Mainframes and legacy systems have presented IT executives with a dilemma for much of the past decade. In the race to move IT operations to the Web in the 1990s, many companies considered dumping the aging systems altogether. Yet, these "dinosaurs" usually contained mission-critical data the companies wanted to preserve and integrate into newer Web applications, and so they survived until the dot-com implosion.

Since then, many companies haven't had the resources -- or often the inclination -- to replace mainframes and other older IT assets that hum steadily along and are the incarnation of decades of investment. Those systems still handle high volumes of transactions -- and the data they generate -- securely and reliably. This leaves IT shops searching for methods to get to the data housed in the systems so that it can be used in Web-based applications -- and they'd like to do it without rewriting code. Complicating the picture is the fact that mainframes were designed as discrete, single functions, creating problems for companies that need to give Web-based applications access to several different silos on back-end systems.

Now, with growing corporate interest in service-oriented architectures (SOA), companies are looking at using Web services to more easily integrate data from older back-end systems such as IBM mainframes and AS/400s, Unix/OpenVMS systems and Hewlett-Packard e3000s into newer applications.

For example, construction company Shea Homes is using Web services to integrate a green-screen J.D. Edwards home-construction application running on IBM AS/400 with newer enterprise applications without having to rely on hard coding.

Senior technical manager at Shea Mike Little says he integrated the older module in less than two weeks using tools from WRQ, a process he describes as "screen scraping on steroids." Writing custom code for the integration would have taken more than four months, he adds.

Seattle-based WRQ's Verastream tools are designed to expose legacy application logic as Component Object Model (COM), Java, .Net or Web services components that can then be used in Web applications or added to newer enterprise applications like CRM systems. Verastream adapters establish communications with the host system, and integration tools allow users to point and click to abstract legacy functions as components, according to WRQ.

"It is very easy to go through and set up the navigation through the screens," Little says. "They have an automated way to take what you have created and generate a Web service without generating any custom code."

Employees at Shea can now access information from the J.D. Edwards system in real time instead of waiting for batch-processing jobs to run. And the Web services can be reused, Little says.

For example, the service that contains data needed for a sales application can be used later in an accounting spreadsheet. The company, which runs up to 50,000 transactions per day to gather data from the J.D. Edwards system, has had no performance problems with the integration, Little says.

Ensuring accuracy
Electric Insurance Co. in Massachusetts is using technology from Neon Systems to help integrate data from its IBM CICS Transaction Server to a spreadsheet application that allows its call centre employees to provide customers with real-time insurance-policy quotes.

Neon's Service Builder product wraps queries from call centre agents as Web services, delivers them to the CICS server and returns replies as Web services, says Steve Coyne, data warehousing specialist at Electric.

The company also needed a way to easily get discount information and data related to various state regulations from the mainframe to the spreadsheet application. Neon's technology creates an abstraction layer to the mainframe data, evokes the data as a Web service and delivers it to the spreadsheet.

In the past, Electric Insurance used a Cobol program to build in rates. Several people, including pricing analysts and quality assurance workers, would have to open the program and build in rules to determine rates, says Coyne.

Electric first used Neon's technology in 2003 for personal umbrella policies and then added it to generate home-owners' insurance price quotes. Now, the company is rolling it out for policies for General Electric Co. employees, Coyne says. "You're constantly battling other insurance companies for rates, [and] this allows the pricing department to be able to introduce a rate change or a discount quicker," he says.

Escaping code history
Using Web services to access data and logic from mainframes and legacy systems can often drastically reduce the time needed to integrate data into new applications, because the technology can abstract the data without requiring developers to navigate through multiple screens or sift through multiple customisations to rewrite code.

Global Home Loans Ltd., a subsidiary of Countrywide Financial, used WRQ technology to slash development time to six months for an integration project that, according to the company, could have taken three to five years.

Global needed to integrate the mortgage-processing systems of Barclays Bank with its own systems when Barclays outsourced loan processing to Global, says James Pierce, chief technology officer of Countrywide's global markets division.

Using Verastream, Global built a Web service interface to Barclays' mainframe to allow Global's call center to service Barclays customers, Pierce says. The bank built this abstraction layer in front of the legacy system using WRQ tools to evoke data from the mainframe as Web services that can be passed to call centre representatives.

This approach allows the company to service customers while it moves the Barclays origination and processing systems in smaller increments to its own core platform, he adds. "We were able to get to the legacy system and put in one call-centre-type interface and allow one source of entry for various transactions on those systems," he says. "That gave us several years of ROI and an incremental strategy [for the Barclay's integration], which is more successful than a big-bang effort."

This ability to "migrate while you operate" is what makes Web services so attractive to companies that need to fold data on legacy systems into applications as they gradually move to newer systems, says Phil Murphy, an analyst at Forrester Research.

"Folks are finally realising that to replace systems that took 25 to 30 years to build ... will take decades," Murphy says. "With Web services, you can deliver business value immediately. As that money comes rolling in, it can be earmarked for the true infrastructure changes that may be needed down the road."

Potential pitfalls
Murphy notes, however, that some mission-critical mainframe applications that require responses in real time won't be able to take advantage of exposing data as Web services.

"If you need 100 gazillion transactions per second, nothing but the most highly architected solution is going to work for you," Murphy says. "But in virtually every company, at least 50 per cent of the applications don't need that level of speed -- especially for the self-service kind of applications."

In addition, integrating legacy data with Web services interfaces can create other problems for businesses, says Ron Schmelzer, an analyst at ZapThink. While most companies can usually cut integration costs by half with Web services, they may still have data-transformation issues, he says.

"Even though we can get to the mainframe, we still have not solved the problem of one application that calls a purchase order one thing and the mainframe calls it something else. I still have to solve the data-transformation issue," says Schmelzer. "We're moving the cost from managing the interface and the connection to managing the data."