One of the keys to successfully navigating this challenge is dependent on how well the IT Architect has gathered the Service Level Requirements. The Services Level Requirements will eventually translate in to a Service Level Agreement with the users and customers of the solution being implemented, deployed and operated.
The service description based on the ITIL approach would typically have the following items captured for a service in the requirements;
- Description of the service
- Who uses the service
- Components that make up the service Infrastructure/Applications
- Definition of how service is managed during interruption
- Times that the service is available
- Information on when service is unavailable (updates)
- Process for informing of outage
- Requirements for performance
- Capacity required including busy hours
- User or request response times
- Time to recover based on interruptions
- Level 1, 2 or 3 response times
- Business Continuity
These requirements are focused on the production environment they do not clearly state other requirements from a maintenance, change management and operations perspective.
The Quality Attributes are also constrained by the Financial elements of the Business Case.
The IT Architect is also constrained by the resources made available to them including Budget, Time to Market, privacy and new technologies. If the customer requires a highly available solution defined by regulatory requirement but does not have a budget available for Disaster Recovery, how is the solution going to be delivered?