ITIL: Difference between revisions
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==See also== | ==See also== | ||
* [[IT Governance]] | * [[IT Governance]] | ||
* [[Microsoft Operations Framework]] (MOF) | * [[Microsoft Operations Framework]] (MOF) | ||
==References== | ==References== |
Revision as of 10:12, 8 September 2011
The Information Technology Infrastructure Library (ITIL®) is a framework of best practice approaches intended to facilitate the delivery of high quality information technology (IT) services. ITIL outlines an extensive set of management procedures that are intended to support businesses in achieving both quality and value, in a financial sense, in IT operations. These procedures are supplier independent and have been developed to provide guidance across the breadth of IT infrastructure, development, and operations.
ITIL is published in a series of books (hence the term Library), each of which covers a core area within IT Management. The names ITIL and IT Infrastructure Library are Registered Trade Marks of the United Kingdom's Office of Government Commerce (OGC). The content of the books is also protected by Crown Copyright.
Certification
ITIL certifications are managed by the ITIL Certification Management Board (ICMB) which is comprised of the OGC, IT Service Management Forum (itSMF) International and two examinations institutes: EXIN (based in the Netherlands) and ISEB (based in the UK).
The EXIN and ISEB administer exams and award qualifications at Foundation, Practitioner and Manager/Masters level currently in 'ITIL Service Management', 'ITIL Application Management' and 'ICT Infrastructure Management' respectively.
A voluntary registry of ITIL-certified practitioners is operated by the ITIL Certification Register.
Organizations or a management system may not be certified as "ITIL-compliant" however an organization that has implemented ITIL guidance in ITSM may be able to achieve compliance with and seek certification under ISO/IEC 20000.
On July 20, 2006, the OGC signed a contract with the APM Group to be its commercial partner for ITIL accreditation from January 1, 2007.
ITIL History
Precursors
Many of the core Service Management concepts did not originate within the original UK Government's Central Computer and Telecommunications Agency (CCTA) project to develop ITIL. IBM claims that its "Yellow Books" (A Management System for the Information Business) were key precursors. According to IBM:
- "In the early 1980s, IBM documented the original Systems Management concepts in a four-volume series called A Management System for Information Systems. These widely accepted “yellow books,” ... were key inputs to the original set of ITIL books."
The primary author of the IBM Yellow Books was Edward A. Van Schaik, who compiled them into the 1985 book Management System for the Information Business. In the 1985 work, Van Schaik in turn references a 1974 Richard L. Nolan work, Managing the Data Resource Function which may be the earliest known systematic English-language treatment of the topic of large scale IT management (as opposed to technological implementation questions).
Other IBM Publications and comments by ITIL authors clarify that the "Yellow Books" were a significant input to ITIL Service Support but the Service Delivery volume didn't draw on them to the same extent.
Further evidence on this (pro or con) is lacking, but the ongoing involvement of IBM (as well as many other vendors and consultants) in ITIL authorship is a matter of record, visible in the front matter of the ITIL volumes.
Development
What is now called ITIL version 1, developed under the auspices of the CCTA was entitled "Government Information Technology Infrastructure Management Methodology" (GITMM) and over several years eventually expanded to 31 volumes in a project initially directed by Peter Skinner and John Stewart (CCTA) at the CCTA. The publications were retitled primarily as a result of the desire (by Roy Dibble of CCTA) that the publications be seen as guidance and not as a formal method and as a result of growing interest from outside of the UK Government.
Although developed during the 1980s, ITIL was not widely adopted until the mid 1990s. This wider adoption and awareness has led to a number of standards, including ISO/IEC 20000 which is an international standard covering the IT Service Management elements of ITIL. ITIL is often considered alongside other best practice frameworks such as the Information Services Procurement Library (ISPL), the Application Services Library (ASL), Dynamic Systems Development Method (DSDM), the Capability Maturity Model (CMM/CMMI), and is often linked with IT governance through Control Objectives for Information and related Technology (COBIT).
In December 2005, the OGC issued notice of an ITIL refresh, commonly known as ITIL v3, which is planned to be available in Spring 2007. ITIL v3 publication is expected to initially include five core texts namely:
- IT Service Design
- IT Service Introduction
- IT Service Operations
- IT Service Improvement
- IT Service Strategies
These publications will consolidate much of the current v2 Service Lifecycle practices.
ITIL alternatives
IT Service Management as a concept is related but not equivalent to ITIL which contains a subsection specifically entitled IT Service Management (ITSM). The combination of the Service Support and Service Delivery volumes are a specific example of the ITIL ITSM framework which is currently embodied in the ISO/IEC 20000 standard (previously BS 15000).
Outside of ITIL, other IT Service Management approaches and frameworks exist, including the Enterprise Computing Institute's library covering general issues of large scale IT management, including various Service Management subjects.
The British Educational Communications and Technology Agency (BECTA) has developed the Framework for ICT Technical Support (FITS) and is based on ITIL, but it is slimmed down for UK primary and secondary schools (which often have very small IT departments). Similarly, The Visible OPS Handbook: Implementing ITIL in 4 Practical and Auditable Steps claims to be based on ITIL but to focus specifically on the biggest "bang for the buck" elements of ITIL.
Smaller organizations that cannot justify the expense of a full ITIL program and materials can gain insight into ITIL from a review of the Microsoft Operations Framework which is based on ITIL but defines a more limited implementation.
Overview of the Library
The IT Infrastructure Library originated as a collection of books each covering a specific practice within IT Service Management. After the initial publication, the number of books quickly grew within ITIL v1 to over 30 volumes. In order to make ITIL more accessible (and affordable) to those wishing to explore it, one of the aims of ITIL v2 was to consolidate the publications into logical 'sets' that grouped related process guidelines into the different aspects of IT management, applications and services.
While the Service Management sets (Service Support and Service Delivery) are by far the most widely used, circulated and understood of ITIL publications, ITIL provides a more comprehensive set of practices as a whole. Proponents believe that using the broader library provides a comprehensive set of guidance to link the technical implementation, operations guidelines and requirements with the strategic management, operations management and financial management of a modern business.
The eight ITIL books and their disciplines are:
The IT Service Management sets
Other operational guidance
- 3. ICT Infrastructure Management
- 4. Security Management
- 5. The Business Perspective
- 6. Application Management
- 7. Software Asset Management
To assist with the implementation of ITIL practices a further book was published providing guidance on implementation (mainly of Service Management):
And this has more recently been supplemented with guidelines for smaller IT units, not included in the original eight publications:
- 9. ITIL Small-Scale Implementation
ITIL is built around a process-model based view of controlling and managing operations often credited to W. Edwards Deming. The ITIL recommendations were developed in the 1980s by the UK Government's CCTA in response to the growing dependence on IT and a recognition that without standard practices, government agencies and private sector contracts were independently creating their own IT management practices and duplicating effort within their Information and Communications Technology (ICT) projects resulting in common mistakes and increased costs. In April, 2001 the CCTA was merged into the Office of Government Commerce (OGC), which is an Office of the United Kingdom's HM Treasury and disappeared as a distinct organization.
One of the primary benefits claimed by proponents of ITIL within the IT community is its provision of common vocabulary, consisting of a glossary of tightly defined and widely agreed terms. A new and enhanced glossary has been developed as a key deliverable of the ITIL v3. also known as the ITIL Refresh Project.
Details of the ITIL Framework
Service Support
The Service Support ITIL discipline is focused on the User of the ICT services and is primarily concerned with ensuring that they have access to the appropriate services to support the business functions.
To a business, customers and users are the entry point to the process model. They get involved in service support by:
- Asking for changes
- Needing communication, updates
- Having difficulties, queries.
The service desk is the single contact point for the customers to record their problems. It will try to resolve it, if there is a direct solution or will create an incident. Incidents initiate a chain of processes: Incident Management, Problem Management, Change Management, Release Management and Configuration Management (see following sections for details). This chain of processes is tracked using the Configuration Management Database (CMDB), which records each process, and creates output documents for traceability (Quality Management).
Service Desk
This function is the single point of contact between users and IT Service Management.
Tasks include handling incidents and requests, and providing an interface for other ITSM processes.
- Single Point of Contact (SPOC) and not necessarily the First Point of Contact (FPOC)
- There is a single point of entry and exit
- Easier for Customers
- Data Integrity
- Communication channel is streamlined
The primary functions of the Service Desk are :
Incident Control : life cycle management of all Service Requests
Communication : keeping the customer informed of progress and advising on workarounds
The Service Desk function is known under various names :
Call Center: main emphasis on professionally handling large call volumes of telephone-based transactions
Help Desk: manage, co-ordinate and resolve incidents as quickly as possible
Service Desk: not only handles incidents, problems and questions but also provides an interface for other activities such as change requests, maintenance contracts, software licenses, Service Level Management, Configuration Management, Availability Management, Financial Management and IT Services Continuity Management
The three types of structure that can be considered are :
Local Service Desk: to meet local business needs - is practical only until multiple locations requiring support services are involved
Central Service Desk: for organizations having multiple locations - reduces operational costs and improves usage of available resources
Virtual Service Desk: for organizations having multi-country locations - can be situated and accessed from anywhere in the world due to advances in network performance and telecommunications, reducing operational costs and improving usage of available resources
Note: Service Desk is a function and not a process; as there is no manipulation of input for output.
Incident Management
The goal of Incident Management is to restore services as quickly as possible with minimal disruption to users
Problem Management
The goal of Problem Management is to resolve the root cause of incidents and thus to minimize the adverse impact of incidents and problems on business that are caused by errors within the IT infrastructure, and to prevent recurrence of incidents related to these errors. A `problem' is an unknown underlying cause of one or more incidents, and a `known error' is a problem that is successfully diagnosed and for which a work-around has been identified. The CCTA defines problems and known errors as follows:
- A problem is a condition often identified as a result of multiple Incidents that exhibit common symptoms. Problems can also be identified from a single significant Incident, indicative of a single error, for which the cause is unknown, but for which the impact is significant.
- A known error is a condition identified by successful diagnosis of the root cause of a problem, and the subsequent development of a Work-around.
Problem management is different from incident management. The principal purpose of problem management is find and resolve the root cause of a problem and prevention of incidents; the purpose of incident management is to return the service to normal level as soon as possible, with smallest possible business impact.
The problem management process is intended to reduce the number and severity of incidents and problems on the business, and report it in documentation to be available for the first-line and second line of the help desk. The proactive process identifies and resolves problems before incidents occur. These activities are:
- Trend analysis;
- Targeting support action;
- Providing information to the organization.
The Error Control Process is an iterative to process known errors until they are eliminated by the successful implementation of a change under the control of the Change Management process.
The Problem Control Process aims to handle problems in an efficient way. Problem control identifies the root cause of incidents and reports it to the service desk. Other activities are:
- Problem identification and recording;
- Problem classification;
- Problem investigation and diagnosis.
The standard technique for identifying the root cause of a problem is to use an Ishikawa diagram, also referred to as a cause-and-effect diagram, tree diagram, or fishbone diagram. An Ishikawa diagram is typically the result of a brainstorming session in which members of a group offer ideas to improve a product. For problem-solving, the goal will be to find the cause and effect of the problem.
Ishikawa diagrams can be defined in a meta-model.
First there is the main subject, it's the backbone of the diagram what we try to solve or improve, the main subject is derived from a cause. The relationship between a cause and an effect is a double relation: an effect is a result of a cause, and the cause is the root of an effect. But there is just one effect for several causes and one cause for several effects.
Configuration Management
Configuration Management is a process that tracks all of the individual Configuration Items (CI) in a system.
Change Management
A change is “an event that results in a new status of one or more configuration items (CI's)”
Manage approved, cost effective, business enhancing changes (fixes) - with minimum risk to IT infrastructure.
The goal of Change Management is to ensure that standardized methods and procedures are used for efficient handling of all Changes, in order to minimize the impact of Change-related incidents and to improve day-to-day operations.
The main aims of Change Management are :
- Minimal disruption of services
- Reduction in back-out activities
- Economic utilization of resources involved in the change
Change Management Terminology
Change: the addition, modification or removal of CIs
Request for Change (RFC): form used to record details of a request for a change and is sent as an input to Change Management by the Change Requestor
Forward Schedule of Changes (FSC): schedule that contains details of all the forthcoming Changes
Release Management
Release Management is used for platform-independent and automated distribution of software and hardware, including license controls across the entire IT infrastructure. Proper Software and Hardware Control ensure the availability of licensed, tested, and version certified software and hardware, which will function correctly and respectively with the available hardware. Quality control during the development and implementation of new hardware and software is also the responsibility of Release Management. This guarantees that all software can be conceptually optimized to meet the demands of the business processes. The goals of release management are:
- Plan to roll-out of software
- Design and implement procedures for the distribution and installation of changes to IT systems
- Effectively communicate and manage expectations of the customer during the planning and roll-out of new releases
- Control the distribution and installation of changes to IT systems
The focus of release management is the protection of the live environment and its services through the use of formal procedures and checks.
Release Categories
A Release consists of the new or changed software and/or hardware required to implement approved Changes
Releases are categorized as :
- Major software Releases and hardware upgrades, normally containing large areas of new functionality, some of which may make intervening fixes to Problems redundant. A major upgrade or Release usually supersedes all preceding minor upgrades, Releases and emergency fixes
- Minor software Releases and hardware upgrades, normally containing small enhancements and fixes, some of which may have already been issued as emergency fixes. A minor upgrade or Release usually supersedes all preceding emergency fixes
- Emergency software and hardware fixes, normally containing the corrections to a small number of known Problems
Releases can be divided based on the release unit into :
- Delta Release : is a release of only that part of the software which has been changed. For ex: Security patches to plug bugs in a software
- Full Release : means that the entire software program will be release again. For ex : an entire version of an application
- Packaged Release : is a combination of many changes . For ex : an Operating System image containing the applications as well
Service Delivery
The Service Delivery discipline is primarily concerned with the proactive and forward-looking services that the business requires of its ICT provider in order to provide adequate support to the business users. It is focused on the business as the Customer of the ICT services (compare with: Service Support). The discipline consists of the following processes, explained in subsections below:
- Service Level Management
- Capacity Management
- IT Service Continuity Management
- Availability Management
- Financial Management
Service Level Management
Service Level Management provides for continual identification, monitoring and review of the levels of IT services specified in the Service Level Agreements (SLAs). Service Level Management ensures that arrangements are in place with internal IT support providers and external suppliers in the form of Operational Level Agreements (OLAs) and Underpinning Contracts (UpCs). The process involves assessing the impact of change upon service quality and SLAs. The service level management process is in close relation with the operational processes to control their activities. The central role of Service Level Management makes it the natural place for metrics to be established and monitored against a benchmark.
Service Level Management is the primary interface with the Customer (as opposed to the User who is serviced by the Service Desk). Service Level Management is responsible for
- ensuring that the agreed IT services are delivered when and where they are supposed to be
- liaising with Availability Management, Capacity Management, Incident Management and Problem Management to ensure that the required levels and quality of service are achieved within the resources agreed with Financial Management
- producing and maintaining a Service Catalog (a list of standard IT service options and agreements made available to Customers)
- ensuring that appropriate IT Service Continuity plans have been made to support the business and its continuity requirements.
The Service Level Manager relies on all the other areas of the Service Delivery process to provide the necessary support which ensures the agreed services are provided in a cost effective, secure and efficient manner.
Capacity Management
Capacity management supports the optimum and cost effective provision of IT services by helping organizations match their IT resources to the business demands. The high-level activities are Application Sizing, Workload Management, Demand Management, Modeling, Capacity Planning, Resource Management, and Performance Management.
IT Service Continuity Management
IT Service Continuity Management helps to ensure the availability and rapid restoration of IT services in the event of a disaster. The high level activities are Risk Analysis, Manage Contingency Plan Management, Contingency Plan Testing, and Risk Management.
Availability Management
Availability Management allows organizations to sustain the IT service availability in order to support the business at a justifiable cost. The high-level activities are Realize Availability Requirements, Compile Availability Plan, Monitor Availability, and Monitor Maintenance Obligations.
Availability Management is the ability of an IT component to perform at an agreed level over a period of time.
- Reliability: how reliable is the service? Ability of an IT component to perform at an agreed level at described conditions.
- Maintainability: The ability of an IT Component to remain in, or be restored to an operational state.
- Serviceability: The ability for an external supplier to maintain the availability of component or function under a third party contract
- Resilience: A measure of freedom from operational failure and a method of keeping services reliable. One popular method of resilience is redundancy.
- Security: A service has associated data. Security refers to the confidentiality, integrity, and availability of that data
Financial Management for IT Services
Planning To Implement Service Management
The ITIL discipline - Planning To Implement Service Management attempts to provide practitioners with a framework for the alignment of business needs and Information Technology provision requirements. The processes and approaches incorporated within the guidelines suggest the development of a Continuous Service Improvement Program (CSIP) as the basis for implementing other ITIL disciplines as projects within a controlled, program of work. Planning To Implement Service Management is mainly focused on the Service Management processes, but also generically applicable to other ITIL disciplines.
An approach to implement or improve service management is the Continuous Service Improvement Program (CSIP). This program consists of the following steps regarding one single improvement:
- create vision
- analyze organization
- set goals
- implement IT service management
- measure progress towards goals using Key Performance Indicators (KPI)
Security Management
The ITIL-process Security Management describes the structured fitting of information security in the management organization. ITIL Security Management is based on the code of practice for information security management also known as ISO/IEC 17799.
A basic concept of the Security Management is the information security. The primary goal of information security is to guarantee safety of the information. Safety is to be protected against risks. Security is the means to be safe against risks. When protecting information it is the value of the information that has to be protected. These values are stipulated by the confidentiality, integrity and availability. Inferred aspects are privacy, anonymity and verifiability.
The current move towards ISO/IEC 27001 may require some revision to the ITIL Security Management best practices which are often claimed to be rich in content for physical security but weak in areas such as software/application security and logical security in the ICT infrastructure.
ICT Infrastructure Management
ICT Infrastructure Management processes recommend best practice for requirements analysis, planning, design, deployment and ongoing operations management and technical support of an ICT Infrastructure. ("ICT" is an acronym for "Information and Communication Technology".)
The Infrastructure Management processes describe those processes within ITIL that directly relate to the ICT equipment and software that is involved in providing ICT services to customers.
- ICT Design and Planning
- ICT Deployment
- ICT Operations
- ICT Technical Support
These disciplines are less well understood than those of Service Management and therefore often some of their content is believed to be covered 'by implication' in Service Management disciplines.
ICT Design and Planning
ICT Design and Planning provides a framework and approach for the Strategic and Technical Design and Planning of ICT infrastructures. It includes the necessary combination of Business (and overall IS) strategy, with technical design and architecture. ICT Design and Planning drives both the Procurement of new ICT solutions through the production of Statements of Requirement ("SOR") and Invitations to Tender ("ITT") and is responsible for the initiation and management of ICT Program for strategic business change. Key Outputs from Design and Planning are:
- ICT Strategies, Policies and Plans
- The ICT Overall Architecture & Management Architecture
- Business Cases, Feasibility Studies, ITTs and SORs
ICT Deployment Management
ICT Deployment provides a framework for the successful management of design, build, test and roll-out (deploy) projects within an overall ICT program management. It includes many project management disciplines in common with Prince2, but has a broader focus to include the necessary integration of Release Management and both functional and non functional testing.
ICT Operations Management
ICT Operations Management provides the day-to-day technical supervision of the ICT infrastructure. Often confused with the role of Incident Management from Service Support, Operations is more technical and is concerned not solely with Incidents reported by users, but with Events generated by or recorded by the Infrastructure. ICT Operations may often work closely alongside Incident Management and the Service Desk, which are not-necessarily technical in order to provide an 'Operations Bridge'. Operations, however should primarily work from documented processes and procedures and should be concerned with a number of specific sub-processes, such as: Output Management, Job Scheduling, Backup and Restore, Network Monitoring/Management, System Monitoring/Management, Database Monitoring/Management Storage Monitoring/Management. Operations are responsible for:
- A stable, secure ICT infrastructure
- A current, up to date Operational Documentation Library ("ODL")
- A log of all operational Events
- Maintenance of operational monitoring and management tools.
- Operational Scripts
ICT Technical Support
ICT Technical Support is the specialist technical function for infrastructure within ICT. Primarily as a support to other processes, both in Infrastructure Management and Service Management, Technical Support provides a number of specialist functions: Research and Evaluation, Market Intelligence (particularly for Design and Planning and Capacity Management), Proof of Concept and Pilot engineering, specialist technical expertise (particularly to Operations and Problem Management), creation of documentation (perhaps for the Operational Documentation Library or Known Error DataBase).***
The Business Perspective
The Business Perspective is the name given to the collection of best practices that is suggested to address some of the issues often encountered in understanding and improving IT service provision, as a part of the entire business requirement for high IS quality management. These issues are:
- Business Continuity Management describes the responsibilities and opportunities available to the business manager to improve what is, in most organizations one of the key contributing services to business efficiency and effectiveness.
- Surviving Change. IT infrastructure changes can impact the manner in which business is conducted or the continuity of business operations. It is important that business managers take notice of these changes and ensure that steps are taken to safeguard the business from adverse side effects.
- Transformation of business practice through radical change helps to control IT and to integrate it with the business.
- Partnerships and outsourcing
This volume is related to the topics of IT Governance and IT Portfolio Management.
Application Management
ITIL Application Management set encompasses a set of best practices proposed to improve the overall quality of IT software development and support through the life-cycle of software development projects, with particular attention to gathering and defining requirements that meet business objectives.
This volume is related to the topics of Software Engineering and IT Portfolio Management.
Software Asset Management
Organizations rely increasingly on technology in order to operate profitably and software as such should be treated as a valuable asset. Good Software Asset Management achieved through Best Practice enables organizations to save money through effective policies and procedures which are continuously reviewed and improved.
Software Asset Management is a part of overall IT Service Management best illustrated by the IT Infrastructure Library (ITIL) guides, which is the mostly widely accepted approach to providing a comprehensive and consistent set of best practices.
Definition taken from the ITIL guide to SAM ”Software Asset Management is all of the infrastructure and processes necessary for the effective management, control and protection of the software assets within an organization, throughout all stages of their life-cycle.”
Benefits
Benefits from well managed software assets can be achieved from simple yet effective changes for example:
Saving money on licensing costs by increasing widespread use of volume licensing agreements. By centralizing the procurement, organizations ensure they buy only what is needed and get the best possible price.
With an effective SAM plan in place, an organization knows exactly what software and hardware is installed on the network, making it easier to identify what is needed to manage technological change, and easier to protect and secure your data through effective patch management.
Where possible, it is recommended to standardize desktops, which will lead to reduced training, support costs and incompatibility between applications.
Process
The overall SAM process essentially falls into four distinct stages:
- Preparation (Workshop)
- Getting there (Review)
- Staying there (Implementation)
- Proving that you are staying there (Health check)
One person within the organization should be involved in all stages and be responsible for the ongoing efficiency of the SAM processes. However it is, equally as important that external consultation is sought to sanity check and review any improvement and help build on them.
Small-Scale Implementation
ITIL Small-Scale Implementation provides an approach to the implementation of the ITIL framework for those with smaller IT units or departments. It is primarily an auxiliary work, covering many of the same best practice guidelines as Planning To Implement Service Management, Service Support and Service Delivery but provides additional guidance on the combination of roles and responsibilities and avoiding conflict between ITIL priorities.
Criticisms of ITIL
ITIL has come in for criticism on several fronts. Criticisms include:
- Accusations that many ITIL advocates think ITIL is "a holistic, all-encompassing framework for IT governance";
- Accusations that proponents of ITIL indoctrinate the methodology with 'religious zeal' at the expense of pragmatism.
As Jan van Bon (author and editor of many IT Service Management publications) notes,
- There is a lot of confusion about ITIL, stemming from all kinds of misunderstandings about its nature. ITIL is, as the OGC states, a set of best practices. The OGC doesn’t claim that ITIL’s best practices describe pure processes. The OGC also doesn’t claim that ITIL is a framework, designed as one coherent model. That is what most of its users make of it, probably because they have such a great need for such a model...
CIO Magazine columnist Dean Meyer has also presented some cautionary views on the framework, including five pitfalls such as "becoming a slave to outdated definitions" and "Letting ITIL become religion." As he notes, "...it doesn't describe the complete range of processes needed to be world class. It's focused on ... managing ongoing services."
The quality of the library's volumes is seen to be uneven. For example, van Herwaarden and Grift note, “the consistency that characterized the service support processes … is largely missing in the service delivery books."
In a 2004 survey designed by Noel Bruton (author of 'How to Manage the IT Help-desk' and 'Managing the IT Services Process'), ITIL adopting organizations were asked to relate their actual experiences in having implemented ITIL. Seventy-seven percent of survey respondents either agreed or strongly agreed that "ITIL does not have all the answers". ITIL exponents accept this, citing ITIL's stated intention to be non-prescriptive, expecting that organizations will have to engage ITIL processes with their existing overall process model. Bruton notes that the claim to non-prescriptiveness must be at best one of scale rather than than absolute intention, for the very description of a certain set of processes is in itself a form of prescription. (Survey "The ITIL Experience - Has It Been Worth It", author Bruton Consultancy 2004, published by Help-desk Institute Europe, The Help-desk and IT Support Show and Hornbill Software.)