A relationship describes the dependency or connectivity between
configuration items. A relationship can be either unidirectional or bidirectional. The
results of a search are affected when relationships are bidirectional or unidirectional.
A unidirectional relationship
is valid in only one direction. The following phrases are examples of unidirectional
relationships: installed on, installed with, contains, member of, starts from,
resides on, succeeded by, and preceded by.
For example, an operating system is installed on a computer. A computer
is not installed on an operating system. However, in another type of unidirectional
relationship, you can specify that a computer contains an operating system.
A bidirectional relationship
is valid in both directions. Intersects is an example of a bidirectional relationship.
The distinction between
unidirectional relationships and bidirectional relationships is important
when you search configuration items based on relationships.
- A user searches for all configuration items with an interfaces with relationship
to application Z. Since interfaces with is a bidirectional relationship, the
search program searches for these occurrences:
- The source configuration item is application Z and the relationship is
- The target configuration item is application Z and the relationship is
- For unidirectional relationships, the search program searches for one
combination. For example, a user searches for all configuration items with
a member of relationship to an EMAIL SERVICE application, where EMAIL SERVICE
is the target configuration item. The search program searches for the following
occurrence: the target configuration item is EMAIL SERVICE and the relationship
is member of.
- You can define one unidirectional relationship to be complementary to
another unidirectional relationship. For example, in your relationship definition,
you specify that installed on is complementary to installed with. A user wants
to find all configuration items that are installed on AppServer K. The search
program searches for these occurrences:
- The target configuration item is AppServer K and the relationship is installed
- The source configuration item is AppServer K and the relationship is installed