Issue No 11:
IS NOT A SILVER BULLET
is NOT a Silver Bullet
AUSTRALIA – July 22, 2000:
XML previously in TEN (see http://www.ies.aust.com/~ieinfo/articles.htm#TEN).
XML offers great benefit, but it is not a silver bullet. This issue discusses
how XML can be used effectively for e-Business and for integrating structured
and unstructured data within and across enterprises through Enterprise
Application Integration (EAI). The issue also announces an Online Webcast
Seminar on XML, plus other upcoming conferences and seminars that will assist
TEN - The Enterprise Newsletter
Back to Contents.
XML IS NOT A
BUT IT OFFERS GREAT BENEFIT IF USED WELL
XML is NOT a
silver bullet. It will NOT magically integrate the many redundant data versions
that exist throughout most enterprises. It will NOT replace them with a single,
common shared version of integrated data. But it will enable us to achieve the
effect and many of the benefits of this “Holy Grail” … if we use it
correctly. Let me explain why …
XML makes it
even more imperative than ever that an enterprise must understand and resolve
the different words and meanings that it uses to refer to things important to
it. To illustrate, people may variously be called “Customers”, or
“Clients”, or “Debtors” – all terms that are used to refer to people
or organizations that buy from the enterprise. These different terms indicate
“semantic differences”. An organization must know the different meanings of
its data (as metadata) that are used throughout the business. It must then
define standard terminology - and establish agreed meaning - as integrated
metadata to be used by the enterprise. Only then can these terminology
differences be resolved so that semantic integrity is maintained.
Administrators and Consultants we were fooling ourselves if we thought that
enterprises would throw away their many (dis)integrated legacy systems to
improve semantic integrity. It never did happen; it never was going to happen;
it never will happen. Pragmatically, legacy systems and databases will never be
replaced for semantic purity alone. But once we understand the semantic
differences and agree on the integrated metadata, XML can achieve dramatic cost
savings. For example ...
was once proposed as a standard language for common communication throughout the
world. But it was never accepted. Why should people in every country have to
change from their native tongue? Each reasoned that others could change … but
not them! So we continue to have interpreters whose job is to understand several
languages. They rely on reference tools (such as language dictionaries) and
their knowledge of languages to translate between them. They use the language
dictionaries and knowledge to resolve the semantic differences. The result ...
understanding, meaning and communication!
XML. It enables the metadata "language" used by each application or
department of the business to be documented in a separate "language
dictionary". The metadata language dictionary used by each application is
documented in a XML Document Type Definition (DTD) file. This is called
“Application Metadata”. Common terminology is then defined for use
throughout the enterprise. This is referred to as “Integrated Metadata”.
semantic differences between application metadata and integrated metadata, XML
can be used to resolve between those differences. We then know that the metadata
used by the Order Entry Dept for Customer (say), and the metadata used by the
Credit Control Dept for Client (say), both refer to the same thing - common
integrated metadata of (say) "Organization". XML transformation
engines can then carry out this semantic transformation. In our language
analogy, the XML DTDs are the language dictionaries, while the transformation
engine is the language interpreter.
We must also
recognize that XML does not solve the semantic problems of legacy databases and
systems: data redundancy. The only way this redundancy can ever be resolved is
to throw out the legacy databases and systems and start again with an integrated
database. But that did not happen, and it will never happen for semantic
integrity reasons alone.
So the same
data still exists redundantly in the Customer database for the Order Entry Dept,
the Client database for the Credit Control Dept and the Debtor database for
Accounts Receivable in the Finance Dept. But now with XML these different data
versions can easily be synchronized dynamically via XML messaging. These XML
messages are analogous to the physical "Change Request Form" that was
sent to Order Entry, Credit Control and Receivables notifying them of a change
so they could update their respective redundant data versions. But now through
XML message transformation, this synchronization occurs at electronic speeds.
Yes, XML is
NOT a silver bullet. But if we identify metadata and resolve semantic
differences throughout the enterprise, we can use XML very effectively to
resolve those differences. We can use Transformation engines to transform
between and synchronize redundant data versions at electronic speeds. We can
then reap the integration benefits as if we were truly using a single shared
version of common, integrated data.
of different application metadata within departments of an enterprise is
magnified greatly when organizations communicate at electronic speeds through
Business - to - Business (B2B) Trading Exchanges. Common message formats and
integrated metadata enable clear electronic communication between buyers and
sellers. XML can be used to transform between application metadata and
integrated metadata as discussed above. This is called “Enterprise Application
savings can be dramatic. For example, typical procurement costs based on mailed
or faxed Purchase Orders often exceed $100 per PO … regardless of the actual
cost of the product being purchased. With
B2B electronic procurement using XML procurement costs are reduced significantly
to less than $10 per PO (Gartner Group). These are cost savings that go straight
to the bottom line for all concerned.
XML is not a
silver bullet. But when used well … based on agreed terminology and metadata
that is defined using data modeling methods and modeling tools … it can
deliver great cost savings and improved operational efficiency.