Companies that have traded for a number of years will probably have one or more legacy bespoke business software systems that have a ‘maintain or replace’ question mark hanging over them. Given the high rate of change in contemporary enterprise IT architectures, answering this question is not getting any easier. There are a number of well known factors at play when considering whether to maintain or replace an application. The most common of these are detailed in table 1 below.

Table 1 : Application Metrics, Ranks and Remedies

If you answer No to any of the rank 1 questions or answer Yes to a majority of the rank 2 questions your application is probably a candidate for some form of modernisation.  Modernisation can take a number of forms including performance optimisation, re-platforming, re-hosting and recoding. The form of modernisation suitable in your instance will depend on the combination of metrics that affect you application. Remedies for poor metric scores are proposed above.

In the instance where applications score poorly in relation to Functional Fit and Mulit-Device Availability it is probable that some form of recoding will be required. The options here will include application translation (i.e. using software tools to automate the porting of the application for one platform to another) or application recoding.  Careful consideration needs to be given to the supportability of ported applications due to bloating of the code base if considering automated porting over application recoding.

Recoding and rehosting of legacy applications provide a significant opportunity to reduce application support cost from a number perspectives: internal infrastructure costs are replaced with incremental subscription costs when migrating to the cloud. The high costs of maintaining legacy technologies and scarce resources are replaced with the lower costs associated with using current technologies (possibly open source) and technical skills that are more widely available.

Historically, it has been common that application modernisation projects have been undertaken from the perspective of minimising costs and risks. Application modernisation projects also afford the opportunity to deliver significant competitive advantage for the organisation. Given the investment involved, it is important that due consideration is given to maximising this advantage for all project stakeholders.