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A guide to network lifecycle management
Network pros should use a network lifecycle management process to monitor, manage and implement changes in their network, regardless of if they use PPIDOO or another framework.
Without a lifecycle management framework, it's difficult for network teams to predict how changes will affect UX and the system itself. The network lifecycle management process provides structure to these changes for a more effective network.
Using the network lifecycle management process, network pros can plan and implement changes and guide ongoing network operations. By following the phases of a network lifecycle, teams can learn network behavior, reconfigure their networks to adapt to changes and improve their overall business strategy.
Network lifecycle phases and frameworks
The simplest form of network lifecycle management consists of three phases:
- Plan.
- Build.
- Manage.
These phases are also known as design, implement and operate. The cycle always repeats as the plan phase identifies new requirements. Network teams can also apply the lifecycle process to subtasks.
Network lifecycle management phases are often adapted into different frameworks, including the following.
ITIL framework
Information Technology Infrastructure Library (ITIL) is a management framework that describes a similar process. The ITIL framework has five phases as opposed to the three previously described. It focuses on service strategy, service design, service transition, service operations and continual service improvement.
Network teams should integrate the fifth phase -- continual service improvement -- simultaneously with the first four phases so teams can improve operations as necessary.
PPDIOO framework
It can be beneficial to expand the basic three-phase network lifecycle into subphases. Cisco developed a six-phase network management lifecycle: prepare, plan, design, implement, operate and optimize (PPDIOO).
The extended PPDIOO model breaks the three-phase lifecycle into the following subphases:
- The plan phase expands into the prepare, plan and design phases.
- The build phase is developed into the implement phase. This sometimes includes the procure phase, which Cisco omits from its model.
- The manage phase incorporates the operate and optimize phases.
Examine the PPDIOO network lifecycle
Below is a look at the steps included in each of the six PPDIOO lifecycle phases defined by Cisco.
1. Prepare
The most critical step in any business process is to identify business requirements and outline business goals. During this stage, teams spend most of their time determining where their business needs to be at the end of the cycle so they can assess how the network can best support those goals. In this phase, network pros should perform financial analyses and calculate the ROIs for potential changes.
Teams should also anticipate future needs. Consider tracking industry trends and understand how they can be important to the business. Other sources of information include industry analysts and conferences.
2. Plan
The plan phase closely follows the prepare phase. Here, teams begin creating project plans to help their organizations manage the remainder of the lifecycle. Consider questions related to vendor selection and management, such as the following:
- How will teams fund the necessary equipment and supplies?
- Which vendors should teams consider?
- Is that hot new startup with the latest technology worth the risk?
3. Design
The design phase gets into the details -- subject to the limitations identified in the prior phases -- such as budget. The design team creates a detailed network design that meets the requirements using the selected vendors. Thorough documentation is vital in this phase.
It might be necessary to build prototypes and conduct proofs of concept. This minimizes the risk of using any new technology. This phase is also the point at which new processes might need to be defined, such as when to adopt automation.
4. Implement
In this stage, the implementation team transitions from the previous cycle into the new deployment. Organizations have adopted the philosophy that the design group implements the changes. Once the design has been fully validated and automated and can be managed, they hand it over to the operations team.
5. Operate
The operation phase begins when the new network -- or new parts of the network -- is functional and has a defined operational process. This phase is where network management design is thoroughly tested. However, teams should have already identified common operational problems during the design and implementation phases. As such, they should have created mechanisms for monitoring and diagnosing those problems.
6. Optimize
The final lifecycle phase continues refining the design and operations of the new network functions. This is when network pros create processes for identifying unforeseen operational problems and ways to improve the network, including the processes used to operate it.
Beware of overoptimizing certain aspects of the network. This can cause other operational problems. For example, while trying to save money on capital equipment, teams might modify a branch design that results in multiple variations. Ultimately, this might result in greater Opex.
What about testing?
Testing isn't listed as a step because teams should incorporate it in each phase. Testing is a key element of the design, implement, operate and optimize phases. The preparation phase also uses testing. Network pros might test the business leaders regarding the risk of using new technology.
Incorporating the network lifecycle with business processes
Top-performing organizations incorporate some form of network lifecycle management process in their overall IT strategy, including the annual IT planning and budgeting process. It's possible that many network pros have been using a similar ad hoc process without knowing the formal definitions.
Many enterprises follow a three-year network lifecycle. In this timeline, enterprises upgrade approximately one-third of the network infrastructure every year. This ensures companies use modern technology. Using this model, enterprises can follow industry trends and technology innovations while predicting their year-to-year budget and staffing requirements. Other organizations might need to adjust their cycle durations to fit their needs.
Regardless of the cycle duration, it makes sense to formally adopt and incorporate a network lifecycle process into annual business planning processes.
Editor's note: This article was originally written by Terry Slattery and updated by TechTarget editors to improve readability.
Terry Slattery is an independent consultant who specializes in network management and network automation. He founded Netcordia and invented NetMRI, a network analysis appliance that provides visibility into the issues and complexity of modern router- and switch-based IP networks.
