Mainframe Migration Case Study
/ / Property Firm Migrates from Mainframe to Windows, Cuts Costs 60 Percent, Ups Speed
Overview
Country or Region: Sweden
Industry: Professional Services—Real Estate
Customer Profile
Stockholmshem, one of the biggest housing companies in Sweden, is based in Stockholm and has 340 employees.
Business Situation
The company wanted to replace an aging mainframe that was costly and difficult to maintain.
Solution
After considering a move to UNIX, the company chose to migrate its existing COBOL code to servers running the Microsoft® Windows Server® operating system.
Benefits
n Cuts maintenance costs by 50 percent
n Boosts performance 1,000 percent
n Increases developer productivity
n Enables platform consolidation
n Facilitates integration with new customer service solutions / “With the Windows-based solution, Stockholmshem is enjoying more performance than it could afford on an updated mainframe, and much more performance than it saw on its legacy mainframe.”
Kjell Hassel, Project Manager, EDB
Stockholmshem, one of the largest residential management companies in Sweden, needed to replace a legacy mainframe that was costly and difficult to maintain. A move to UNIX was considered but rejected in favor of a migration to servers running the Microsoft® Windows Server® operating system to take advantage of the cost-effectiveness and flexibility of a Windows® solution. With multiple mainframe-to-Windows migration paths available, Stockholmshem chose the one that reflected its priority to minimize risk and cost—so it was able to preserve its COBOL code, reducing the development burden and need for employee retraining. Stockholmshem avoided an expensive mainframe upgrade, reduced maintenance costs by 50 percent, increased performance by 1,000 percent, and gained the ability to easily integrate new solutions into its environment.
Situation
Stockholmshem, one of the largest residential management companies in Sweden, wanted to maximize its return on investment in its technology system while minimizing risk. This was important to Stockholmshem because the company is wholly owned by the City of Stockholm and thus answerable to its citizens. The company rents housing to about 8 percent of Stockholm’s residents and sees revenues of about 1.8 billion Swedish krona (about U.S.$250 million) per year.
One investment that had served Stockholmshem well was the real-estate software system it used to run most of its business, including the processing of all customer data, residential unit data, invoicing, and service requests. That system, which ran on a Hitachi EX33 mainframe, was created in 1963 and had been expanded over the years to include roughly 170 online Customer Information Control System (CICS)/COBOL programs and 370 batch COBOL programs. The data was stored in a hierarchical DL/1 database and in virtual storage access method (VSAM) files.
Approximately 250 of Stockholmshem’s 320 employees relied on the system to do their work, with about 50 employees using the system at any one time. The solution had been created for Stockholmshem by Microsoft® Certified Partner EDB, which continued to host and manage it.
By 2002, however, the mainframe system was showing its age. It was expensive to maintain and would have been even more expensive to upgrade. The mainframe development environment made change slow and costly, so application enhancement and new application development couldn’t keep up with the company’s needs. Worse, Stockholmshem was one of just six companies in Sweden continuing to run the VSE operating system. The vendor ecosystem—the pool of vendors available to service the environment—was, as a result, also shrinking. Resources to maintain the solution became increasingly scarce and expensive. “There weren’t enough customers running this software,” says Kjell Hassel, Project Manager, EDB. “That was a major continuing risk.”
Performance was also an issue, with the system sometimes unable to complete batch processes during the nightly batch time periods. The IBM-based environment also was difficult to integrate with the rest of Stockholmshem’s infrastructure, which ran largely on Windows®-based technologies and the Microsoft .NET Framework, an integral component of the Windows operating system that provides a programming model and runtime for Web services, Web applications, and smart client applications. The company’s Web portal for customers, for example, had been created using .NET software. The hardware, software, and personnel costs of maintaining multiple computing platforms were a further drain on the company’s resources.
And it wasn’t just the company’s mainframe that was aging—so was the staff needed to run it. The average age of the support personnel for the system was over 55 years. With those people headed toward retirement, Stockholmshem needed a younger generation of developers and technicians to replace them but “COBOL isn’t the technology that younger people are flocking to,” notes Allan Hansson, Information Technology Program Manager, Stockholmshem.
Stockholmshem and EDB executives got together and considered their alternatives. They considered a total redesign or rewrite of the system in a new environment, but rejected that as too costly and risky. Finding an off-the-shelf system, or buying and modifying a system already in use by another real-estate company, would have been cost-effective but an appropriate solution couldn’t be found. Some type of system migration was the logical choice—but migration to what?
Solution
In 2002, Stockholmshem decided to migrate its system to a UNIX-based platform. “We didn’t see many models for migrating from the mainframe to Windows,” says Hansson. “UNIX seemed the appropriate choice.”
The first step in that migration was converting the DL1/VSAM data into a relational database, while keeping it on the mainframe. To maintain the flexibility to support future system enhancements, Stockholmshem and EDB decided to create bridge programs to intercept the DL1 and VSAM calls from the legacy programs and convert them on the fly to access to the relational database. This part of the solution was completed by December 2003. Then, the development team discovered that the hardware needed to support the new database was an impractical investment.
Deciding on a Windows-Based Solution
The team reconsidered its options, including moving directly to another platform. Since Stockholmshem’s initial planning, Microsoft had released its Microsoft Windows Server® 2003 operating system and an increasing number of companies had implemented migrations from the mainframe to Windows, based on the performance and cost-effectiveness of Windows-based systems compared to mainframe and UNIX alternatives.
“When we saw there were good alternatives for us on the Windows side, we became more interested in that direction,” says Hassel.
Still, Stockholmshem and EDB were concerned about the availability that a Windows-based solution could deliver, given the business-critical nature of the real-estate system to Stockholmshem and the impression they had that a Windows-based solution would provide lower availability than a mainframe-based solution. The companies conducted a test of the migrated solution and were pleased with the results.
“In our test, the Windows-based solution delivered all the availability we wanted,” says Hansson. “We felt pretty safe.”
Implementing the Migration
The decision to migrate to a Windows-based environment was made in April 2004 and development work was completed in December of that year. Stockholmshem and EDB then prepared for production, including conducting more than 200 tests to ensure that all of the business processes performed correctly in the migrated environment. The actual cutover between systems was completed over a weekend in March 2005.
Stockholmshem and EDB put a priority on minimizing the time and effort of the migration, so they wanted to maximize the use of Stockholmshem’s existing COBOL code base. Accordingly they chose to migrate the CICS/COBOL applications into a native Microsoft ASP.NET solution, rather than rewrite the entire solution. The migrated solution runs on Windows Server 2003 with Microsoft SQL Server™ 2000 as the database.
The companies created three hardware environments for the solution, one each for development, acceptance testing, and production. Each environment consists of three Hewlett-Packard DL380 dual-processor computers, one each for the database, domain controller, and applications.
The key development tools for the migration were the Microsoft Visual Studio® .NET 2003 development system and the Fujitsu NeoKicks migration toolkit.
Figure 1 shows the migration process:
n The 3270 screen layouts are processed by a map processor, where they are converted to XML-formatted description files. The XML files are converted to ASP.NET Web pages that include code written using the Microsoft Visual C#® development tool.
n COBOL source code is processed in two steps: first by a preprocessor to divert all DL1 and VSAM calls to bridge programs and, second, by the NeoKicks preprocessor to route all CICS calls to the NeoKicks Services class library.
n Configuration information, such as transaction codes and program mappings, are transferred to the web.config file in ASP.NET with the help of a NeoKicks wizard.
After migrating existing COBOL code to the Windows-based environment, the developers began the continuing process of integrating the real-estate system with other applications. For example, they’ve used .NET–connected Web services to integrate the system with the Stockholmshem customer Web site for registering for new housing.
Benefits
As a result of the migration:
n Operating costs were reduced by 50 percent
n Performance was increased 1,000 percent
n Developer productivity was increased 50 percent
n Scalability and flexibility increased, so Stockholmshem can integrate the real-estate system with other solutions, boosting the company’s agility and customer service
Cuts Costs by 50 Percent
The migration of its real-estate system software from a mainframe to Windows-based servers has cut costs to Stockholmshem by 50 percent. As a result, Stockholmshem is paying consultant EDB just half of the fee it formerly paid for the hosting and maintenance of the solution and expects full return on its investment in two-and-a-half years. “The savings from migrating to Windows is really great,” says Hansson.
One key area of savings is software licensing costs, which are far lower for Windows-based software than for the legacy mainframe software. The second key area of savings comes from the maintenance of the Windows-based environment, where EDB estimates that it is up to 50 percent more productive than before, enabling it to pass along the savings to Stockholmshem.
“We’re seeing this savings without any reduction in quality of service,” says Hansson. “Our Windows-based solution has redundant power and storage, and full backup and supervision. It just costs less than the mainframe.”
Boosts Performance 1,000 Percent, Provides Room to Grow
The Windows-based solution doesn’t just deliver comparable performance for lower cost—it delivers superior performance for lower cost. Benchmark testing on the solution shows that it delivers throughput that is 10 times the rate of the mainframe solution. Overall performance is the equivalent to a 100 MIPS mainframe, according to Hassel, with total transactional capability of about 350 transactions per second.
“With the Windows-based solution, Stockholmshem is enjoying more performance than it could afford on an updated mainframe, and much more performance than it saw on its legacy mainframe,” says Hassel. “This is a very important advantage. It means that batch processes can be completed within their allotted overnight time periods. We no longer get the spillovers that affect availability in the mornings. The new, Windows platform is more scalable than the mainframe. It means that there is room to grow the solution and to add additional applications that leverage the existing investment.”
Increases Developer Productivity up to 50 Percent
The Microsoft visual development environment reduced training costs and improved development productivity significantly over the 3270 text development tools of the mainframe, according to Hassel, further lowering the cost and enhancing the value of the solution. Developer productivity on the new solution is up to 50 percent higher than on the legacy mainframe.
To prepare for the migration, the developers participated in one week of training on Visual Studio, SQL Server, and the .NET Framework.
“Our COBOL programmers were able to implement the migration with relatively little training for the new environment,” says Hassel. “The fact that they were able to retain and work with their existing COBOL code made the process much smoother and easier than it would have been otherwise.”
Just as Stockholmshem chose to minimize the up-front cost of the migration by retaining its COBOL code and making only a basic migration to new hardware, it also retains the option to continue its development efforts at its own pace.
“The most important benefit is the ability to modernize the migrated system in small steps,” says Hassel. “The large, monolithic system has been broken up into smaller units—the formal term is ‘functional decomposition’—that can be enhanced piece by piece as Stockholmshem sees fit, in response to its evolving needs and market conditions.”
The developers also used this step-by-step approach to minimize the impact of the migration on Stockholmshem employees, as a way to minimize cost and risk. For example, they retained the mainframe screens, rather than creating new screens that took advantage of the greater graphical capabilities of the Windows-based environment, in order to eliminate the need for employee retraining and to increase the likelihood that critical functions, such as invoicing customers, would continue seamlessly in the new environment.
“Because we’re a publicly owned company and because an error in invoicing to our customers could have been catastrophic, we put a premium on reducing risk,” says Hansson. “Happily, the migration gave us the option to proceed in a way that addressed this concern.”
Enables Platform Consolidation
EDB and Stockholmshem anticipate further gains from the solution as they reap the benefits of consolidating on the Windows platform. Much of Stockholmshem’s other infrastructure is already Windows-based and migrating the real-estate system to that same environment eliminates the need to maintain separate staffs for development and administration. Stockholmshem will also benefit from a companywide consolidation in computers, data storage, and the number of maintained products.
Facilitates Integration with New Customer Service Solutions
Beyond reducing the cost of maintaining the real-estate system, the migration to a Windows-based environment has enabled EDB to extend that system for Stockholmshem in ways that boost productivity, agility, and customer service and satisfaction.