An Introduction to ISO 15926 November 2011 - iRINGToday

The rest require some interpretation:
Metric Data Sheet Imperial Data Sheet Comments
Normal Flow Capacity: Normal Probably the same
Rated Flow Capacity: Rated Probably the same
Max. kPag Suction: Max. No data entry spot
Differential Head Diff. Head: Rated Possibly the same
NPSH Available NPSH Avail.: Rated Possibly the same
Most mechanical engineers with a little experience will have no trouble figuring everything out
because they have the rest of the project documents, and perhaps have experience with the
pump manufacturer. Again, that is the point. We need humans to guide even what seem on
the surface simple transcription tasks because our work practices depend to a great degree
on context. However, when machines start talking directly to other machines the problem of
implied meaning based on context becomes a serious barrier.
The reason information exchange works these days is because we exchange entire sets of data
(for instance, a complete data sheet) in which the context is preserved. The disadvantage,
however, is precisely that: we have to exchange entire sets of data and we must have humans
interpret them item by item. What we really want is to be able to let machines exchange information
directly without having to rely on context to retain the correct meaning. What we really
need is a “cut-and-paste” tool for plant information. We want to be able to just “cut it from that
database over there” and “paste it to this database over here.” However, it’s not that simple.
The first and most obvious reason we cannot use a simple cut-and-paste tool is that the data
values we want to transfer seldom map to the same (x,y) coordinates on any two data sheets.
In order to know which data values to transfer, we have to first know enough about the data
sheets and underlying databases to know which values are required, which values can be ignored,
and whether or not something is missing.
The second reason is, as we have seen in this example, we cannot rely on the name of the attributes.
Even when attributes in two databases have the same name, we cannot be sure there
are no subtle differences in their meaning. We need a human expert to confirm that the attributes
match. These actions are trivial if you have the right context. We have many thousands
of design engineers doing this all day, every day, and generally they are good at it. However,
we rely so much on context to convey meaning that we cannot trust machines to make the
right decisions on their own.
Finally, this is all carried out in the context of the same written language. What would happen
if the project were engineered in English but the client wanted all of his data sheets turned
over in Russian?
The Value of the ISO 15926 Dictionary
When we want to exchange information between two software applications, the traditional
way is to map the respective databases together. We preserve the context by manually examining
the terms in each database to determine which are equivalent. Directly mapping two
applications together is often the easiest short-term solution.
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