The Goal Diagram
In this way, goal diagrams help to make relationships between goals visible, identify dependencies, and recognize conflicts of interest between stakeholders at an early stage. This makes it possible to evaluate and prioritize goals more specifically and align them with the expectations of the stakeholders.
Goal diagrams are often used as a starting point for deriving requirements and support traceability between goals, stakeholders, and the resulting system requirements.
The diagram
Toolbar
A toolbar is available on the left side of the diagram for working in the diagram. This toolbar is used to create elements and relationships and to add existing elements to the diagram. Which elements and relationships can be created with a button is shown in a tooltip when you move the mouse over a button.
Elements that are created in a diagram are created in the package in which the diagram is also located.
Alternatively, elements of the goal diagram can also be added to the diagram via drag & drop from a view or any package.
Permissible Diagram Elements
Not all element types can be used in this diagram type. The permissible diagram elements are determined by the system context shown as well as by the rules and context elements defined for it. Accordingly, the diagram type supports only the element types intended for this purpose.
The toolbar differs between the Web Client and the Desktop Client.
In the Desktop Client, all buttons provided by the respective diagram type for creating elements and relationships are displayed.
In the Web Client, the toolbar has a more compact layout. Only some of the buttons are displayed directly. Additional element types and relationships are grouped and can be accessed via the context menu of a button. Buttons with additional options are indicated by a dot in the lower-right corner.
New elements are always created according to the same principle: Click the button and then click in the diagram. A creation dialog opens, and as soon as the dialog is confirmed, the element is displayed in the diagram.
White arrow
With the selection tool (arrow), you can:
- Move the diagram background: Click the diagram background and drag it to another position while holding down the left mouse button.
- Edit diagram elements and relationships: Right-click a diagram element or relationship to open the context menu.
- Select diagram elements: Hold down the Shift key and use the left mouse button to draw a frame around the desired element nodes. Selected nodes are highlighted. Click the diagram background to clear the selection.
Add Existing Elements
Opens a selection dialog to add existing system context diagram elements to the diagram.
Create Goal
A goal describes an essential characteristic or a desired property of the system to be developed. Goals help to clarify the purpose and benefit of a requirement or from the perspective of the stakeholders.
Procedure for creating: Click the button and then click the diagram background.
Representation: Goal node
Supported link: Goal, stakeholder, requirement
Create Stakeholder
Stakeholders are individuals or organizations that are affected by or benefit from the future system. To define appropriate and complete requirements, it is important to know the goals of the stakeholders, as the requirements for the system can be derived from these goals.
Procedure for creating: Click the button and then click the diagram background.
Representation: Stakeholder node
Supported link: Goal, stakeholder
Create Requirement
Requirements specify goals in more detail by translating them into clear, implementable, and verifiable specifications for the system.
Procedure for creating: Click the button and then click the diagram background.
Representation: Requirement node
Supported link: Goal, requirement
Create Note
Used to create a note to provide additional information about the diagram or a diagram element.
Procedure for creating: Click the button and then click the diagram background.
Representation: Note node
Supported link: Possible with all permissible diagram elements
Create And Relationship
Expresses that all subgoals must be fulfilled before the higher-level goal is fulfilled.
Procedure for creating: Click the higher-level goal and then click a subgoal.
Representation: Blue line with arrow
Arrow direction: Arrowhead points to the higher-level goal
Create Or Relationship
Expresses that at least one alternative goal must be fulfilled before the higher-level goal is fulfilled.
Procedure for creating: Click the higher-level goal and then click a subgoal.
Representation: Blue, dashed line with arrow
Arrow direction: Arrowhead points to the higher-level goal
Create Own Relationship
Shows that a stakeholder is interested in a goal and benefits from its achievement.
The default stereotype of this relationship type is «own» and is displayed on the relationship line. The name can be changed.
Procedure for creating: Click a stakeholder and then click a goal.
Representation: Gray, dashed line
A weight can be entered after the relationship name by double-clicking the zero.
Create Conflict Relationship
Shows a conflict between two goals. If one of the two goals is fulfilled, fulfillment of the other goal is excluded.
The default stereotype of this relationship type is «conflict» and is displayed on the relationship line. The name can be changed.
Procedure for creating: Click two goals that conflict with each other one after the other.
Representation: Red line with an arrow on both ends
Create Demand Relationship
Expresses that another goal must be fulfilled beforehand or also be fulfilled in order for a goal to be fulfilled. Demand relationships can also be used to illustrate the sequence or priority of goals.
The default stereotype of this relationship type is «demand» and is displayed on the relationship line. The name can be changed.
Procedure for creating: Click first on the goal that must be fulfilled and then on the goal whose achievement depends on it.
Representation: Olive-green line with arrow
Arrow direction: Arrowhead points to the required goal
Create Derive Relationship
Shows that a requirement was derived from a goal.
The default stereotype of this relationship type is «derive» and is displayed on the relationship line. The name can be changed.
Procedure for creating: Click first on a requirement and then on a goal.
Representation: Green line with arrow
Arrow direction: Arrowhead points to the goal
Create Knows Relationship
Shows the relationship between stakeholders.
The default stereotype of this relationship type is «knows» and is displayed on the relationship line. The name can be changed.
Procedure for creating: Click first on the stakeholder who knows the other stakeholder and then on the other stakeholder. The relationship can be one-way or mutual. For a mutual relationship, two directed relationships must be created – one in each direction.
Representation: Orange line with arrow
Arrow direction: Arrowhead points to the stakeholder whom a stakeholder knows
Create Note Relationship
Connects a note to another diagram element.
Procedure for creating: Click the note and then click the element node that is described in more detail by the note.
Representation: gray dashed line
Rules for Creating Relationships
- Multiple AND relationship lines and OR relationship lines cannot be directed to a goal node. Therefore, when creating AND or OR relationships, only the first relationship is directed to the goal node. All further relationships are created by first clicking the relationship line that has already been created and then clicking the subgoal.
- Between two goals, either only one Conflict relationship or only one Demand relationship can exist.
- If two subgoals are connected to a higher-level goal by an AND relationship, no Conflict relationship may be created between these subgoals.
- Circular relationships are not permitted for AND or OR relationships.
- A goal can only have subgoals that are connected to it either by AND or OR relationships.
- Only one relationship line of the same type can be drawn between two goals. If you receive a corresponding error message, first check whether you have hidden the relationship line using the Remove from Diagram command. The Show Relationships command in the context menu of a goal makes all of its relationship lines visible again.
If you receive an error message stating that the relationship you are currently trying to create already exists, you may have created it in another goal diagram. In this case as well, the Show Relationships command in the context menu of a goal will help you.