Online "Book Flights" facility for an airline

Rule Taxonomy

1. Cardinality rules:  data must be present or absent, and/or is restricted in terms of the number of instances.
   
   
1. Mandatory data rules:  one or more data items are required in a particular context.
1. Mandatory data item rules:  a particular single data item must be present.
2. Mandatory option selection rules:  one of a set of pre-defined options must be specified.
3. Mandatory group rules:  at least one of a group of data items must be present.
   
   
2. Prohibited data rules:  a particular data item is not allowed in a particular context.
   
   
3. Singular data rules:  only one instance of a particular data item is allowed in a particular context.
   
   
4. Dependent cardinality rules:  the number of instances of a data item depends on some other data, as in rule statement RS25.
   
   
2. Data content rules:  data is constrained to certain values.
   
   
1. Value set rules:  a data item (or combination of data items) must have a value from a discrete set.
   
   
2. Match rules:  a data item must be the same as or different to some other data item.
   
   
3. Range rules:  a data item must have a value from within a continuous range.
   
   
4. Uniqueness constraints:  a data item (or combination of data items) must be different to other instances of the same data item.
   
   
5. Set constraints:  a set of data items must be the same as some other set of data items.
   
   
6. Data item format rules:  a data item must have a particular format.
   
   
3. Process rules:  occurrences of a process are constrained.
   
   
1. Inter-process interval rules:  an occurrence of a process is constrained as to when it can occur before or after another occurrence of the same process or an occurrence of another process.
   
   
2. Pre-requisite process rules:  a process may only occur if some other process has previously occurred.
   
   
3. Other process pre-conditions:  a process may only occur if some condition (other than the occurrence of a process) has been met.
   
   
4. Structural (definitional) rules:  there are constraints on the structure or definition of a business object of a particular type.
   
   
1. Structural cardinality rules:  there are constraints on the number of components of a particular type in a business object of a particular type, as in rule statements RS117 and RS118.
   
   
2. Data type definition rules:  there are common constraints on the structure or definition of data items of a particular type.
   
   
5. Party rules:  some parties or roles are prohibited from performing some process or activity or playing some role.
   
   
1. Party restriction rules:  there are restrictions onwho can perform some process or activity or play some role, based on age, some other physical characteristic or capability, or appropriate training and testing in the appropriate skills.
   
   
2. Role separation rules:  there is separation of responsibilities, in that the same person is prohibited from performing two particular activities.
   
   
3. Role binding rules:  the person performing the second of two activities must be the person who performed the first of those activities.