PPDIOO Six Phase Life Cycle Explained: Cisco has formalized a network’s life cycle into six phases: Prepare, Plan, Design, Implement, Operate, and Optimize. These phases are collectively known as PPDIOO.
Prepare Phase
The Prepare phase of PPDIOO establishes organization and business requirements, develops a network strategy, and proposes a high-level conceptual architecture to support the strategy.
Technologies that support the architecture are identified. This phase creates a business case to establish a financial justification for a network strategy.
Plan Phase
The Plan phase identifies the network requirements based on goals, facilities, and user needs.
This phase characterizes sites and assesses the network, performs a gap analysis against best-practice architectures, and looks at the operational environment.
A project plan is developed to manage the tasks, responsible parties, milestones, and resources to do the design and implementation.
The project plan aligns with the scope, cost, and resource parameters established with the original business requirements. This project plan is followed (and updated) during all phases of the cycle.
Design Phase
The network design is developed based on the technical and business requirements obtained from the previous phases.
The network design specification is a comprehensive detailed design that meets current business and technical requirements.
It provides high availability, reliability, security, scalability, and performance. The design includes network diagrams and an equipment list.
The project plan is updated with more granular information for implementation. After the Design phase is approved, the Implement phase begins.
Implement Phase
New equipment is installed and configured, according to design specifications, in the Implement phase. New devices replace or augment the existing infrastructure.
The project plan is followed during this phase. Planned network changes should be communicated in change control meetings, with necessary approvals to proceed.
Each step in the implementation should includes a description, detailed implementation guidelines, estimated time to implement, rollback steps in case of a failure, and any additional reference information.
As changes are implemented they are also tested before moving to the Operate phase.
Operate Phase
The Operate phase maintains the network’s day-to-day operational health. Operations include managing and monitoring network components, routing maintenance, managing upgrades, managing performance, and identifying and correcting network faults.
This phase is the design’s final test. During operation, network management stations should monitor the network’s general health and generate traps when certain thresholds are reached.
Fault detection, correction, and performance monitoring events provide initial data for the optimize phase.
Optimize Phase
The Optimize phase of PPDIOO involves proactive network management by identifying and resolving issues before they affect the network.
The Optimize phase may create a modified network design if too many network problems arise, to improve performance issues, or to resolve application issues. The requirement for a modified network design leads to the network life cycle beginning.
