In this section, we briefly look at the flow through the EPS application from the user's perspective. In the next section, we delve into the actual development of the EPS.
Figure 12-3 shows a screenshot of the first page of the EPS application. This static HTML page, generated by the EPS.html file, is the main form in which the user enters information about the component to be procured. In the screenshot, information for part number 15151, desired quantity of 4, and optimization criteria of lead-time are specified.
Figure 12-3. Screenshot of the first page of the EPS application that is generated by the EPS.html file.
The EPS.html form page also provides a hyperlink labeled "Browse the Catalog" that presents to the user the component catalog as shown in Figure 12-4. The EPS component catalog displays the vendor names, the component part numbers they carry, and a brief description of each component.
Figure 12-4. Screenshot of the EPS application component catalog that is generated by the EPSCatalog.html file.
Based on the information entered into the EPS.html form, a response page is generated by the OutputServlet. For the form data entered as shown in Figure 12-3, the corresponding response page is shown in Figure 12-5.
Figure 12-5. Screenshot of the results page that is generated by the OutputServlet based on the user entering part number 15151, quantity 4, and optimization metric lead time.
As we have seen from the screenshots, the EPS application provides a simple Web-based interface for procuring components from multiple, competing vendors. Given the desired part number and the optimization criteria, the program compares the prices and lead times from the various vendors and reports the best vendor back to the user. Web services facilitate the development and maintenance of this application as any component vendor that provides a Web service for their inventory and ordering processes can be utilized by the EPS application. By virtue of it using Web services, the EPS is not a proprietary system capable of only communicating with vendors A and B.