Maintaining up-to-date, easily accessible technical information is one of the aerospace industry's greatest challenges. One solution to this problem-and one already being used by US Airways-is Arbortext's (www.arbortext.com) XML-based publishing software. Like the better-known HTML, XML (extensible markup language) is used to create information that can be published to many different formats, including print, web, CD-ROM/DVD, and via wireless devices. However, whereas HTML merely defines what the information should look like, XML defines the information itself. For example, XML fields can dictate the type of aircraft the content is being created for. This means information about a particular aircraft can be created and published as requested by maintenance personnel.

For aerospace companies, Arbortext does the hard work of integrating legacy documentation into XML and helps companies create, manage, and publish the information. The result? The data is readily accessible in a customized, user-friendly format for mechanics and other users. In addition, using XML results in better-organized, consistently formatted data and provides a clear process for adding new information to a centralized MRO database. To date, US Airways has used Arbortext software to create an easily managed, updateable, and searchable database for its maintenance technicians. Boeing has also chosen Arbortext to produce its aircraft operation manuals; in part because XML makes it easy to generate detailed documentation on the fly.

Cessna Adopts Arbortext to Make Manuals

In a bid to streamline the creation and publication of its manuals, Cessna Aircraft Company has adopted Arbortext's XML software. Short for extensible markup language, XML works much like HTML to format information for publication to print, CD-ROM/DVD, wireless, or the web. However, because XML defines what each field is about, rather than what color or typeface it uses (as is the case with HTML), producing commonly-formatted documents is relatively painless and quick with XML.

"We have found the Arbortext software, with its outstanding XML support, to be ideally suited to help us create, reuse, and automatically publish our information," said Russ Lowen, Cessna's project leader for technical publications.

"The solution we are implementing will enable us to more easily and efficiently create and publish content that is accessible, accurate, and complete," he added. In future, Arbortext will include the ability for end users to comment and even correct the manuals they receive, and for those comments/corrections to be easily updated by the OEM.

Cutting Costs with Data Mining and Anticipatory Maintenance

Experience tells you that when a failed filter is discovered in a specific engine, the pump it protects is more likely to fail down the road. The problem is determining how likely this future failure is and whether it justifies replacing the pump or leaving it alone.

But what if you could prove that 40 percent of these pumps die three weeks after filter failure, compared with 5 percent of these pumps in properly filtered environments? Then you could make an informed decision on whether to replace the pump when the engine is already accessible or to wait until later. You could even compare the costs of fixing it immediately versus the expense of unexpected repairs and aircraft downtime, and let the aircraft's owner decide what to do.

This is the logic behind Affinity Data Mining, as offered in Exclusive Ore's (www.exclusiveore.com) XAffinity Anti-cipatory Maintenance software. Called XAAM for short, this software "mines" an airline or MRO's database looking for patterns in parts failures and how likely they are to happen.

"We base our mining on only three columns of data," explained Rob Gerritson, president of Exclusive Ore. "All we need is an identifier (either an aircraft or engine ID), a part code that identifies the part that failed and was replaced, and a date that indicates when the repair was done."

This may not sound like much to go on, but it is enough for XAAM to determine the probability of a given pump stopping after the filter protecting it has failed and to compare that probability with the pump's normal failure rate. Divide the first probability by the second-in this case, 40 divided by 5- and you have what is known in data mining terms as the lift.

"The lift value-in this case eight-helps us determine what we call the surprise factor," Gerritson said. "Basically, the higher the lift value, the higher the probability that the pump will fail in the future. The items with the highest surprise factors are the ones that MROs and owners want to know about before something happens."

Once the person responsible for an aircraft knows that a related part failure is likely, they can decide whether to perform anticipatory maintenance or not. To aid the decision, XAAM compiles probability-based recommendations on how likely a part is to fail and when. It can even compare the cost of anticipatory maintenance repairs versus unexpected repairs later on, when the aircraft might be broken down at a far-off airport.

The beauty of XAAM is that it uses hard data to provide managers with informed options. They still get to choose depending on their priorities and resources, but at least they can decide using facts and not hunches.

On a longer-term scale, the failure patterns detected by XAAM can also be used to improve aircraft maintenance schedules and routines. They can also determine what kind of failure relationships these patterns represent. For instance, a pump failing after its filter fails is a downstream incident. Meanwhile, if the remaining landing gear brakes regularly show excessive wear after an initial brake pad failure, it indicates that a full brake check is necessary in these cases. Finally, if an unrelated item tends to fail when another part is replaced, it may signal that contamination is occurring during the repair process. One thing is certain: assuming that an airline/MRO has its historical repair data available to mine, Exclusive Ore's XAAM can use this data to help develop more timely, cost-saving anticipatory maintenance practices.

"The challenge is that airlines haven't stored much of their parts' histories in computer databases," Gerritson noted. "As well, many of the databases that do exist are filled with errors, or aren't accessible by third-party programs. In these cases, we have to start from scratch, or use data on the same parts acquired from other sources."

Exclusive Ore's XAAM program costs $75,000 in its basic form and runs on Oracle, Microsoft, and IBM platforms. Boeing is the first aerospace company to adopt it for widescale use.