Purpose

The

Concept
ShowParts term t 900000000000534007|Module dependency reference set|

represents dependencies between different

Gloss
PreSpace false t SNOMED CT

release

Gloss
PreSpace false t modules

. In each case, the dependency indicates which

Specref
RefType (field) t targetEffectiveTime

of each particular

Gloss
PreSpace false t module

a given

Specref
RefType (field) t sourceEffectiveTime

of the dependent

Gloss
PreSpace false t module

requires.

Data structure

The

Glossconcept
t 900000000000534007|Module dependency reference set|

is  is a

Specref
RefType (data type) t String

-

Specref
RefType (data type) t String

Gloss
PreSpace false t reference set

which is used to represent dependencies between

Gloss
PreSpace false t modules

, taking account of

Gloss
PreSpace false t module

versioning. Its structure is shown in the following table.

...

Field

...

Data type

...

Purpose

...

...

id

...

...

...

NO

...

Specref
RefType (field) t effectiveTime

...

Specref
RefType (data type) t Time

...

The inclusive date or time at which this version of the identified

Gloss
Space true t reference set member

became the current version.

The current version of this

Gloss
Space true t reference set member

at time T is the version with the most recent

Specref
RefType (field) t effectiveTime

prior to or equal to time T .

...

YES

...

YES (Full)

Optional (Snapshot) 

...

Specref
RefType (field) t active

...

Specref
RefType (data type) t Boolean

...

...

YES

...

NO

...

Specref
RefType (field) t moduleId

...

Specref
RefType (data type) t SCTID

...

...

NO

...

NO

...

Specref
RefType (field) t refsetId

...

Specref
RefType (data type) t SCTID

...

...

Specref
RefType (field) t referencedComponentId

...

Specref
RefType (data type) t SCTID

...

A reference to the

Gloss
Space true t SNOMED CT component

to be included in the

Gloss
t reference set

.

...

Specref
RefType (field) t sourceEffectiveTime

...

Specref
RefType (data type) t Time

...

The effective time of the dependent source

Gloss
t module

(identified by

Specref
RefType (field) t moduleId

). This specifies a version of that

Gloss
t module

, consisting of all

Gloss
t components

that have the same

Specref
RefType (field) t moduleId

as this

Gloss
t refset member

in their states as at the specified

Specref
RefType (field) t targetEffectiveTime

.

...

Specref
RefType (field) t targetEffectiveTime

table.

Refset spec table
Size fs7 RefsetType Module Dependency Reference Set

...

Specref
RefType (data type) t Time

...

The effective time of the target

Gloss
t module

required to satisfy the dependency (identified by

Specref
RefType (field) t referencedComponentId

). This specifies a version of that

Gloss
t module

, consisting of all

Gloss
t components

with the

Specref
RefType (field) t moduleId

specified by

Specref
RefType (field) t referencedComponentId

in their states as at the specified

Specref
RefType (field) t targetEffectiveTime

.

...

Rules and Guidance

Introduction to Modules

Each row in the release files for components and reference set members has a 

Specref
RefType (field) t moduleId

. This refers to the 

Gloss
PreSpace false t module

 that the component is maintained in. Each module is either part of the 

Gloss
PreSpace false t SNOMED International Release

 or part of a single 

Gloss
PreSpace false t SNOMED CT Extension

 . The 

Specref
RefType (field) t moduleId

 has a 

Gloss
PreSpace false t partition-id

 which indicates whether it is part of the 

Gloss
PreSpace false t SNOMED International Release

 and, if not, its 

Gloss
PreSpace false t namespace identifier

 indicates the 

Gloss
PreSpace false t SNOMED CT Extension

 that it belongs to.

A module is simply a collection of 

Gloss
PreSpace false t SNOMED CT components

 maintained as a unit by a single organization. It is the organization 's responsibility to organize the components in each each gloss

Gloss
PreSpace false
t extension

 that it is responsible for into one or more modules, in a way that best fits its business needs.

A module is represented by a 

Gloss
PreSpace false t descendant

 of 

Concept
t 900000000000443000|Module|

 in the metadata 

Gloss
PreSpace false t hierarchy

. The immediate subtype descendants of 

Concept
t 900000000000443000|Module|

 represent groups of modules maintained by an organization and subtypes of these can be used to arrange that organizations modules into a number of groups. For example, all modules maintained by 

Gloss
PreSpace false t SNOMED International

 will be 

Gloss
PreSpace false t children

 of 

Concept
t 900000000000445007|SNOMED International maintained module|

.

At any point in time a 

Gloss
PreSpace false t component

 must be in one, and only one module. It is possible for components and reference set members to be moved between modules (subject to constraints explained elsewhere). In this case, a new row is added to the release file with the same 

Specref
t id

 but with a new 

Specref
RefType (field) t effectiveTime

 and a new 

Specref
RefType (field) t moduleId

. 

Introduction to Module Dependencies

Each 

Gloss
PreSpace false t extension

 must include one or more modules. Each module must be part of either the 

Gloss
PreSpace false t SNOMED International Release

 or one and only one 

Gloss
PreSpace false t extension

.  A module may not move from one 

Gloss
PreSpace false t extension

 to another over time. If components or reference set members in a module are to be moved from an 

Gloss
PreSpace false t extension

 to the 

Gloss
PreSpace false t SNOMED International Release

 or to another 

Gloss
PreSpace false t extension

, they must either be added to an existing or newly created module maintained by the destination organization.

The 

Concept
t 900000000000443000|Module| ShowFormat inline

Gloss
PreSpace false t sub-hierarchy

 does NOT represent dependencies between module. Instead, module dependencies are modeled using the 

Concept
t 900000000000534007|Module dependency reference set|

 .

At the point of release, if any 

gloss

Gloss
PreSpace
false t component

 within a module has changed, then a new row must be added to the 

Concept
ShowParts term t 900000000000534007|Module dependency reference set|

 for each dependency of that module. The 

Specref
RefType (field) t effectiveTime

 of the added rows must set to the date of the new release. The updated

Concept
ShowParts term t 900000000000534007|Module dependency reference set|

 records indicate that some components within the module have been updated in this release. If there have been no additions, updates or inactivations of components or reference set members within a module, then a new

Concept
ShowParts term t 900000000000534007|Module dependency reference set|

 records need not be added unless there is a requirement to declare that the unchanged module is compatible with a later release of the module(s) on which it dependents.

Identifying and Versioning Module Dependencies

id

The recommended practice is for the refset.id column to contain the same identifier for all versions of the dependencies between the same pair of modules. This approach means that at any given time only one version of each module has effective dependencies. The dependencies of earlier versions can be reviewed by reviewing a snapshot for the effectiveTime of the earlier release.

Info
title Value of the id column
An alternative approach has been suggested by some people in which a new identifier is allocated to each dependency of each module. This would then mean that all past dependencies would be visible in a snapshot view. It would also mean that it would be possible release updated dependencies for an existing module version while also releasing more up-to-date versions of the same module with different dependencies. This added flexibility comes at the price of additional complexity and for the time-being the International Release modules continue to use the simpler approach in which each new version of a dependency supersedes the dependency between earlier versions of the same pair of modules.

effectiveTime

The effectiveTime of at least one row for each pair of modules should be the same as the sourceEffectiveTime. Otherwise, there will be a period of time when a snapshot view will not show the dependencies. However, it is theoretically possible for an additional row to be added with a later effectiveTime in cases where an otherwise unchanged release of an extension, declares itself to be compatible with an updated release of the target module (in this case the effectiveTime and targetEffectiveTime are changed but the sourceEffectiveTime remains unchanged.

active

A module dependency only needs to be inactivated if the dependency is found to be erroneous. This is because, the module dependency is specific to a particular version of the source and target module. Therefore, if that dependency was valid at the outset it remains valid indefinitely in respect of those specified module versions, even if the dependencies between subsequent versions differ.

refsetId

Module version dependencies are represented using a single

Concept
t 900000000000534007|Module dependency reference set|

. Thus all module dependency rows have the same refsetId (

Concept
t 900000000000534007|Module dependency reference set (foundation metadata concept)|

).

It is the responsibility of the organization owning and maintaining a dependent module to identify all modules on which it depends. They do this by adding rows to the

Concept
t 900000000000534007|Module dependency reference set|

within the dependent module. Because these added member must be in the dependent module, the

Specref
RefType (field) t moduleId

of the

Gloss
PreSpace false t reference set

member record is also the identifier of the dependent (source) module.

Module Identification

Source Module  (moduleId)

The 

Specref
t moduleId

 column not only indicates that this reference set member is in the specified module, it also indicates that this is the module that is the source of the dependency. As a result, in this reference set the 

Specref
t moduleId

 column is immutable (i.e Mutable=NO). This is an exception to the usual rule and implies that a member of this reference set cannot move from one module to another.

Target Module (referencedComponentId)

The target module on which the source module depends is identified by the

Specref
RefType (field) t referencedComponentId

. Like the source module this is also immutable and this implies that if a module ceases to be dependent on another module, a new row inactivating the dependency can be added but the same member cannot be used to represent a different dependency (even if that dependency is a direct replacement of the inactivated dependency). However as noted above, 

...

Dependencies are specified between module versions, not just dependencies between modules. Therefore, it is possible to specify a dependency from a module released on one date to an earlier version of another module. The version of the dependent module is specified by the

Specref
RefType (field) t sourceEffectiveTime

and the version of the module on which it depends is specified by the

Specref
RefType (field) t targetEffectiveTime

.

Metadata

The following metadata in the "Foundation metadata

Gloss
PreSpace false t concept

"

Gloss
PreSpace false t hierarchy

supports this

Gloss
PreSpace false t reference set

:

Scg expression
Border ridge
900000000000454005 |Foundation metadata concept| 900000000000455006|Reference set| 900000000000534007 |Module dependency|

Excerpt Include
REUSE:Notes on Reference Set Example Tables REUSE:Notes on Reference Set Example Tables nopanel true

Descriptor

The table below shows the descriptor that defines the structure of the

Concept
t 900000000000534007|Module dependency reference set|

.

Note: The table above omits the initial four columns of data present in the release file. These follow the standards versioning pattern

Specref
RefType (field) t id

,

Specref
RefType (field) t effectiveTime

,

Specref
RefType (field) t active

,

Specref
RefType (field) t active

. Additionally, to aid understanding, the table above also shows the

Gloss
PreSpace false t term

from one of the

Gloss
PreSpace false t descriptions

associated with each of the identified

Gloss
PreSpace false t concept

. The release file only contains the

Gloss
PreSpace false t identifier

.

Example Data

Example The table below holds example entries for the

Concept
t 900000000000534007|Module dependency reference set|

in a

Gloss
PreSpace false t snapshot view

of the January 2014

Gloss
PreSpace false t SNOMED CT International Release

.

This

Gloss
PreSpace false t SNOMED CT International Release

contains three modules:

...

In this case all the 2014-01-31 modules depend on 2014-01-31 versions of the other modules. However, in some case a module may depend on an earlier version of another model (e.g. an extension module may be releases after the

Gloss
PreSpace false t SNOMED CT International Release

to which it applies).

Dependencies are not transitive. The fact that

Concept
t 449080006|SNOMED CT to ICD-10 rule-based mapping module|

is dependent on

Concept
t 900000000000207008|SNOMED CT core|

may seem to imply a dependency on

Concept
t 900000000000012004|SNOMED CT model component|

. However, in practice all dependencies must be explicitly specified, not just immediate dependencies.