EIAxpert is embedded in a more generic Management Information System, document management, and work flow support, designed to manage a large number of Impact Statement, projects, and scenarios.

The system is implemented as a web-based decision support system; it is organised in terms of a few major OBJECT CLASSES:

• Applications   are the central object classs;
  they represent the central "unit of work" and organization with the associated administrative and scheduling (work flow) data such as
  • the responsible analysts,
  • scheduling and status information,
  • contacts such as project proponent, client, regulatory authority,
  • resultin communications structure like mailing lists
  • applicable regulatory framework,
  • documents, imagery, maps
  
  Applications are a containers for the set of project (scenarios) specific instances of a (generic) Application Domain: the actual assessments, that may combine into Preliminary Impact Statement or a full fledged Report.

  An application is further defined by

  1. Application domain that defines the conceptual framework;
  2. Project - the very reason for the assessment - which defines the physical, techno-economic and socio-cultural, and geographicalenvironmental framework; Projects have generic data (a subset of the Application's administrative data), and they can be represented
     • as one or more alternatives,
       • including a zero alternative (no project, the environmental baseline)
       • any number of project variants.
     • One or more Locations that define the

  Application Domains   define a particular yet generic environmental problem or regulatory framework for one or more applications (to particular projects), defined in terms of the hierarchy of problem classes and their component problems that they must consider.

  A Problem Domain is defined by a (user defined and selected) list of problem classes. These are selected from a common masterlist of problem classes.

• Problem classes   are groupings of individual problems that have some common denominator, shared theme or topic, relate to the project implementation schedule or environmental media, socio-economic aspects.
  These problem classes are often defined by a particular EIA strategy, guidelines, or the applicable regulatory framework.

• Problems are represented by a "target variable" (of the backward chaining inference) which is assigned a status to represent the assessment of this particular, potential problem in the current
  • problem domain
  • project (and specific scenario, if applicable)
  • at the location corresponding to that scenario.

  Individual problems are described by two bocks of hypertext, representing for example, descriptions of

  • Impact and mitigation (most EIA strategies)
  • Status and implementation strategy (ISO 14000)

  Problem assessment: the backward chaining inference to define the status or assessment of the problem uses first-order production RULES (basic IF - THEN logic with arbitrary nesting) that derives this rule-based assessment (the target variables value) from

  • project characteristics (pre-defined or user supplied)
  • location characteristsics (pre-defined or user supplied)
  • possble mitigation strategies a user can choose as part of a project variant or scenario;
  • the analysist know-how in the assessment, represented by selecting or skipping specific rules.
  Target values to make it possible to
  • summarize problems with problem classes
  • compare scenarios or project variants
  The structure of the target Descriptors (variables associated with each problem) must be the same in terms of
  • number of symbolic values
  • order of interpretation from "good" to "bad" and a possible "not applicable" or "unknown".

Projects   are specific development activities that require an impact assessment. They fall into one of the domains, are well defined in space and time, alwasy have a zero alternative (no project) and a baseline (the default project variant) and may have several more variants or alternatives, scenarios, that need to be compared and ranked; projects are defined by their proponent, location (alternative locations define possible scenarios) administrative data, and project specific data that are related to the problem classes and individual problems, their target indicators and all the input information required for the assessment.

Locations   describe the physical locations of projects; There may be several alternative locations for a project (but any alternative or scenario can have only one), and there may be more than one project planned for the same location - which may include the need for the assessment of cumulative affects and interactions. Locations are defined by any number of georeferenced properties.

Comparison  the main comparison is in terms of the problem values.