Modernizing and extending your COBOL

Open System Application Modernization

Extending your COBOL applications running under Windows, UNIX, Linux and zLinux

While modernization provides a low risk cost-effective way to deliver new business functionality fast, a decision for modernization may have been preceeded by a reuse or rewrite discussion. The pressures to re-write or replace your COBOL systems are often due to a lack of awareness or understanding of the options available to extend your COBOL applications to meet today’s business needs. However, for Micro Focus customers who have already employed many of these options, the concept of "modernizing your COBOL applications" often provokes a negative response because it implies their COBOL applications are not already modern or contemporary.

This is understandable if you consider that such companies have evolved their applications to:-

• A sound architecture with user interface, communications, business processing and data access layers which are all well defined
• Adhere to structured programming guidelines to improve maintainability and provide core business functions as callable modules
• A Service Oriented Architecture with business processes exposed as Web services
• Ensure COBOL code is highly tuned to offer optimum performance
• Store customer data in contemporary relational databases with sophisticated reporting and ad-hoc query capabilities available for business users
• Provide sophisticated Windows Graphical user interfaces and contemporary browser based web interfaces for customer and partner access over the internet
• Automate batch processes using contemporary job schedulers with built in self healing and paging facilities in the event of an issue occurring that would impact the business
• Offer mobile access from phones and PDAs     

It is true that historically many COBOL applications were unstructured monolithic systems with programs containing intermingled green-screen character user interface code, business logic and file access code.  If such applications have not been evolved to enable integration with other applications and technologies to meet today’s business needs then negative perceptions will arise. This is of course comparable to any application, written in any language, where the appropriate evolution has not taken place over an extended period of time.

Nevertheless existing applications will typically include business logic critical to the operation of the enterprise, consisting of a combination of core functionality and more advanced processes that can often represent the competitive differentiaion and distinctive competance of an enterprise or application package. Challenges with older applications typically relate not to the core functionality itself but how it is used, how it can be accessed and how it is presented. Rewriting an application can be a high risk endeavour over an extended period of time, consuming resources on replacing what isn’t broken – the core business processes. Modernization in contrast preserves this proven business logic while addressing the challenges of agility and presentation within some historical code.

Micro Focus offers an array of options to help you perform these extension tasks in an evolutionary, low risk manner by re-using as much of the existing application as possible. The key options to extend existing COBOL applications include:-

• Extending to a Service Oriented Architecture
• Integrating COBOL with .NET and J2EE
• Improving or Supplementing Existing User Interfaces
• Exploiting Relational Database Models     

Extending to a Service Oriented Architecture

Moving to a Service Oriented Architecture (SOA) is a strategic move for a COBOL application; in essence it unlocks the business logic in the COBOL application, rendering business processes, previously only accessible from within the program itself, as services that can be accessed by other IT systems across platforms and languages.

Through the use of a SOA, COBOL based systems can be:

• Reused from other IT systems within or outside an organization
• Extended to deliver new business functionality in hours and days, not months and years
• Accessed from an intranet or the internet while reusing existing business logic
• Repurposed to support significant business change such as system consolidation 
• Strategic as part of a contemporary heterogeneous IT architecture     

Web services provide a standards-based agile and portable route for delivering SOA. Micro Focus provides productive development tools and robust deployment capabilities to delivering COBOL as services into your SOA environment:  

• Our development tools enable COBOL developers to map, narrow and tailor an existing COBOL interface and to generate a Web service including infrastructure files, such as the WSDL file, tailored to your specific SOA implementation infrastucture
• Our deployment technology provides the capabilities for "direct" COBOL Web services i.e. Web services in COBOL can be deployed on Windows, UNIX, Linux and zLinux without requiring any third-party software or any .NET/J2EE application server
• Our deployment technology also enables integration with .NET and J2EE to provide an alternative means to deploy COBOL Web services by utilizing the .NET framework or the functionality of a Java Application Server such as IBM WebSphere, BEA WebLogic, Oracle or JBoss   

Integrating COBOL with .NET and J2EE

Through integration with .NET or J2EE, COBOL applications can be tightly coupled with other systems written for deployment on those environments, allowing COBOL to access the facilities and infrastructure of these environments and meet any requirement to deploy within them.

Micro Focus Net Express provides all the capabilities to tightly integrate COBOL within the .NET Framework.   COBOL applications can be developed and extended using Microsoft Visual Studio and deployed as managed or verifiable code within Micro Focus Server for .NET in conjunction with the Microsoft Common Language Runtime.  

Existing procedural COBOL code can be reused in .NET while COBOL applications can be extended to access .NET Framework Classes and Functions in the same way as any Microsoft language. With this support the capabilities of COBOL are significantly extended as your COBOL applications have access to a wide range of functions such as Web services, ADO.NET, Winforms and Webforms.  

Micro Focus COBOL Technology also provides J2EE compliant connectivity to COBOL applications through the Java Connector Architecture (JCA).   Developer tooling is provided that enables COBOL developers to map, narrow and tailor an existing COBOL interface and to generate an Enterprise Java Bean (EJB) for deployment with Micro Focus Server for SOA and a Java Application Server such as IBM WebSphere, BEA WebLogic, Oracle or JBoss.

Improving or Supplementing Existing User Interfaces

Green screen character user interfaces are very common and can still offer the most productive user interface for data processing operators entering large volumes of data. Such user interfaces therefore still have a role to play in today’s business environments but they are no longer appropriate for all the user communities of a contemporary business system.  

More intuitive graphical or browser-based user interfaces are required which are tailored to the specific needs of each user community.   Typically no one user interface style will be suitable for all different user communities and the key is to provide the most appropriate interface in terms of ease of use, aesthetics and available functions tailored to the needs of the different users.

In determining the correct approach to extending the user interface for any application, the key factors to consider include the existing architecture of the application, the architecture you are evolving to, platform dependencies, the type of interface required for the specific user community, the rollout and maintainability of the user interface, and the frequency of updates.  

Micro Focus offers a wide breadth of user interface extension capabilities to provide the flexibility our customers require.

• COBOL integration with the Microsoft Visual Studio Designer.   

• Composite applications using Microsoft languages for user interface     

• Composite applications using Java for user interface     

• Re-rendering user interfaces using thin client technology to improve user interface   

Exploiting Relational Database Models

Many COBOL applications utilize COBOL file formats as their data store as they offer the fastest way to store, retrieve and sort data. For many organizations the reports on this data are sufficient and there is no business imperative to change the data model of the application from COBOL file formats to a relational database model.  

Other COBOL applications utilize relational databases as their data store, often in conjunction with COBOL files, so high performance relational access is also vital to many COBOL applications. 

Micro Focus COBOL Technology therefore provides a database independent SQL access capability which works with any database that has an ODBC driver or ADO.NET data provider. OpenESQL enables access to all popular relational databases on Windows, UNIX, Linux and zLinux including Microsoft SQL Server, Oracle, IBM UDB, Sybase and Informix 

Often the need to provide better access to the data held in COBOL file formats arises, for example, the COBOL data needs to be accessed from applications written in other languages or from 3^rd party reporting tools. .  

Depending on the specific requirements there are a range of available options for modernizing Data access:

• ODBC/JDBC drivers are available for COBOL file formats which enable popular SQL access and reporting tools to be used with COBOL files. This mechanism helps present a relational view of the flat file data without compromising on the data access performance and requires no changes to the COBOL applications
• COBOL/XML support provides COBOL oriented syntax to create, consume and update XML documents and maps XML Data Schemas to and from COBOL copybooks, to provide a way to integrate COBOL and relational data
• RDBMS mapping technology is available for Micro Focus COBOL which enables the COBOL file access code to remain intact but the COBOL data is actually migrated to a relational database. This means the data is now held in a relation model so data access will not be as fast but it is more accessible
• Micro Focus and our partners can help move to a native RDBMS solution i.e. the COBOL data is migrated to a relational database and the COBOL file access code is replaced with SQL code. Again, data access is not as fast but the data is more accessible