The Legacy Challenge
Legacy IT systems are business services that were implemented many years ago using a combination of software and hardware that the original manufacturer no longer supplies or supports. Legacy systems are in widespread use in commercial and public sector organisations for three principal reasons:
- The system continues to meet the basic business requirement - the business users are often satisfied that they don't need new features or functions and have no business-led plans to upgrade or replace the system.
- Legacy systems are typically supported by a number of IT departments, all of whom share the operational risks but none of whom "own" the entire legacy problem.
- When based on a traditional approach, the business case for upgrading such systems is not persuasive and is rarely successful - due to a combination of minimal business appetite for change, the fragmented IT ownership issue and the prohibitive costs.
Supportability Issues
As hardware and software reach the end of their support lifecycle, IT organisations face a multitude of challenges in providing support for the associated business systems.
- Hardware Support - the manufacturers of the hardware may declare the equipment to be "end of life" at which point the availability and quality of support for the hardware starts to diminish or be withdrawn entirely. Maintenance contracts in this scenario can become prohibitively expensive, even if a supplier is prepared to continue to provide this service. Simple things like the ability to procure spare parts in the event of a hardware failure can give support staff major headaches.
- Software Support - the manufactures of the software adopt the same approach to "end of life" software. The vendor may no longer be releasing software patches, leaving the product and business service vulnerable to failure and potentially to security exposures.
- Knowledge & Skills - the number of people with current knowledge of the hardware and software components that make up legacy systems will inevitably diminish over time. This applies to both staff associated with the product manufacturers and internal company support staff.