A guide to network lifecycle management
Network pros should follow a network lifecycle to monitor, manage and implement changes in their networks, regardless of whether it's a plan, build and manage framework or PPDIOO.
The network lifecycle management process helps network pros plan for changes, implement those changes and guide ongoing operations. What is this process, and how can network teams apply it?
Without some sort of framework, it is difficult for network teams to predict how changes will affect UX and the system itself. Teams can learn network behavior, reconfigure their networks to adapt to changes and improve their overall business strategy by following the phases of a network lifecycle.
Network lifecycle phases
In its simplest form, network lifecycle management consists of three phases: plan, build and manage. It is also known as design, implement and operate (DIO). The cycle is repeated as the plan phase identifies new requirements. The lifecycle process can also be applied to subtasks.
The Information Technology Infrastructure Library (ITIL) is another management framework that describes a similar process. It focuses on service strategy, service design, service transition and service operations. The fifth phase, continual service improvement, should be integrated simultaneously with the first four phases, so teams can improve operations as necessary.
It can be beneficial to expand the basic three-phase network lifecycle into subphases. For example, 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 can sometimes include the procure phase, which Cisco omits).
- The manage phase incorporates the operate and optimize phases.
Examining the PPDIOO network lifecycle
Below is a look at what steps are included in each of the six phases of the PPDIOO lifecycle defined by Cisco.
Like any business process, the most critical step is identifying the requirements and outlining 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. At this point, network pros should perform financial analyses and calculate the ROIs for potential changes.
Teams should also learn how to anticipate future needs. For example, they should consider tracking industry trends and understand how they can be important to the business. Other sources of information include industry analysts and conferences.
The plan phase closely follows the prepare phase. This is when teams begin to create project plans to help their organizations manage the remainder of the lifecycle. Teams should consider questions related to vendor selection and management, such as the following:
- How will the necessary equipment and supplies be funded?
- Which vendors should be considered?
- Is that hot new startup with the latest technology worth the risk?
The design phase starts to get into the details, subject to the limitations identified in the prior phases, such as budget. The design team should create a detailed design that meets the requirements using the selected vendors.
This is when it may be necessary to build prototypes and conduct proofs of concept to minimize the risk of using any new technology. This is also the point at which new processes may need to be defined, such as when to adopt automation.
In this stage, the implementation team transitions from the previous cycle into the new deployment. Organizations have started to adopt the philosophy that the design group does the implementation and only turns it over to the operations team once the design has been fully validated, automated and can be managed.
Operations takes over when the new network -- or new parts of the network -- is functional and operational processes are defined. The design and implementation phases should have identified common operational problems and created mechanisms for monitoring and diagnosing those problems. This phase is where network management design is thoroughly tested.
The final phase of the lifecycle continues to refine the design and operations of the new network functions. This is when network pros create processes for identifying unforeseen operational problems and identify ways to improve the network, as well as the processes used to operate it.
Network teams should beware of overoptimizing aspects of the network that cause other operational problems. For example, modifying a branch design that results in multiple variations simply to save some money on capital equipment may result in greater Opex.
What about testing?
Testing isn't explicitly listed as a step because it should be incorporated in each phase. Testing will be a key element of the design, implement, operate and optimize phases. There is also testing in the preparation phase, where network pros may test the business leaders regarding the risk of using new technology.
Incorporating the network lifecycle with business processes
Top-performing organizations will incorporate some form of network lifecycle management process as part of their overall IT management process. It's possible that many network pros have been using a similar ad hoc process without knowing the formal definitions. Top organizations incorporate the network lifecycle into the annual IT planning and budgeting process.
Some enterprises follow a three-year network lifecycle. In this timeline, approximately one-third of the network infrastructure is upgraded every year to ensure the companies are using modern technology. They can follow industry trends and technology innovations while predicting their year-to-year budget and staffing requirements. Other organizations may need to increase or decrease their cycle durations to fit their needs.
Regardless of the cycle duration, it makes sense to formally adopt a network lifecycle process and incorporate it into the annual business planning process.