There is no question that mobile purchasing is on the increase, with the number of smartphones in use globally expected to hit 1.7 billion by 2013 (Analysys Mason, July 2010). Visits to e-commerce sites from mobile devices, often to research products and compare prices are becoming a significant part of the shopping experience with 15% of mobile phone owners doing so on a monthly basis at present (Experian Simmons).

As technology evolves, and new trends emerge, end users’ demands and expectations of software applications are constantly changing. The emergence of social media and Web 2.0 applications like Facebook and new mobile platforms, such as iOS and Android, are driving users to expect a similar experience and accessibility from their business applications.

However, all too frequently businesses are finding that their mobile apps are incompatible with the existing business IT infrastructure.

One main challenge is the supporting of new operating environments. Businesses need to consider the different mobile web versions for iPhone, Blackberry, Windows and Android smartphones. In addition to this, businesses must ensure that any business applications adapted for mobile use have been thoroughly tested to reduce the risk of project failure and help lower ongoing maintenance costs.

Another challenge for the application builder is viewing the provision of mobile services and content as a case of “how” rather than “what”. Many core applications will already be comprised of well-defined discrete functions that individually or collectively provide a business service and proven value. So, the mechanics of exposing these services and integration with existing systems is often the main challenge and a good test of architectural prowess.

The trick is to re-use as much of what is already working as possible, and only build new what is absolutely needed (in this case the presentation logic for the mobile device(s). Rewriting the back-end system for the sake of a new user interface is overcomplicating an already complex IT task; both Gartner and Standish have warned of the dangers of writing anew core business systems, or replacing them with generic packages.

Importantly, much of the good work done providing web portals can be harnessed for mobile computing – if applications are already connected with web channels, IT can focus on the content delivery and management of existing functionality to mobile devices. What has to be delivered for the first time is then simply the mobile interface. The rest of the plumbing is theoretically already working.

For thick client or 2-tier applications, separating tightly coupled business and user logic can scupper good intentions for reuse in mobile and web systems – this is telling IT that the original design was not future-proofed, and can be a good reason for application architecture review.

Ironically perhaps, older core systems such as those using COBOL are better architected for re-use in a mobile world, as the core logic is more easily accessible from remote devices. As a result many businesses are choosing to build web service application portals as the simplest approach to accessing existing business logic.

In order to future proof systems for the rise of mobile, businesses should assess existing infrastructure; and not fall into the trap of re-writing systems. The key to this is to re-use as much already working as possible and look at how this can be built upon where needed.