Business rules play a critical role during decision making when executing business processes. Existing modelling techniques for business rules offer modellers guidelines on how to create models that are consistent, complete and syntactically correct. However, modelling guidelines that address manageability in terms of anomalies such as insertion, update and deletion are not widely available. This paper presents a normalisation procedure that provides guidelines for managing and organising business rules. The procedure is evaluated by means of an experiment based on existing case study material. Results show that the procedure is useful for minimising insertion and deletion anomalies.
A formal description of a database consists of the description of the relations (tables) of the database together with the constraints that must hold on the database. Furthermore the contents of a database can be retrieved using queries. These constraints and queries for databases can very well be formalized. A formal description of a constraint or a query is necessary to describe the constraint or query unambiguously. In other words, a formal description leads to one and only one meaning of the constraint or query. To describe constraints and queries in a formal way we use predicate logic, set theory and tuple relational calculus. The tuple relational calculus is a calculus based on the use of tuple variables. A tuple variable is a variable that ranges over a named relation (i.e. a set of tuples of a relation). This paper describes the use of the relational calculus for databases. A description of the formal notation is given as well as a mapping of these expressions to SQL.
