How Archiving Can Free You from Legacy Application Headaches

Archiving isn't just for old data. We explain the process and benefits of archiving applications no longer used.

Archiving is starting to be used by some mainframe shops as a cost-effective alternative to keeping legacy applications running once they are no longer being actively updated. It is a simple way of removing key data from the applications and keeping it accessible online – to meet customer service or other operational needs, as well as for compliance.

With the data removed, the legacy application itself can be switched off, freeing staff from supporting obsolete applications and reducing risk and costs for the organization.

Archiving is often used as a way of decommissioning core legacy mainframe applications that have accumulated large volumes of valuable data over many years. This enables IT resources to be released and used more productively.

Despite the benefits, this type of archiving is not yet widely undertaken or understood. In this article we'll take a closer look at the process.

Application Archives

Mainframe user organizations often feel forced to keep aging applications running way beyond their use-by date -- because they contain critical historical data that must stay accessible. Yet keeping obsolete systems alive -- just to view the data -- puts a real strain on resources.

Supporting legacy applications can be expensive, especially as older systems may require specialist skills to keep them ticking over. By moving the underlying data to a secure, searchable archive and decommissioning the original application, you reduce the reliance on expensive legacy IT skills. You no longer have to pay support and maintenance charges and can divert IT staff to more strategic initiatives such as developing new systems.

Archiving can also increase productivity and service levels by providing fast, easy access to data while eliminating the need for new users to learn how to extract information from old, unfamiliar systems.

Compliance obligations are fulfilled because data can be archived in a read-only, tamper-proof format and archive rules can be created to automatically delete data at the end of its life.

What to Archive

Archiving usually relates to historical data that is no longer being updated. This can include information such as billing records, financial transactions, and customer or work history information. Data located in database tables, documents, diagrams, and images can all be successfully archived. The benefits generally increase where legacy applications are eating up budgets maintaining large data volumes going back several years.

A popular approach to archiving is to present the data within the archive in replicas of the original application screens, which keeps the data in context and in a familiar layout. Any ambiguous codes or terminology that are not self-explanatory can be translated into more meaningful information. For example, "payment code 01" may be presented as "monthly billing." The intention is to ensure that no application-specific knowledge will be needed to search or interpret the data once it is archived. This will be important for future users who will be unfamiliar with the original application

Specialist tools are used to re-assemble the data to create virtual screen views of the archived information. Many organizations want the data to be presented in a similar layout to the original application. Others choose to have a new arrangement that more closely ties in with how end users will want to access the data and work with it in the future. Either way, authorized users are easily able to find the information they need. This includes being given the ability to "mine" data using standard search facilities, as well being able to reprint and e-mail the data or export it to third-party applications when required. In this way, the legacy data becomes far more usable.

Why not just stash the legacy data away onto tape or move it to a new application? Simply writing legacy data in a raw format to tape, or other offline storage, does not provide a satisfactory solution. Separated from the original application, the raw data will be out of context, slow to access, and impractical and inefficient to trawl through.

Migrating large volumes of historical data to another application could significantly impair system performance. Extra disk space and back up storage would also be needed, at additional cost.

Rewriting legacy applications using new technology, just to support read-only access to data, is time-consuming and costly.

The Archiving Process

Archiving is a quicker and simpler approach, compared with the options we've already mentioned. An archiving specialist should take you through a structured process that involves working closely with the relevant business departments and end users to ensure you meet your business and technical objectives. Typical steps will normally include:

  • Business Analysis: Understanding why the business needs to retain the legacy data and how it will be used in the future
  • Systems Analysis: Defining the scope of the task, identifying where the data is located and its format
  • Data Extraction: Making a detailed assessment of how the data is to be extracted; taking account of whether it is contained in databases tables, document images, print spool files, or a combination of these sources
  • Process the Data: Ensuring the data can be easily understood by end users; includes performing real-time calculations and translating application-specific codes or terminology into meaningful on screen information
  • Create Screen Views: Creating screen views that will allow end users to view and navigate through the data
  • User Acceptance Testing: Creating a prototype using sample data that is tested with business users
  • Archive the Data: Following successful acceptance testing, the archive is populated with the legacy data
  • Switch Off the Application: The original application can now be decommissioned

It is common for organizations to create a central archive which holds data from a variety of legacy applications, not just a single application. This is one of the key advantages of archiving. End users know they have a single repository for all legacy data and are familiar with how to use it. The IT department can optimize resources by having an existing resource into which they can transfer legacy data as applications reach end of life. They have a single system that can archive data from potentially many different legacy applications.

What's more, IT can keep archived data within the mainframe environment. It is possible to archive legacy mainframe data onto a separate server or to create an archive that remains within the high-performance mainframe environment. One emerging approach is to host the archive using the lower-cost specialty z/Linux processor.

Real-World Benefits

Legacy archiving is versatile and has been used by in a variety of industry sectors. Examples include a gas distribution company that created a central archive to house several terabytes of pipeline work history data from multiple legacy applications A power company decommissioned several legacy billing applications it had inherited through mergers and acquisitions to create a central archive consisting of billions of records, including customer data such as meter readings and customer service notes. In the financial services sector, many organizations have used a similar approach to maintain access to large volumes of historical transaction data for compliance purposes.

If legacy applications are causing you headaches, it's time to explore the benefits of archiving applications in your own environment.

Lynda Kershaw is marketing manager at archiving and application decommissioning expert Macro 4, a global software company that helps organizations improve the performance of critical business applications. Macro 4’s Document Management solutions capture, store, present and deliver business-critical data and documents electronically and physically and increase the efficiency of key processes such as SAP ERP and application decommissioning as well as supporting call centre and online customer service. You can contact the author at

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