Techniques

The following model quality assurance techniques are provided by EMF Refactor.

Provided techniques for Ecore models (to do)

EMF Refactor provides the following model quality assurance techniques for Ecore models (nsUri http://www.eclipse.org/emf/2002/Ecore).

Provided metrics for Ecore models

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Context	Metric	Description
EClass	AvEPEOEC	Average number of EParameters in EOperations of the given EClass.
EClass	ECEOEC	Number of EReferences of other EClasses having the given EClass as type.
EClass	ECEPEC	Number of EParameters within other EClasses having the given EClass as type.
EClass	ECEREC	Number of EReferences of other EClasses having the given EClass as type.
EClass	HAGGEC	Length of the longest path to the leaves in the aggregation hierarchy.
EClass	ICEPEC	Number of EParameters within the EClass having another EClass or interface as type.
EClass	ICEPECEC	Number of EParameters within the EClass having another EClass as type.
EClass	ICEPEIEC	Number of EParameters within the EClass having another interface as type.
EClass	MAXDITEC	Depth of Inheritance Tree (maximum due to multiple inheritance).
EClass	NCEAEC	Number of constant EAttributes of the given EClass.
EClass	NDEROEC	Number of different EClasses being referenced by the given EClass.
EClass	NEAEC	Number of EAttributes of the given EClass.
EClass	NEOEC	Number of EOperations of the given EClass.
EClass	NEPEC	Total number of EParameters in EOperations of the given EClass.
EClass	NEREC	Total number of EReferences of the given EClass.
EClass	NEROEC	Number of EReferences of the given EClass to other EClasses.
EClass	NERSEC	Number of EReferences of the given EClass to itself.
EClass	NFEEC	Number of features (EAttributes and EOperations) of the given EClass.
EClass	NPECEC	Number of EClasses being parts of the given EClass.
EClass	NSUBEC	Number of direct child EClasses of the given EClass.
EClass	NSUBEC2	Number of all child EClasses of the given EClass.
EClass	NSUPEC	Number of direct parent EClasses of the given EClass.
EClass	NSUPEC2	Total number of ancestors of the given EClass.

Provided smells for Ecore models

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Smell	Description
Large EClass	The model contains an EClass owning more features (EAttributes and EOperations) than the specified limit.
Speculative Generality EClass	The model contains an abstract EClass that is inherited by one concrete EClass only.
Unnamed EClass	The model contains an EClass without a name.

Provided refactorings for Ecore models (to do)

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Refactoring	Description
Add EParameter with EClassifier type
Create referenced EClass
Create sub EClass
Create super EClass
Move EAttribute
Move EOperation
Pull up EAttribute
Pull up EOperation
Push down EAttribute
Push down EOperation
Remove empty referenced EClass
Remove empty sub EClass
Remove empty super EClass
Remove EParameter
Rename EAttribute
Rename EClass
Rename EDataType
Rename EEnumLiteral
Rename EOperation
Rename EPackage
Rename EParameter
Rename EReference

Provided techniques for UML2 models (to do)

Provided refactorings for UML2 models (to do)

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<a name="refactorings">UML2 Refactorings</a>
Refactoring	Description
Add Parameter	An operation needs more information from its callers. Therefore, this refactoring adds a parameter to an operation.
Create Associated Class	This refactoring creates an empty class and connects it with a new association to the source class from where it is extracted. The multiplicities of the new association is 1 at both ends. Usually, refactorings Move Attribute and Move Operation are the next steps after this refactoring.
Create Class with Attributes from Parameter List	There is a group of parameters that naturally go together. This refactoring creates a new class and inserts new attributes which conform to the given parameter list. It is a part of refactoring Introduce Parameter Object.
Create Subclass	A class has features (attributes or operations) that are not used in all instances. This refactoring creates a subclass for that subset of features. However, the new subclass has no features. Usually, refactorings Push Down Attribute and Push Down Operation are the next steps after this refactoring.
Create Superclass	This refactoring can be applied when there are at least two classes with similar features (attributes or operations). The refactoring creates a superclass for this set of classes and is normally followed by refactorings Pull Up Attribute and Pull Up Operation. So, the refactoring helps to reduce the duplicate common features spread throughout different classes.
Extract Class	This refactoring extracts interrelated features (attributes and operations) from a class to a new separated class.
Extract Subclass	There are features (attributes and operations) in a class required for a special case only. This refactoring extracts a subclass containing this features.
Extract Superclass	There are two or more classes with similar features. This refactoring creates a new superclass and moves the common features to the superclass. The refactoring helps to reduce redundancy by assembling common features spread throughout different classes.
Extract Superclass (without Pull Up Operation)	This refactoring does the same as Extract Superclass but moves only common attributes to the new superclass.
Hide Attribute	This refactoring hides a public class attribute by setting its visibility to private and creates corresponding getter and setter operations.
Inline Class	There are two classes connected by a 1:1 association. One of them has no further use. This refactoring merges these classes.
Introduce Parameter Object	There is a group of parameters that naturally go together. This refactoring replaces a list of parameters with one object. This parameter object is created for that purpose.
Merge State Features	This refactoring merges several features of two subsequent states of a state chart (a contextual state and a parameter state). More specifically, it moves all actions from the parameter state to the contextual state, redirects all external transitions of the parameter state to the contextual state, and finally removes all inner transitions in between both states. It is part of the refactoring Merge States.
Merge States	This refactoring is used to form a set of states into a single one
Move Attribute	A property (attribute) is better placed in another class which is associated to this class. This refactoring moves this property to the associated class.
Move Operation	This refactoring moves an operation of a class to an associated class. It is often applied when some class has too much behavior or when classes collaborate too much.
Pull Up Attribute	This refactoring removes one property (attribute) from a class or a set of classes and inserts it to one of its superclasses.
Pull Up Operation	This refactoring pulls an operation of a class to its superclass. It is used internally on several classes which inherit from the same superclass. The aim of this refactoring is often to extract identical operations.
Push Down Attribute	An attribute (property) is used only by some subclasses. Move the attribute to only these subclasses. More generally, this refactoring moves the attribute to all subclasses. If it makes sense, the attribute can be removed from some of these afterwards. Sometimes, it also makes sense to keep an attribute in all subclasses to hide it from the superclass.
Push Down Operation	This refactoring pushes an operation from the owning class down to all its subclasses. If it makes sense, the operation can be removed from some of these afterwards. Sometimes, it also makes sense to keep an operation in all subclasses to hide it from the superclass.
Remove Empty Associated Class	There is an empty class that is associated to another class. An associated class is empty if it has no features except for possible getter and setter operations for the corresponding association end. Furthermore, it has no inner classes, subclasses, or superclasses, it does not implement any interfaces, and it is not referred to as type of an attribute, operation or parameter.
Remove Empty Subclass	A superclass has an empty subclass which shall be removed. This class is not associated to another class. It has no features, no inner classes, no further subclasses, and is not associated to other classes. It does not implement any interfaces, and it is not referred to as type of an attribute, operation or parameter.
Remove Empty Superclass	A set of classes has an empty superclass which shall be removed. This class is not associated to another class. It has no features, no inner classes, and is not associated to other classes. It does not implement any interfaces, and it is not referred to as type of an attribute, operation or parameter.
Remove Parameter	A parameter is no longer needed by an operation. Therefore, this refactoring removes this parameter from the parameter list of the operation.
Remove Redundant Transition	This refactoring removes a transition between two states of a state chart if there is already another one between the two states similar to it.
Remove Superclass	There is a set of classes having a superclass that does not make sense anymore. Remove this superclass after pushing remaining features down.
Remove Unused Interface	This refactoring removes a given interface which is not used by and not realized by any classifier and has no sub interface.
Remove Unused Interfaces	This refactoring removes all unused interfaces from the model.
Rename Actor	Renames an existing actor to the inserted new name.
Rename Attribute	Renames an existing class attribute to the inserted new name.
Rename Class	Renames an existing class to the inserted new name.
Rename Operation	Renames an existing operation to the inserted new name.
Rename State	Renames an existing state to the inserted new name.
Rename Use Case	Renames an existing use case to the inserted new name.
Show Attribute	This refactoring shows a private class attribute by setting its visibility to public and removes corresponding getter and setter operations.