8. Technical framework

8.1. About this section

This section sets out a layer model that helps to classify the standards listed in the following section.

8.2. Layer Model

Layer models are widely used to classify functions within IT systems. The intent is to simplify systems by segregating system functions into levels and disentangling the complexity and variations of each level. Components normally communicate only with others at neighbouring levels, and in standardised ways.

The model for this version of the e-GIF is below.

e-GIF v2 Layer Model

The components of this model are:

Network - This layer covers details of data transport such as network protocols. This is crucial area for interoperability. Without agreement on networking standards it is hard or impossible to make systems communicate. The e-GIF uses a subset of the widely proven Internet protocol suite.

Architecture - This defines the way in which data is represented, at a purely syntactic level. The e-GIF contains the XML standard for marking data elements, and a version of the Unicode standard which allows for representing non-Roman characters such as those with macrons. This layer also covers processes when expressed in purely technical terms.

Business Services - The meaning of the data - how a stream of data is mapped to usable business information. This depends on the type of information being represented. The e-GIF includes, for example, a standard way of representing a name and address as a stream of XML data.

Access and presentation - Standards and guidelines covering how business systems are presented and accessed by users. Much of the content of the Government Web Guidelines fit here.

Security - Security is shown as crossing all layers to reflect the fact it needs to be designed in to a system, not added as a layer on top. The e-GIF contains standards at the various levels designed to offer different levels of security as appropriate. It also refers to a series of standards and policy statements (the NZSITs) which provide advice and direction on the levels of required.

E-government components - These are actual implementations of IT infrastructure made available for use by public sector agencies as part of the EGU Component Architecture initiative.

Two further layers are vital but not shown in the diagram for clarity, as they support all the others. They are Management and Governance.