Itil I understand-my experiences in Guide

I. ITIL Overview
Speaking of ITSM, we have to start with enterprise informatization.
In the process of enterprise informatization, a large number of related hardware and software facilities are required. We call this an IT infrastructure.
With the rapid informatization of enterprises, the IT infrastructure is becoming increasingly large and increasingly difficult to manage and maintain. In a slightly larger company, especially an information technology company, you will see the technical staff "Saving fire" everywhere ".
Faced with this embarrassing reality, the British CCTA (now the British commerce department OGC. This is probably the case, because when I read a book, I thought it was like CCTV, So I remembered it.) I developed the ITIL prototype.

Previously, it was said that ITSM is an industry and a field. ITIL is one of the standards in this industry (there is also a bs1500 developed based on ITIL, with security-centered BS7799, audit-oriented COBIT ).

Ii. ITIL process details
ITIL was originally composed of about 40 books, each of which describes a process, that is to say, there are almost 40 processes (exaggerated by foreigners ).
The Guide only describes ten core processes and one management function of itil. They are:
A management function: the service desk.
Ten core processes:
Service Support: configuration, change, release, accident, Problem
Service provision: service level, continuity, finance, capability, and availability.

Service Desk ):
A "front-end" (a centralized and dedicated service contact point), which can handle a large number of customer requests without contacting specific technical personnel.

Configuration Management:
This process provides the configuration of the IT infrastructure.
defined in the document: a service management process consists of identifying and verifying system configuration items, recording and reporting configuration item statuses and change requests, and verifying the correctness and integrity of configuration items.
1. configuration items (CIS) are the most basic information units in configuration management ). Software, hardware, and various documents are CI.
2. All CI instances are in the configuration management database (CMDB ). Note: the relationship between Ci and CI exists in CMDB.
3. Differences from asset management: Asset Management only records the purchase time, price, depreciation information, and position of assets.

change management:
enterprise business changes lead to changes in the IT infrastructure, and naturally it services have to be changed.
the definition in the book: refers to the service management process that controls the infrastructure or any change to a service within the shortest time of interruption. When the problem management finds the root cause of the problem through investigation and analysis, but cannot formulate an appropriate solution to fundamentally solve the problem, the problem management must submit a change request to the change management, so as to fundamentally eliminate the root cause of the problem by implementing necessary changes.
1. A Change Advisory Board (CAB) is required ).
cab is composed of change manager, customer, User Manager, user group representative, application developers, maintenance personnel, relevant experts and technical consultants.
2. Responsibilities of cab:
A. reviews the change requests submitted in the problem management process and determines whether to approve the change requests.
B. provide comments to the Change Manager to assess the potential impact of a change and determine the priority of the change.
release management:
release the tested software and hardware version to the target change point and ensure the corresponding service level.
release management plans and implements changes to IT services and describes all aspects of changes.
1. types: Delta release (incremental release), full release, and package release, the Guide explains that package release refers to the release of a set of software configuration items that are imported into the actual operating environment in the form of packages ).
2. three libraries are involved in release management:
DSL, definitive software library: the database that stores all approved final software configurations.
the final hardware database (DHS, definitive hardware store) is a region (secure storage) set for the backup hardware ). The components here are used temporarily when a major accident is restored, and should be returned to the final hardware library after use.
CMDB: provides information for release management, and is updated by release management.

Accident Management:
Restore the IT system to the service level defined in the service level agreement as soon as possible, and record incidents to support other processes, minimizing the impact on customer and user business. (Emphasizing accident recovery speed)
1. Incident: events that do not comply with IT service standards that cause or may cause service interruptions and service quality degradation.
Including software and hardware faults, service requests (such as status query, password reset, and Database Export ).
2. When handling multiple accidents at the same time, the priority of accident handling should be determined.
3. Incident escalation: the first-line support (service desk) is upgraded to the second-line support (Management Department), third-line support (software developers), and fourth-line support (providers ).

Problem management:
Investigate and analyze the weaknesses of the IT infrastructure, identify the potential causes of the accident, and develop solutions to the accident and measures to prevent the accident from happening again, reduce the negative impact of problems and accidents on the business to the lowest service management process. (Emphasize identifying the root cause of the accident to develop solutions and Preventive Measures)
1. Problem: before finding out the cause of the accident, the potential cause of the accident is "problem ".
2. Known errors: after finding the root cause of the accident, the problem becomes a well-known error.

Service level management:
Service Level Management (SLM) is a plan, drafting, negotiation, monitoring and reporting for the signing of the Service Level Agreement (SLAs, and a service management process composed of activities such as evaluation of service quality after the service level agreement is signed.
1. Service Level Agreement system:
Three protocols (Service Level Agreement, Operation Level Agreement, support contract) (IT service provider, customer, internal supplier, external third-party supplier ).
A. Service Level Agreement. IT service providers and customers
B. Operational Level Agreement. IT service provider and internal supplier
C. Support contracts. IT service provider and third-party supplier

IT service continuity management:
ensure that IT infrastructure and IT services can be restored within a limited period of time after a disaster occurs (this time should be written in the SLA.
continuity management (itscm) is a process for preventing disasters and enhancing IT Infrastructure Recovery and fault tolerance capabilities, ensure that the Organization has sufficient technology, finance and management resources to ensure the continuity of IT services.
1. disaster (disaster):
external accidents that seriously affect system operation and even cause the system to stop running, such as earthquakes, water fires, theft, terrorist attacks, and cyberattacks, large-scale power outages.
2. Differences from business continuity management:
business continuity management focuses on restoring risks to a reasonable level and business processes after business interruption.
IT service continuity management focuses on the technical aspects of the IT infrastructure.
3. Differences from accident management and problem management:
IT service continuity management focuses on catastrophic incidents that may have a significant impact on the business operations of the Organization.

Financial Management:
Financial Management for IT services is the process of monetizing all the resources involved in the IT service operation. This includes three sub-processes: budgeting, it accounting, and service billing.
Capability Management:
allocates necessary IT resources for IT service operations at reasonable costs based on the current and future business needs of the Organization.
capacity management (capacity management, also known as capacity management)
1. differences from capacity management:
capacity management is a traditional concept in it and network management. The object of measurement is storage space and device performance.
A. Capability Management is an extension of capacity management.
B. Capability Management should not only consider the storage space and equipment performance, but also focus on the support of the overall IT infrastructure service capability to business needs.
C. Capability Management does not aim to achieve high capacity and high performance of devices, but to determine effective capability requirements based on business needs and it costs, so as to design reasonable service capabilities.
2. capability Management mainly solves three problems:
. the cost of maintaining existing IT service capabilities is reasonable for business needs
B. whether the existing IT service capabilities can meet current and future customer needs
C. whether the existing IT service capabilities have achieved optimal performance
3. three sub-processes of Capability Management:
business capability management: focus on the future business needs of the organization for IT services to ensure that such future needs are fully taken into account when developing capability plans.
service capability management: focus on whether the quality of existing IT services can reach the level set in the SLA.
Resource Capability Management: Focus on the capabilities and usage of each component in the IT infrastructure to ensure that the IT infrastructure capability is sufficient to achieve service level goals.

Availability Management:
Availability Management is a service management process that designs, implements, monitors, evaluates, and reports the availability of IT services to ensure continuous service availability.
1. Availability ):
It refers to the ability of a component or a service to provide its functions at a specified time or within a certain period of time. It is usually expressed by the availability.
2. Availability: The time ratio of the service that the customer can actually use within the specified service period
3. Availability-related three features:
Reliability: uninterrupted IT infrastructure
Maintainability: IT infrastructure can be quickly restored after a fault occurs
Security: confidentiality, integrity, and availability of data related to a service

Iii. Implementation
The implementation of ITIL adopts the PDCA implementation method (DAI minhuan was borrowed again here ).
Plan: Determine the target and the process required to achieve the target based on the customer's requirements and relevant policies and regulations to achieve the expected results.
Implementation (DO): The process identified during the planning phase of the implementation.
Check: monitors and reviews the processes implemented and reports the results in accordance with the relevant policies, objectives and requirements.
Act to continuously improve performance.

Appendix:
ITIL framework:

Six modules: business management, service management, IT infrastructure management, security management, IT service management planning and implementation, and application management.

Note: The guide in this document refers to the China IT service management guide.