IT Operating Environments Best Practices

Overview

The isolated-vs-shared decision is one of the most consequential environment architecture decisions a team makes, and one of the most frequently made without deliberate consideration. Teams default to shared environments because they inherit shared infrastructure from the organization’s existing environment landscape. Teams default to isolated environments because they have the organizational resources to provision dedicated infrastructure and prefer to avoid coordination overhead. In neither case is the decision typically framed as a governance decision with documented implications. The result is an environment landscape whose isolated-vs-shared profile is not understood in aggregate, whose coordination obligations are not managed consistently, and whose cost and risk profile cannot be analyzed because the fundamental architectural model of each environment is not recorded.

Figure: Isolated vs. Shared Environment Decision Tree — This figure shows a decision path for choosing isolated or shared Environment Instances based on risk, sensitivity, sharing compatibility, cost constraints, agility needs, solution scale, and governance capability.

Best Practice

Require that the isolated-vs-shared decision be made explicitly, documented in the environment’s inventory record, and reviewed by the environment governance process as part of environment creation approval. For teams requesting a new Environment Instance, the governance process should surface the isolated-vs-shared question explicitly and require the requesting team to declare their intended model and confirm that they understand the governance implications. For isolated environments, confirm that the team has a plan for the environment’s full lifecycle including eventual decommissioning. For shared environments, confirm that a coordination model exists, that all teams sharing the environment are aware of the shared model and have agreed to the coordination requirements, and that data governance obligations for the multi-application data landscape of the shared environment have been identified and assigned.

Benefit(s)

Making the isolated-vs-shared decision a required, documented part of the environment creation process ensures that the governance implications of each model are addressed before the environment is deployed rather than discovered after problems have materialized. Shared environment coordination failures - deployment conflicts, data contamination, configuration collisions - are prevented or mitigated by coordination mechanisms established at environment creation time. The organization’s environment landscape becomes visible and analyzable in aggregate because the fundamental architectural model of every environment is a known, recorded attribute rather than an implicit assumption.