Factors Affecting Deployment Design

Several factors influence the decisions you make during deployment design. Consider the following key factors:

• Logical Architecture. The logical architecture details the functional services in a proposed solution and the interrelationships of the components providing those services. Use the logical architecture as a key to determining the best way to distribute services. A deployment scenario contains the logical architecture paired with quality of service requirements (described below).

• Quality of service requirements. The quality of service (QoS) requirements specify various aspects of a solution’s operation. Use the QoS requirements to help develop strategies to achieve performance, availability, scalability, serviceability, and other quality of service goals. A deployment scenario contains the logical architecture (described previously) paired with quality of service requirements.

• Usage analysis. Usage analysis, developed during the technical requirements phase of the solution life cycle, provides information on usage patterns that can help estimate load and stress on a deployed system. Use the usage analysis to help isolate performance bottlenecks and develop strategies to satisfy QoS requirements.

• Use cases. Use cases, developed during the technical requirements phase of the solution life cycle, lists distinct user interactions identified for a deployment, often identifying the most common use cases. Although the use cases are embodied in the usage analysis, when assessing a deployment design you should refer to the use cases to make sure that they are properly addressed.

• Service level agreements. A service level agreement (SLA) specifies minimum performance requirements, and when those requirements are not met, the level and extent of customer support that must be provided. A deployment design should easily meet the performance requirements specified in a service level agreement.

• Total cost of ownership. During deployment design you analyze potential solutions that address the QoS requirements for availability, performance, scalability, and others. However, for each solution you consider, you must also consider the cost of that solution and how that cost impacts the total cost of ownership. Make sure that you consider the trade-offs embodied by your decisions and that you have optimized your resources to achieve business requirements within business constraints.

• Business goals. Business goals are stated during the business analysis phase of the solution life cycle and include the business requirements and business constraints to meet those goals. Deployment design is ultimately judged by its ability to satisfy the business goals.