N10-007 Explain the basics of change management procedures

Organizations in all industries-particularly financial services, retail, and communications-are increasingly dependent upon IT and a highly available network to meet their business objectives. In particular, the advent of online business transactions has made the network a critical business component that is expected to function properly with little or no downtime. As customer expectations and demands rise, network operations teams are focusing on IT service-quality improvement and achieving higher levels of availability by re-examining processes and procedures-particularly in the area of change management-because changes to the network are often a source of downtime.

Scope

The Change Management Process is the mechanism used to initiate, record, assess, approve and resolve project changes. Project changes are needed when it is deemed necessary to change the scope, time or cost of one or more previously approved project deliverables. Most changes will affect the budget and/or schedule of the project.

Policy

The use of the formal change management procedure will be required when any changes are discovered or requested which impact previously reviewed, approved and published project deliverables.

The documentation and tracking of all change requests will be managed using the defined procedure and facilitated by the use of the change management log.

A multi-tiered approach will be used to approve change requests:

• The Project Manager will make decisions to analyze and decisions to proceed with changes if the changes do not impact scope, budget or schedule or result in an increase in risk for the project.
• Changes which do impact scope, budget or schedule will be forwarded to the Steering Committee for review. The Steering Committee will advise the Project Sponsor.
• Where the [functional owner] has the resources to absorb the impact of the change, the Project Sponsor will make the final decision, based upon the information provided by the Project Manager and the input of the Steering Committee. The Project Sponsor, the [advisor], and [advisor] will discuss requests that may result in a significant change in scope, schedule, and budget, i.e. the impact of the change cannot be covered by [functional owner] resources. This group will advise the Steering Committee.
• The Steering Committee will make the final decision based upon the information provided

Decision Matrix

The following is a general guideline for the change management process. Most
changes will require a subset of the steps listed.

Procedures

Each request will be tracked from the time of presentation through:
1. Identify (identify and document the required change)
2. Validate (verify the change is valid and requires management)
3. Analyze (analyze and record schedule, cost and effort impact of change)
4. Control (decide whether to execute the change)
5. Action (execute decision, including revision to project plans if necessary)
6. Close (verify that action is complete and close change request)

Identify Change Request

Validate Change Request

Analyze Impact

Control Change Request

Action Change Request

Close Change Request

Documentation

Configuration management is a collection of processes and tools that promote network consistency, track network change, and provide up to date network documentation and visibility. By building and maintaining configuration management best-practices, you can expect several benefits such as improved network availability and lower costs. These include:

• Lower support costs due to a decrease in reactive support issues.
• Lower network costs due to device, circuit, and user tracking tools and processes that identify unused network components.
• Improved network availability due to a decrease in reactive support costs and improved time to resolve problems.

We have seen the following issues resulting from a lack of configuration management:

• Inability to determine user impact from network changes
• Increased reactive support issues and lower availability
• Increased time to resolve problems
• Higher network costs due to unused network components

Current Device, Link, and End-User Inventory

Current device, link, and end-user inventory information enables you to track network inventory and resources, problem impact, and network change impact. The ability to track network inventory and resources in relation to user requirements helps ensure that managed network devices are actively used, provides information needed for
audits, and helps to manage device resources. End-user relationship data provides information to define change risk and impact, as well as the ability to more quickly troubleshoot and resolve problems. Device, link, and end-user inventory databases are typically developed by many leading service provider organizations. The leading developer of network inventory software is Visionael Corporation leavingcisco.com . The database may contain tables for like devices, links, and customer user/server data so that when a device is down or network changes occur, you can easily understand the end-user impact.

Configuration Version Control System

A configuration version control system maintains the current running configurations of all devices and a set number of previous running versions. This information can be used for troubleshooting and configuration or change audits. When troubleshooting, you can compare the current running configuration to previous working versions to help understand if configuration is linked to the problem in any way. We recommend maintaining three to five previous working versions of the configuration.

TACACS Configuration Log

To identify who made configuration changes and when, you can use TACACS logging and NTP. When these services are enabled on Cisco network devices, the userid and timestamp is added to the configuration file at the time the configuration change is made. This stamp is then copied with the configuration file to the configuration version control system. TACACS can then act as a deterrent for unmanaged change and provide a mechanism to properly audit changes that occur. TACACS is enabled using the Cisco Secure product. When the user logs into the device, he/she must authenticate with the TACACS server by supplying a userid and password. NTP is easily enabled on a network device by pointing the device to an NTP master clock.

Network Topology Documentation

Topology documentation aids in the understanding and support of the network. You can use it to validate design guidelines and to better understand the network for future design, change, or troubleshooting. Topology documentation should include both logical and physical documentation, including connectivity, addressing, media types, devices, rack layouts, card assignments, cable routing, cable identification, termination points, power information, and circuit identification information.
Maintaining topology documentation is the key to successful configuration management. To create an environment where topology documentation maintenance can occur, the importance of the documentation must be stressed and the information must be available for updates. We strongly recommend updating topology documentation whenever network change occurs.