Measuring the Benefits
Understanding exactly what is "adaptive" about adaptive infrastructure can be a complex task. Figure 1.8 shows the various measurements used to quantify the agility and range of your adaptive infrastructure.
Figure 1.8 Measuring Adaptive Range
Scalability.
Scalability means building in some headroom so that your infrastructure doesn't have to be changed repeatedly as the user base for an application increases. Scalability is a relatively easy but potentially expensive way to be adaptive. Later sections of this book will highlight best practices that can be used to achieve scalability without spending too much up front, primarily by assuring that incremental scalability is a feature of the architecture and technology choices.
Presentation independence.
Another dimension that affects virtual-ly every organization is presentation: the way information is presented to users or business partners. Historically, the presentation layer has shown little adaptability. Organizations now spend much time and effort converting more traditional 2-Tier, "smart PC" applications into Web-based applications.
Unfortunately, designing Web-only presentation solutions is equally limiting. Other presentation methods, such as wireless devices (mobile phones or PDAs) and interactive voice response units (IVRs), can't support a full-page Web display and will require expensive and time-consuming development efforts. If consistency across multiple points of interaction is important to your brand, your designers should make sure it can be achieved without significant infrastructure replacement efforts and without rewriting code.
Presentation independence alone, however, doesn't guarantee sufficient adaptability. Infrastructure planners should be very focused on the front end, but if the application-to-application integration issues aren't addressed simultaneously, the result is taller stovepipes with applications that don't fit the adaptive infrastructure concept.
Partitioning.
The ability to partition functionality and complexity within the infrastructure is another benefit of adaptability. If the infrastructure cannot be partitioned effectively, the resulting complexity spreads throughout the organization and eventually becomes unmanageable. For success, you must manage the interfaces between applications and between infrastructure components effectively, both for applications used within the enterprise and for those used by external partners.
Integration/reuse.
Infrastructure integration and reuse are also measures of adaptability. The typical organization requires a dramatic increase in the reuse of infrastructure code, other technology components, and skills to increase adaptability and speed of deployment. Reusable code is the opposite of legacy code. Whereas most legacy code is difficult to maintain, enhance, and integrate, the most adaptive code has clean, well-documented interfaces. These interfaces enable bits of code to be changed or added without requiring major changes in other code.
Increasingly, you must describe the value proposition for infrastructure directly to the business users in terms of the discrete service levels that they want delivered. By turning to a discussion of service levels, you can influence business users to consider more than just the immediate impact of a single application. You must convince the business to consider the value of adaptability, because it will take more money, effort, and time to deliver than single implementations.