Automated Purchasing and Supplier Data Integration with XML

July 28, 1998

The Business Problem
The Role of XML
Solving the Problem with webMethods B2B Integration Server, WIDL, and XML
   Situation Overview
   User Scenario
   Behind the Curtain
XML Example
Information Flow Diagram

The Business Problem

The ACME Corporation is a multi-billion dollar manufacturing company with offices and plants in over 30 locations nationwide. It is set up to be decentralized with purchasing agents at each location, but it tries to keep a tight rein over costs by centralizing acquisition management. The result is a purchasing system that is cumbersome, slow, and error-prone. Requisition forms have to be completed at the employee location, faxed to the administrative headquarters, and then often faxed to a manager for approval and signature. Furthermore, there is no automatic way to consolidate catalog information from multiple sites or electronically purchase items. Consequently, the maintenance cost of this system is very high.

The Role of XML

XML provides an efficient, flexible, and extensible means of describing data and specifying interchange formats. With an XML-aware browser like Microsoft® Internet Explorer 4.0 and an increasing number of XML-enabled applications, it is easier than ever before to build robust and flexible applications for electronic commerce.

In this scenario, XML is used to define an extensible query mechanism and to standardize the descriptions of the catalog elements that are returned by the query. XML also makes it possible to retrieve very precise results. After catalog items have been selected, XML provides the mechanism for specifying all the parameters in the purchase order. XML is also used as the basis for Web Interface Definition Language (WIDL) from webMethods (http://www.webmethods.com/ ). A WIDL is a specification that (in this case) describes which portions of data are to extracted and manipulated by the webMethods' Integration Server.

Solving the Problem with webMethods B2B Integration Server, WIDL, and XML

Situation Overview

In this scenario, the ACME Corporation has adopted a very efficient system: an automated purchasing application. With this application, ACME purchasing agents use a single user interface to simultaneously access a variety of suppliers' Web-based catalogs. They can search for items across multiple Web sites, select items, and generate a purchase order that will result in the shipment of the items directly to their location. The system also preserves ACME's centralized administration by allowing managers to remotely log in to review purchase orders submitted by their subordinates.

To accomplish this, live data from shopping sites on the Web is extracted according to the integration rules executed on the Business-to-Business (B2B) Integration Server. This Web-based procurement system illustrates how webMethods' B2B Integration Server can use XML to specify requests and format structured information that can be sent directly to Internet Explorer 4.0. Now, organizations can aggregate information from multiple Web sites, interact with those sites to conduct all forms of electronic commerce, and clearly organize and present both the information and the functionality to meet their specific needs.

User Scenario

George, a purchasing agent at ACME, needs to buy several high-speed Ethernet cards for an engineering group. He logs on to his corporate intranet and selects "Purchasing System". The URL takes him to the official purchasing page, which lists authorized vendors -- including Cyberian Outpost. He clicks the Search button and is presented with a search form that specifies various product categories. He chooses Networking Card and inputs "Ethernet". Search results from all the vendor sites are then displayed in one table. The categories include the supplier's identifier number, the product description, the price, and available inventory.

Since the data is in XML, and George is using Internet Explorer, there are many ways to browse and organize the search results. Ultimately, George selects two Ethernet cards: 3Com and Adaptec. He then clicks a button to generate purchase orders. The PO is automatically generated with both order data and data about George (his cost center and security level). He also inputs the engineering cost center and project code. He then reviews the order one last time and submits it to his manager for approval.

As soon as George's manager logs on, she sees George's purchase request along with others from the same group. She reviews the requests, drills down for more detail if desired, and accepts or denies the purchase order(s). She approves George's request and clicks on the Order button to send the order to the supplier.

Later that day, an executive Bean Counter at ACME wants to see the accumulated project expenses for the previous week. He opens a Microsoft Excel spreadsheet that contains the appropriate numbers and categories. He updates it by selecting the Update button from the customized toolbar.

Behind the Curtain

The purchasing process

The client software is Internet Explorer 4.0 or later.
The purchasing agent's choice of URL connects his browser to the B2B Integration server, which generates a dynamic page showing approved supplier sites.
An XML form containing search categories is generated from XML data stored on the local intranet. These categories were previously built using B2B Developer. B2B server can search within XML tags to get precise data and also has multithreading query functions for simultaneous searches of all the vendor Web sites. It uses the WIDL files that describe each vendor site to create the queries. The WIDLs are stored in flat files on the server or in a local database.
The WIDL works as follows: Since the vendor sites contain basically the same information but are formatted differently, the WIDL is defined for each Web site and describes how to extract data like the product description, SKU number, and price. The B2B server standardizes the format of the information before it is sent to Internet Explorer based on the specifications in the WIDL.
By responding to requests that are formatted in XML, the B2B Integration Server allows the browser to use the same language for both viewing data and making requests.
All data is returned as XML data. (If the datasource is HTML, it is converted by functionality built into B2B.) The XML snippets are then integrated into an XML document on the middle tier. It is delivered via HTTP and rendered by Internet Explorer using XSL, DHTML, and scripts.
On Submit, the server checks George's job code and executes business rules defining who can build purchase orders and for how much (and also how much a manager can approve). Purchase orders are stored on the local server (as XML, HTML, or plain text, based on preference) while waiting for managerial approval.

Manager review of purchase orders

The B2B Integration Server shows George's manager the appropriate POs based on his login. They are provided in XML, regardless of the format or structure used to store them.
The B2B Integration Server organizes the XML data from the purchase orders into a format that each Web site can understand, and launches a purchasing process specific to each site.

Accounting review of purchase orders

An XML form presents possible search categories. The B2B server searches all purchase orders generated over the specified time and combines the search results into a single XML document that is returned to the browser. Once again, a predefined XSL style sheet is used to render the XML-based results.
Alternatively, if the manager chooses to search the data from within a Microsoft Excel spreadsheet, the B2B server is invoked by an Excel-based macro. The B2B server retrieves the Purchase Order data from the local repository and takes advantage of XML to compare data within specific tags like to retrieve only the data that has changed. The Excel macro then populates the spreadsheet.

Ordering from the supplier

Before the order is sent to the supplier, Acme-specific information like the agent's cost center is stripped out to be used for other accounting procedures. The confidential data that is sent in the purchase order is protected because B2B Server maintains security via an SSL session using RSA's security algorithms and webMethods' own XML-RPC mechanism.

XML Example

<?xml version="1.0"?>
<!DOCTYPE WIDL-MAPPING SYSTEM "widl30_mapping.dtd">

<WIDL-MAPPING NAME="Outpost" VERSION="3.0">
<!-- ============================================== -->
<SERVICE NAME="Search"
INPUT="SearchInput"
OUTPUT="SearchOutput"
METHOD="GET"
URL="http://srch.outpost.com/search/productsearch.cfm"
SOURCE="http://www.outpost.com/"/>

<!-- ============================================== -->

<INPUT-BINDING NAME="SearchInput">
<VALUE NAME="query" FORMNAME="name" USAGE="DEFAULT"/>
</INPUT-BINDING>

<OUTPUT-BINDING NAME="SearchOutput">
<CONDITION TYPE="FAILURE"
REFERENCE="doc.p[0].text" MATCH="*0 matches*" REASONTEXT="No matches found"/>
<VALUE NAME="sku" DIM="1" USAGE="DEFAULT">doc.table[1].tr[].td[1].font[1].text</VALUE>
<VALUE NAME="desc" DIM="1" USAGE="DEFAULT">doc.table[1].tr[].td[2].font[1].text</VALUE>
<VALUE NAME="price" IM="1"
USAGE="DEFAULT">doc.table[1].tr[].td[5].font[1].text['\$&amp;']</VALUE>
</OUTPUT-BINDING>
<!-- ============================================== -->
</WIDL-MAPPING>