Define feature model

Overview

Next Design allows you to define the structure of your feature model in the form of a tree diagram and define constraints between features.

The steps for defining a feature model are described below in the following order:

• Start product line development
• define the structure of the feature model
• Add constraints between features
• Check feature model integrity

Start product line development

To apply product line development to your project, follow these steps:

Operation procedure

1. Select the root project in the Model Navigator.
2. From the project screen, click the [Start] link for the product line.
3. This will allow you to use features that support product line development.

caution

• After you start product line development and save the project, you cannot stop product line development.

Define the structure of a feature model

Switch to Feature Editor

Feature models are created and edited in the feature editor. To switch to the Feature Editor, do the following:

Operation procedure

1. Click [Feature Model] in the product line of the project screen to switch to the feature editor.

You can also switch to the feature editor by following the steps below.

Other operating procedures

1. Switch the navigator to the Product line navigator.
2. Select [Feature Model] directly under the project.

Edit Feature Model

To add features using the Feature Editor, follow the steps below, similar to model editing in the tree diagram.

Operation procedure

1. Select a feature type from the toolbox and drag and drop it onto the feature model.

Feature type	Description
Mandatory Feature	Feature that must be selected if parent feature is selected
Optional Feature	Feature that can be optionally selected if the parent feature is selected
Alternative Feature	A feature that should choose either one of its sibling alternate features when its parent feature is selected
Or Feature	If the parent feature is selected, at least one of its sibling disjunction features should be selected
Feature Group	A node in a tree structure representing a concept that groups multiple features

You can also add features using the following procedure.

Other operating procedures

1. Select the parent feature on the feature editor.
2. Click Product Line > Feature > Create from the ribbon and select the type of feature to add.

caution

• Sub-features below 16 layers cannot be added in the [Feature Tree] view of the Feature Editor. Also, even if there are subfeatures below the 16th level, they will not be displayed. If you want to display/add sub-features below the 16th level, use the [Feature Model] view of the feature editor or use the product line navigator.

Change Feature Type

To change the type of existing features:

Operation procedure

1. Select the features of interest.
2. Change the feature type by doing one of the following:
   • Right-click the selected features and select the type from the context menu Convert View.
   • Click [Product Line] > [Feature] > [Convert View] from the ribbon and select the feature type.

Set initial selection state of features

To change the initial state of a feature to the selected state for a product during configuration, change the property as follows:

Operation procedure

1. Right-click the feature and click Property on the context menu.
2. Check the [Property] > [Basic information] > [Set to initial selection state] check box displayed in the right inspector.

note

• Required features are initially selected, regardless of whether the [Initially selected] checkbox is checked.

Details in feature tree format

To write a detailed description for each feature, do the following:

Operation procedure

1. Switch the view of the feature editor to [Feature Tree].
2. Edit the Description column of the tree grid.

Add constraints between features

To add constraints between features, similar to adding relationships between models in ER diagrams, follow these steps:

Operation procedure

1. Associate features with each other by drag and drop operation.
2. Click a constraint type from the choices that pop up.

constraint type	description
Exclusion	Represents a relationship in which features with exclusion constraints cannot be selected at the same time
Equals	Represents a relationship in which features with interdependence constraints must always be selected at the same time
Requires	Represents a relationship that must always select the dependent feature when the dependent feature is selected

You can also add constraints between features with the following procedure.

Other operating procedures

1. Select the origin and destination features on the feature editor.
2. Click Product Line > Feature > Add Feature Relation from the ribbon and select the constraint type.

Check the integrity of the feature model

Check Consistency

To check the integrity of the feature model structure and constraints, proceed as follows:

Operation procedure

1. Click [Feature Model] in the product line of the project screen to switch to the feature editor.
2. Click [View] > [Pane] > [Error List] on the ribbon to display the error list.
3. Click Product Line > Feature > Check Consistency on the ribbon.
4. If there is an error, it will be displayed in the error list and also displayed on the feature editor.

reference

• For more information on validation, see Reference > Product Line Development Validation.

jump to error

Follow the steps below to jump from the error displayed in the error list to the corresponding location and correct it.

Operation procedure

1. Double-click the error displayed in the error list to jump to the error location on the feature editor.
2. Refer to the error message and correct the feature type or constraints between features.

Cancel error display

To cancel the error display, follow the steps below.

Operation procedure

1. Do one of the following:
   • Click the Clear Error Contents button on the Error List toolbar.
   • From the ribbon [Product Line] > [Feature] > [Consistency Check] Click the [▼] at the bottom and click [Clear Error].