Method and system for expression evaluation

• US 20080126027A1
• Filed: 09/14/2006
• Published: 05/29/2008
• Est. Priority Date: 09/14/2006
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Hettel, Thomas, Altenhofen, Michael
• Granted Patent: US 7,584,163 B2
• Time in Patent Office: Days
• US Class Current: 703/2
• CPC Class Codes: G06F 8/10 Requirements analysis; Specification techniques

Abstract

A method to analyze impact of changes to a model includes accessing a proposed change to a model. An expression that is relevant to the proposed change is accessed. An instances set associated the expression is obtained. The instance set is evaluated to determine an impact of the proposed change to the model. An application utilizes the expression of a model. An impact analyzer assesses impact of a change to the model by evaluating at least one of the one or more expressions and returning an evaluation set for use by the application.

Claims

1. A system comprising:

an application operative to use a number of expressions on a model; and

an impact analyzer component to assess impact of a change to the model by evaluating the expressions and returning an evaluation set for use by the application.

2. The system of claim 1, wherein the application is further operative to receive the evaluation set to optimize the change to the model.

3. The system of claim 1, wherein the application includes a constraint checker.

4. The system of claim 1, wherein the application includes a model transformation engine.

5. The system of claim 1, wherein the evaluation set includes an evaluation unit.

6. The system of claim 5, wherein the evaluation unit includes a statement and an instance set.

7. The system of claim 5, wherein the instance set includes a starting point and a navigation path.

8. The system of claim 5, wherein the navigation path is a reverse navigation path.

9. The system of claim 1 further comprising:

an event framework component to provide notification regarding changes to the model to the application.

10. The system of claim 1 further comprising:

a filter component to specify notifications to be provided from the event framework component to the application.

11. The system of claim 1 further comprising:

a expression evaluator to evaluate the expressions associated with the application.

12. The system of claim 1, wherein the expressions includes constraints for the model.

13. The system of claim 1, wherein the expressions includes model-to-model transformation rules.

14. The system of claim 1, wherein the model is represented by a modeling language and further defined by the expressions.

15. An apparatus comprising:

a class scope analysis component to receive an expression and provide an identification of an event that is relevant to the expression; and

an instance scope analysis component to access the identification and to associate a navigation path with the event that is relevant to the expression.

16. The apparatus of claim 15 further comprising:

an event cache component to store the identification of the event and the navigation path associated with the event.

17. The apparatus of claim 15, wherein the navigation path includes a reverse navigation path.

18. The apparatus of claim 15, wherein the navigation path includes a reverse navigation path leading from instances affected by the event to context instances of the expression.

19. An article of manufacture comprising:

a machine-readable medium having stored thereon a data structure, the data structure including;

a first field including a statement for a model; and

a second field including an instance set for the statement, the instance set including a starting point and a navigation path, and an instance of the model for which the statement is selectively reevaluated for a change to the model.

20. The apparatus of claim 19, wherein the navigation path includes a reverse navigation path.

21. A method for evaluating change impact, the method comprising:

accessing a proposed change to a model;

accessing an expression relevant to the proposed change;

obtaining an instances set associated with the expression; and

evaluating the instance set to determine an impact of the proposed change to the model.

22. The method of claim 21, further comprising:

identifying the expression relevant to the proposed change by identifying the expression as an expression for which reevaluation should be performed.

23. The method of claim 21, wherein the instance set includes a starting point and a navigation path.

24. The method of claim 23, wherein the navigation path includes a reverse navigation path.

25. The method of claim 21, wherein the expression includes constraints on the model.

26. The method of claim 21, wherein the expression includes model to model transformation rules.

27. A system comprising:

first means for using an expression on a model; and

second means for assessing an impact of a change to the model by evaluating the expression and returning an evaluation set for use by the first means.