There are some phrases and expressions that turn up in such a high number of news stories, articles and every day conversations (at least in the IT arena) that one is forced to question whether people are being paid to use them. Often these terms are used as a form of verbal shorthand to capture complex, or at least long-winded, ideas or processes and put them into a format that does not physically exhaust the user.

However, occasionally a turn of phrase moves into everyday use with little common understanding of what it really means or seeks to convey. This is just the scenario that we currently have with the expression Quality of Service. Just what does it mean? Does it have the same meaning for everyone? Does it posses any real value at all?

At the moment it appears that Quality of Service (QoS) has managed to capture a space in the hearts and larynxes of nearly everyone connected with IT. Managers can be heard discussing how they can improve the quality of the services that they deliver to their users whilst many IT vendors happily tell the world how the use of their products and services invariably supply improvements in the quality level of services. Of course, one must not forget that service delivery organisations, commonly known as Outsourcers, have never been know to say that they cannot improve on the level of service experienced by end users. But the question still remains, what does Quality of Service really mean?

At the simplest level, some people define QoS in terms of Service Level Agreements (SLAs). Philosophically this approach has some merit but it tends to be let down badly by the poor fashion in which many SLAs are detailed. It is by no means unusual to see SLAs defined solely in terms of the hours of operation of a service and the percentage of time that systems will be up and running within those working hours. Whilst there is a clear need to provide access to services during the hours that the users of the service need to work, this measurement alone is not enough. SLAs need to concentrate on the issues that are important to the user of the service. This will include hours that the service is available but may also require some indication of the performance of the system as experienced by the user and measurements of the support that the user can expect to receive if they require assistance.

The important point is that it is the end user's experience of the service that needs to be measured and that must form the basis of the service level. The metrics used must be for the whole service, the end to end experience and not just cover the individual components of the IT infrastructure that supports the real business process. Performance measurements of the infrastructure's components have value to the IT Support team, not to end users who neither understand them nor desire to see them.

The conclusion is that Quality of Service means different things to different people. However, to provide value to any business, QoS must measure service from the end users perspective and must reflect real business processes and requirements. If people can begin to work towards this we may begin to hear some meaningful discussions on how to improve quality of service and not just some marketing speak from an IT vendor or outsourcing organisation.