The use of Zero reference level is done in order to avoid errors in the measurement of Voltage in various points of a circuit. The Zereo reference level or the common point is considered to be of zero potential and all other circuit voltages weather positive or negative , are measured with respect to this Common or Zero Reference Level. There is no hard and fast rule for the selection of the common point or Zero Reference Level , any point in the circuit can be regarded as the Zero Reference level and all the electronics theorems and theorems will be still true in the circuit if all the measurements are done correctly with respect to the common point. For example: Case I: In the Image Above: The point shown or the negative terminal of the battery is regarded as the Common Zero Reference Level. Then , the potential of the given points are as follows: A:- 0 Voltage B:- 7 Voltage ( Just a Guess) C:- 12 Voltage Case II: We can also equally now regard the point B as the Zero reference level as shown in the figure:
Zero Level support, or 0-level support, is a term for a support concept which involves using web-based self-service as a stage before the traditional first-line support. Zero Level support frees up time and resources for manned support and allows support to be provided more quickly. One consequence of the introduction of Zero Level support is that the right types of issues are directed to the right support channels. Web-based self-service does away with the simple, recurring issues which users could ideally resolve themselves. Zero Level support is effective as an internal form of support for employees within a company, but it is also effective as a form of external support for clients.
I recommend that you allocate a Content Manager role to someone on the service desk. This then makes them responsible for ensuring that the content in Zero Level support documents is always up to date and correct. It is also a good idea to introduce a procedure which involves production of new guides in all instances where they would be expected to answer most questions before new services are rolled out within an organisation, when they are needed most. This procedure may work so that a system owner, for example, provides unprocessed basic material produced by him or him or which has come directly from an external supplier, and distributes it to a Content Manager who is responsible for ensuring that suitable guides are produced and available when the IT service or program is rolled out to end-users or clients.