Modern IT systems have to meet tough demands: they are accessed via the web sometimes from all over the world, they must be highly available (often 24x7x365), they have to integrate with a multitude of systems (both internally and those of suppliers and partners), and they have to be flexible enough to cope with rapidly changing business processes.

Therefore today's IT archtectures are, by necessity, complex. However in many cases there are many ways to achieve the same result so the trick here is to choose the most appropriate achitecture and products to meet the requirements, whilst keeping it as simple and as adaptable as possible.

Technical architecture should consider:

• scalability and capacity planning
• security and user provisioning, both internal and external
• availability requirements and failure modes
• disaster recovery approach and failover time
• data centre power consumption
• application integration points
• database availability
• operational management

With such a long shopping list of requirements it is easy to over-engineer a solution. What is important here is to consider the real service level needs, which may or may not be already enshrined in a Service Level Agreement (SLA) with the business.

Note that sometimes an SLA will be overly demanding; for example, it is tempting for the business to specify that a website must be available 24x7, whereas in practice by looking at customer usage patterns, it may be possible to scale back this to accommodate early hours outages. Alternative there may be a half-way house such that at times the website content may be active whilst the transactional side, such as a booking engine, may be unavailable for system maintenance or upgrades. The point here is that the most cost effective solution overall may not necessarily be the most sophisticated one.

On the other hand, a reliable and fault tolerant infrastructure, whilst more complicated to set up, can provide less tangible benefits such as not requiring your support staff to diagnose and fix systems in the middle of the night (and thus reducing support costs and risk of error).

Veriton has designed approriate IT architectures, based on Oracle products, for a range of mid-sized organisations. These meet the needs for web-delivered applications for call centres and demanding web sites, along with web service based integration with partners.