The rule builder's role

The goal of IDIOM is to allow business people to build and manage the business rules. Rules builders are charged with managing decisions and formulas and need have no knowledge of the technical architecture or environment. The rules they develop are technology agnostic: it makes no difference which programming language is generated or how the generated code is integrated into the application. The organisation’s rules are maintained in just one place and can be deployed to multiple applications using whatever languages and technologies are necessary.

Rule builders use the IDIOM decision Suite to create repositories of business rules. They work independently of the application developers, having agreed at the outset on a “contract” defined by a series of XML schemas describing the objects contained in the decision requests that pass between the application and the IDIOM Decision Service at execution time. The business rules that they develop take the form of decisions and formulas closely integrated with the schemas.

Developing schemas

The schemas are the starting point for building an idiom rules repository. They emerge from a conventional analysis and design process in which some additional focus has been placed on decisions. For example, use case writers recognise that the application modules which will implement the use cases will at runtime delegate decision making to the idiom Decision Service, and specifically identify decisions in the use cases accordingly. Typically the decisions are factored out into a separate “decision inventory” where they can be analysed, managed and reused more effectively.

More detailed analysis of the decisions leads to the definition of the input and output data for each decision request, and a final formal specification using XML schemas. This is a technical design task for the system’s architects, who must also consider the integration of the decision requests into the software architecture.

Preparing the IDIOM repository

A technically inclined administrator prepares the repository by loading the schemas and performing other administrative tasks, such as defining users and workgroups. Before being presented to the rules builders schemas undergo some simplification and customization. IDIOM renders XML schemas to remove unnecessary complexity and to allow the user to deal with a normalised and familiar view of the world. All includes, complex types, and other sophisticated schema modifiers are resolved, and a normalised tree structure is produced in which elements and attributes are presented simply as nodes. An IDIOM rendered schema is a simple structure having a single root and a fully expanded tree of nodes, which can be presented to the user in an intuitively clear and simple hierarchical format.

To further reduce complexity IDIOM provides an opportunity for the administrator to filter the raw schema down to a selected set of nodes, so that the rules builders see only those sections of the domain that are truly relevant for them. This comfort zone can also be extended by renaming nodes with aliases, so that local terminology can be used if preferred.