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Standard Needed
In March 2002, the Information Exchange Technical Committee under
Singapore's IT Standard Committee (ITSC) initiated a project called
the XML Industrial Project (XIP). The purpose of this project is to
implement a system to assist Singapore companies to evaluate XML as
a tool for data exchange among them.
A set of documentation, which includes system specifications and E-business
documents DTD files are provided. Eight commonly used business documents
such as Request for quotation, Quotation, Purchase order, Purchase
order acknowledge, Delivery order, Invoice, Receipt of delivery, and
Receipt of payment were defined as XML documents.
It is important for us to adopt a data structure format conforming
to standard like XIP so that the data structure can be exchange with
a wider group of companies. XIP also provides guidelines on how data
are exchanged. This makes interoperability with partners easy.
The XIP project has achieved simplicity in design, allowing savvy
end-users or new developers to expand the project further. Evaluation
solutions are available for companies to download for further testing.
XIP is also designed for use with password-controlled file transfer
protocol as its transport mechanism. It is possible to extend the
XIP transport mechanism to include other transport services like HTTP/SOAP
(HyperText Transfer Protocol/simple object access protocol) which
uses XML representation, and taps on Web HTTP which is used widely.
This XIP system is easily deployable in small-scale companies that
do not have the financial nor manpower resources to run its own IT
infrastructure. It can operate on a Pentium II computer connected
to the Internet via a modem dial-up.
The suppliers do not need special hardware or software to use the
system. They only need to subscribe to a standard dial-up Internet
access account.
Many business partners already have their own business applications
in their organisation. It is easy to convert XML document data to
the data structure for the existing business application.
XML Documents
Figure 3: Sample XML Document
XML documents come with a DTD attached that helps the receiving program
make sense of the XML. For example, an XML document (Figure 3) consists
of a set of start and end tags denoted by "<" and ">"
symbols. The name enclosed within these pair of notation is the element
name and it is also called a node if it has sub-element. For example
"NoteBook" is a node. "RFQ" is also referred to
as the root node because it is at the highest level of the structure.
Additional information can be embedded within the element, for example
the element "UnitPrice" has an attribute "currency"
which tells us that it is in US dollars. This forms the structure
of this XML document
In XIP, a document titled XIP Version 1.0 DTD specification is available
at ITSC Web site. It is written for software developers and users
who need to understand the purpose of each element and attribute as
defined in the DTDs. It includes the purpose of the elements defined
and permissible values. For example, the date format is coded as "YYYYMMDD";
codes for currency and countries are defined.
For interoperability to take place, software implemented at each end
of the link must understand the syntax and its meaning so that it
can successfully extract the information for further processing.
Figure 4 shows the screen shot of the purchase order XML document.
For example in XIP, to create a purchase order it needs to be enclosed
by "<DocumentExchange>" tag with the proper attributes
defined. You can find the "PurchaseOrder" tag which marks
the beginning of the information related to the purchase order.
Figure 4: Sample of a purchase order XML document
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