperlinked, so any information can be easily found without having to navigate chronological pages in physical form.
Thus, the IETM strayed away from page-oriented manuals, and was instead navigated by what information is needed; as consumers access manuals for different reasons and often need to access information fast, this proved to be far more useful. A final but key benefit of IETM was the ability to record the history of changes made to the manual; manufacturers are required to make updates and republish manuals frequently, and the IETM approach made this very easy.
S1000D
It is important to consider where S1000D comes into this as a prevalent standard. S1000D is a specification for the production of technical publications, which defines IETP as a set of information required for the description, operation and maintenance of a product. Prominent since the 1990s, S1000D uses the term IETP (Interactive Electronic Technical Publication), and never refers to IETM. IETP has been formatted for an interactive presentation on an electronic display.
Classes of IETM:
IETM systems and how they have evolved over time can be broken down into five classes which represent how technology has advanced over the years to the kinds of manuals we would expect to see in this day and age.
Class I
Class I refers to manuals that were created in the form of printed books with scanned page images before the technology was available to create them from scratch on a computer. From the scanned pages, indexes and tables of contents were hyperlinked to specific parts of the document so that the relevant information could be found more easily. These kinds of manuals would still follow the chronological order of the pages, as if they were a physical paper manual.
Class II
In class II, the manuals were still page-oriented and followed a chronological order, where the pages in PDF format included cross-links. These manuals used hypertext links that took the user to other areas in the document, making the manuals in this class easier to navigate for relevant information. Multimedia was able to be used in this kind of manual, where it could not be added in the scanned pages of Class I.
Class III
In Class III, this is where we began to see more of the free-flowing format that we might associate with electronic manuals today, rather than individual ‘pages’ (scanned/ typeset and presented in PDF format) found in previous classes. These large data sets still followed the order of the content in the manual with a high focus on creating hyperlinks using SGML/XML and viewing the content in a browser. It was possible to print these documents too, however, there would be no correlation to the way the printed content looked from the visible formatting on the screen.
Class IV
This kind of IETM was specifically made to be viewed electronically, and was ‘data driven’, meaning that the data was stored in a database thus removing data redundancy. Data was presented in a ‘relational’ manner accessed through hyperlinks tagged using SGML or XML. Class IV specifications moved away with the concept of a static page, and focused on content to be presented dynamically based on user specific needs. A big advancement based on how technology (the world of computers, devices, electronic + online content publishing) was evolving.
Class V
In this final and most advanced class, it was intended that the output would be integrated with expert systems that could display a combination of differing content sets in some sort of self-learning system. Maybe, similar to the approach used in Google search, where search results improve over time based on a large number of queries & searches entered by users.
The 5 classes of IETM as described above were created by the US DoD way back when the PCs were still not very common in the market. It was a futuristic approach considering how the manuals would/ could be made interactive. This is evident from the fact that they left the details of the interactivity of Class 5 very vague.
But in the nineties S1000D came into existence and changed the game. It took the interactivity well beyond the 5 classes, and more importantly created a landscape that would reshape how the industry would not only create a good interactive manual, but also utilise the specification for collaborative working.
Large, complex and expensive equipment are not designed by one single agency; multiple agencies need to function together for all aspects of the equipment life cycle – design, production, assembly, maintenance, repairs and overhauls. S1000D makes this collaboration easier.
IETM Classes Vs S1000D
In conclusion, it may be noted: Today the same US DoD has trashed the 5 classes of IETM that they defined and adopted the more comprehensive and futuristic S1000D. As a result, it can safely be stated that it is time for all agencies and manufacturers of complex mechanical equipment to transition to S1000D – the future is here.